PROGRAMME AND ABSTRACT BOOK FROM PROTEOME TO PHENOTYPE: ROLE OF POST-TRANSLATIONAL MODIFICATIONS 11 – 13 DECEMBER 2017 UNIVERSITY OF EDINBURGH, UK

PROTEIN POWER

SOCIETY FOR EXPERIMENTAL BIOLOGY CELL SECTION SYMPOSIUM CONTENTS 01 FROM PROTEOME TO PHENOTYPE: ROLE OF POST-TRANSLATIONAL MODIFICATIONS

1. DELEGATE INFORMATION 02

2. PROGRAMME 03

3. POSTER SESSION 07

4. ABSTRACTS 14

5. POSTER ABSTRACTS 30

6. AUTHOR INDEX 63

ORGANISED BY: GERAINT PARRY GARNET STEVEN SPOEL UNIVERSITY OF EDINBURGH, UK CYRIL ZIPFEL THE SAINSBURY LABORATORY, UK

IN COLLABORATION WITH: CELL SECTION SYMPOSIUM DELEGATE INFORMATION 02 CELL SECTION SYMPOSIUM PROGRAMME 03 DELEGATE PROGRAMME INFORMATION

BADGES POSTER SESSION MONDAY 11 DECEMBER 11:45 John Christie Participants are required to wear name badges The poster session will be taking place in the University of Glasgow, United Kingdom at all times for proof of registration, security breakout area between 18:30 – 20:00 on Monday 09:00 REGISTRATION Engineering the function of Phototropin purposes and catering identification. 11 December 2017. Poster presenters are invited to receptor kinases hang their poster on their arrival (Velcro will be 09:25 CS17.4 provided) and are asked to remove their posters by Welcome CATERING 12:15 16:00 on Tuesday 12 December. Any posters left Cyril Zipfel Kris Vissenberg behind will be disposed of. Lunch and refreshments during the symposium Steven Spoel University of Antwerp, Belgium are included in your registration fee and will be Cell symposium co-organisers The auxin-regulated kinase ERULUS controls cell served in the breakout area. LIABILITY wall composition during root hair tip growth in 09:30 Arabidopsis thaliana PLENARY LECTURE Neither the Society for Experimental Biology nor the CS17.5 CERTIFICATE OF ATTENDANCE Jesper Olsen University of Edinburgh will accept responsibility University of , for damage or injury to persons or property during 12:30 Delegates requiring a certificate of attendance Dissecting cell signalling networks the symposium. Participants are advised to arrange Cornelia Klose should visit the SEB registration desk on by quantitative phosphoproteomics their own personal health and travel insurance. Institute of Biology 2, University of Freiburg, their departure. CS17.1 Germany Dynamic regulation of phytochrome B 10:15 REFRESHMENT BREAK/POSTERS VENUE PHOTOGRAPHY activity by phosphorylation SESSION 1 DYNAMIC PHOSPHORYLATION CS17.6 John McIntyre Conference Centre No photographs are to be taken of the speakers Edinburgh First, Pollock Halls and their slides during the symposium. CHAIR: CYRIL ZIPFEL 12:45 LUNCH/POSTERS 18 Holyrood Park Road, Edinburgh EH16 5AY *Please note: The SEB will be taking photos during the event for promotional purposes. If you have any 10.45 SESSION 2 MECHANISMS AND ACTION OF PROTEIN The scientific sessions will be taking place in concerns, please visit the SEB registration desk. Cyril Zipfel SUMOYLATION the Pentland room and the catering and posters The Sainsbury Laboratory, United Kingdom CHAIR: ARI SADANANDOM will be in the breakout area. REGISTRATION Phosphocode-dependent functional dichotomy of the common co-receptor BAK1 in plant signalling 14:00 CS17.2 GARNET WORKSHOP ON PLANT PROTEOMICS The registration desk will be open during the hours Ari Sadanandom of the symposium and a SEB staff member will be Durham University, United Kingdom If you have been selected to attend the plant on hand during the refreshment and lunch breaks 11:15 Rice SUMO protease Overly Tolerant to Salt 1 proteomics workshop on 13 December, you will should you require any assistance. Gitta Coaker targets the transcription factor, OsbZIP23 to have received further information by email. University of California Davis, United States promote drought tolerance in rice The PBL13 kinase negatively regulates the ROS CS17.7 Please visit the SEB registration desk if you TWITTER require information or have any queries. burst in the absence of pathogen perception CS17.3 14:30 We’re looking to increase the conversation at the Andreas Bachmair WI-FI INTERNET ACCESS meeting using Twitter so please get tweeting! Max F. Perutz Laboratories, University of Vienna, Follow the conversation #SEBPTM17 Dept. Biochemistry and Cell Biology, Austria Internet access is available during the symposium SEB – @SEBiology SUMO conjugation - chain formation and links and will be complimentary. Log in details will be GARNet – @GARNetweets to phosphorylation available at the registration desk. CS17.8 CELL SECTION SYMPOSIUM PROGRAMME 04 CELL SECTION SYMPOSIUM PROGRAMME 05 PROGRAMME PROGRAMME

15:00 17:30 TUESDAY 12 DECEMBER 11:45 L Maria Lois Stéphane Ravanel Barbara Korbei CRAG, Spain CEA, Plant Cell Physiology laboratory - University of Natural Resources and Life Sciences Deciphering SUMO conjugation in vivo: multiple Grenoble, France 08:45 REGISTRATION Vienna, Austria regulatory layers controlling plant growth Protein lysine methylation in plants: from proteome Ubiquitin binding and conjugation is important CS17.9 to phenotype…the quest for the Holy Grail 09:00 for the function and localisation of TOL proteins CS17.14 PLENARY LECTURE CS17.21 15:30 Ron Hay Mark Kwaaitaal 18:00 University of Dundee, United Kingdom 12:00 Molecular Plant Pathology, Swammerdam Doris Lucyshyn SUMO-SIM networks regulate the assembly Marco Trujillo Institute for Life Sciences, University of University of Natural Resources and Life of dynamic protein complexes Leibniz Institute for Plant Biochemistry, Germany Amsterdam, Netherlands Sciences Vienna, Austria CS17.17 Phosphorylation and ubiquitination regulate the SUMOylation orchestrates formation of nuclear O-Glycosylation of nuclear and cytosolic proteins Exo70B2 subunit of the exocyst – a convergence bodies that overlap with COP1 photobodies in plants 09:45 REFRESHMENT BREAK/POSTERS point of immune signalling and autophagy CS17.10 CS17.15 CS17.22 SESSION 4 UBIQUITIN-MEDIATED PROTEASOME SYSTEM 15:45 18:15 12:15 LUNCH/POSTERS Justyna Labuz Amanda Chaplin CHAIR: STEVEN SPOEL Jagiellonian University, Poland University of Essex, United Kingdom SESSION 5 REDOX-BASED PTMs IN STRESS AND DEVELOPMENT Sumoylation of phototropins in Glycated peptides triggers H2O2 signalling 10:15 Arabidopsis thaliana in Arabidopsis thaliana Steven Spoel CHAIR: GARY LOAKE CS17.11 CS17.16 University of Edinburgh, United Kingdom Transcriptional regulation by dynamic 13:30 16:00 REFRESHMENT BREAK/POSTERS 18:30 POSTER SESSION ubiquitination Gary Loake CS17.18 University of Edinburgh, United Kingdom SESSION 3 EMERGING PTMS SUMOYLATION 20:00 DINNER Control of plant immune function through LOCATION: SOUTH HALL COMPLEX 10:45 S-nitrosylation CHAIR: PIERS HEMSLEY Luz Irina Calderon-Villalobos CS17.23 Leibniz Institute of Plant Biochemistry (IPB), 16:30 Germany 14:00 Piers Hemsley Auxin-programmed ubiquitylation as a master Frank van Breusegem University of Dundee, United Kingdom signal integration system VIB Ghent, Belgium S-acylation in plants - greasing membrane CS17.19 Oxidative stress signalling in plants. protein function? Towards the proteome and beyond CS17.12 11:15 CS17.24 Emmanuelle Graciet 17:00 Maynooth University, Ireland 14:30 Markus Wirtz Regulation of plant/pathogen interactions Daniel Gibbs Heidelberg University, Germany by the N-end rule pathway University of Birmingham, United Kingdom N-terminal acetylation - a prevalent protein CS17.20 The N-end rule pathway couples PRC2 activity modification that likes to surprise to oxygen availability in flowering plants CS17.13 CS17.25 CELL SECTION SYMPOSIUM PROGRAMME 06 CELL SECTION SYMPOSIUM POSTER SESSION 07 PROGRAMME POSTER SESSION MONDAY 11 DECEMBER

15:00 17:00 Gregory MacNeill Marita Anggarani Eva-Esther Rudolf Katja Baerenfaller University of Guelph, Canada Institute of Plant Molecular Biology, Academia Helmholtz Zentrum München, Germany SIAF, Switzerland Post-translational modifications regulate Sinica, Taiwan Post-translational modification of histones: On-site inspection of ubiquitylation starch branching enzyme 2.2 in Arabidopsis Impaired proteasome function in Arabidopsis Nitric oxide modulates chromatin structure CS17.30 CS17.33 rad23abcd mutant alters auxin homeostasis CS17.26 CS17.39 17:30 Yang Do Choi 15:15 Greg Vert Seoul National University, Korea (South) Ram Nivas Ahirwar Capilla Mata-Perez I2BC CNRS, France OsSGT1 regulates root development and Institute of Plant Molecular Biology, Academia University of Edinburgh, United Kingdom Proteasome-independent roles of growth in rice Sinica, Taiwan Nucleoredoxin 1 (NRX1) selectively rescues lysine63-linked polyubiquitin chains: CS17.34 Arabidopsis deubiquitinase OTU5 is involved plant immunity Insight from sensor-based proteomics in flowering by regulating major repressors CS17.27 CS17.31 Mansoor Azeem Siddiqui FLC/MAF4/MAF5 International Centre for Genetic Engineering CS17.40 15:30 REFRESHMENT BREAK/POSTERS 17:45 and Bio-technology, India Ive De Smet Protein S-Palmitoylation regulates invasion Maura Di Martino TECHNOLOGICAL ADVANCES SESSION 6 VIB, Belgium and apical organelle secretion in human malaria University of Warwick, United Kingdom IN PTM DETECTION The dynamic phosphoproteome parasite, Plasmodium falciparum Combinatorial transcriptional regulation allows identifying novel abiotic stress CS17.35 of the plant defence response CHAIR: ALEX JONES signalling components CS17.41 CS17.32 Arsheed Sheikh

16:00 School of Life Sciences, University Jasmine Pham Alex Jones 18:00 END OF SYMPOSIUM of Warwick, United Kingdom The James Hutton Institute, United Kingdom University of Warwick, United Kingdom Mitogen Activated Protein Kinases (MAPKs) Identification of host membrane proteins that Developing mass spectrometry based proteomic activation post effector recognition in tomato are involved in plant-aphid interactions methods to identify and quantify protein CS17.36 carbonylation in plants CS17.42 CS17.28 Lam Dai Vu VIB-UGent Center for Plant Systems Biology, Inês Luís 16:30 Belgium Instituto de Tecnologia Quimica e Bioiogica Frank Menke Unravelling phosphorylation-mediated signalling Antonio Xavier - Universidade NOVA de Lisboa The Sainsbury Laboratory, United Kingdom in plants at high ambient temperature (ITQB-UNL), Portugal Monitoring phosphorylation and ubiquitination CS17.37 On the quest for posttranslational modifications in pattern recognition receptor signalling governing phosphoenolpyruvate carboxylase CS17.29 Hailong Guo life cycle The Sainsbury Laboratory, United Kingdom CS17.43 Interplay between phosphorylation and acetylation in regulating RPS4/RRS1 immune Luis Lightbourn receptor pair Lightbourn Research Institute, Mexico CS17.38 Transcriptomic profiling of Capsicum annuum in response to high-intensity UV irradiation reveals stress defence signalling CS17.44 CELL SECTION SYMPOSIUM POSTER SESSION 08 CELL SECTION SYMPOSIUM POSTER SESSION 09 POSTER SESSION POSTER SESSION MONDAY 11 DECEMBER MONDAY 11 DECEMBER

Sara Alegre García Doris Lucyshyn Eirini Kaiserli Luis Lightbourn University of Turku, University of Natural Resources and Life Sciences University of Glasgow, United Kingdom Lightbourn Research Institute, Mexico PP2A-B’γ controls methylation of indole Vienna, Austria Understanding the role of sumoylation in Role of post-translational modifications glucosinolates and modulates methionine The role of O-Glycosylation in plant regulating light signalling components in plants that regulates signalling from G-proteins metabolism in Arabidopsis developmental transitions CS17.57 in Capsicum annuum CS17.45 CS17.51 CS17.63 Hui Dong Stuart Sullivan Kyle Bender John Innes Centre, United Kingdom Noriyuki Suetsugu University of Glasgow, United Kingdom The Sainsbury Laboratory, United Kingdom Control of growth by phosphorylation University of Glasgow, United Kingdom Correlation between NPH3 phosphorylation Characterising the role of ELONGATION FACTOR and ubiquitylation of DA1 peptidase RPT2 and NCH1 are key factors for the blue-light status, localisation and phototropic enhancement TU RECEPTOR (EFR) protein kinase activity and CS17.58 receptor phototoropin-signalling pathway in CS17.46 phosphorylation in pattern-triggered immunity land plants CS17.52 Giorgio Perrella CS17.64 University of Glasgow, United Kingdom Michael Skelly Understanding the role of sumoylation in University of Edinburgh, United Kingdom Hannes Vanhaeren Clara Williams regulating light signalling components in plants Dynamic ubiquitination determines NPR1 VIB Center for Plant Systems Biology, Belgium VIB, Belgium CS17.59 transcriptional coactivator activity The role of the peptidase DA1 and the E3-ligase Repression of ‘LURP’ regulon by the F-BOX CS17.47 BIG BROTHER in regulating cell proliferation and protein and JA receptor, COI1 senescence in plants Anne Marie Labandera CS17.65 CS17.53 University of Calgary, Canada Joanna Landymore The Arabidopsis thaliana Rhizobiale-like University of Sheffield, United Kingdom Hannah Tedds Nelson Serre phosphatase 2 is a novel D-group Mitogen Understanding the role of Nitrate reductases University of Birmingham, United Kingdom University Grenoble Alpes, France Activated Protein Kinase (MAPK) tyrosine- NIA1 and NIA2 under abiotic stresses VERNALIZATION2 is an oxygen- and nitric Lysine methylation of non-histone proteins is specific PPP-family protein phosphatase CS17.48 oxide-regulated substrate of the N-end rule involved in the response of Arabidopsis plants CS17.60 pathway of proteolysis to a stress induced by cadmium CS17.66 Dionne Turnbull CS17.54 Mirko Pavicic University of Dundee, United Kingdom University of , Finland What ‘R’ you doing here? Investigating the role of Rumana Keyani Upendo Lupanga Genomic and phenomic screens for flower related S-acylation in plant disease resistance proteins COMSATS Institute of information technology University of Dundee, United Kingdom RING type Ubiquitin E3 ligases in Arabidopsis CS17.49 Islamabad, Pakistan Dynamic S-acylation in plants CS17.61 CS17.55 Nucleoredoxin guards against oxidative stress by protecting antioxidant enzymes Young Hee Joung Mhairi Davidson CS17.67 Chonnam National University, Korea (South) Dae Sung Kim IMCSB University of Glasgow, United Kingdom Functional analysis of CYP707A70 gene (ABA The Sainsbury Laboratory, United Kingdom Understanding the role of sumoylation in 8’-hydroxylases) from Hot Pepper (Capsicum A downy mildew effector imposes host regulating light signalling components in plants Charlotte Hurst annuum) in transgenic tobacco and tomato susceptibility by modulating the activity of CS17.62 Dundee University at the James Hutton Institute, CS17.50 a host RING E3 ligase required for immunity United Kingdom CS17.56 S-acylation: What the FLS2 is going on? CS17.68 CELL SECTION SYMPOSIUM POSTER SESSION 10 CELL SECTION SYMPOSIUM POSTER SESSION 11 POSTER SESSION POSTER SESSION MONDAY 11 DECEMBER MONDAY 11 DECEMBER

Alberto Campanaro Lucas Frungillo Mariia Stanovova Hanna Hõrak Durham University Biosciences Department, University of Edinburgh, United Kingdom Lomonosov State University, Russia University of Sheffield, United Kingdom United Kingdom Protein S-nitrosylation in immune-induced Role of proteasomes in non-specific immune Improvement of plant water use efficiency via SUMO proteases OTS1 and 2 control filament hormonal networks response of marine annelids modification of stomatal signalling pathways elongation through a DELLA-dependent CS17.75 CS17.81 CS17.87 mechanism CS17.69 Maiju Laurila Linda Millyard Mark Bailey University of Dundee, United Kingdom Durham University, United Kingdom University of Birmingham, United Kingdom Jose Monreal Discovering de-S-acylating enzymes Ubiquitination in wheat defence against Characterisation of the N-terminal Acetylation University of Sevilla, Spain in Arabidopsis Septoria fungus branch of the N-end rule pathway of protein Post-translational modifications (PTMs) in plant CS17.76 CS17.82 degradation in Arabidopsis thaliana proteins: Phosphoenolpyruvate carboxylase CS17.88 (PEPC) as a case of study Lisa Asseck Bruna Marques dos Santos CS17.70 ZMBP Tuebingen, Germany University of Copenhagen, Denmark Maria Derkacheva IP-MS identifies a membrane receptor An Omics approach to investigate the effect The Sainsbury Laboratory, Norwich Research Beatriz Orosa of the Arabidopsis GET pathway of climate change in Eucalyptus Park, Norwich, United Kingdom Department of Biosciences, Durham University, CS17.77 CS17.83 Dynamic interplay between phosphorylation and United Kingdom ubiquitination during plant receptor kinase- Transcriptional analysis of OTS SUMO protease Rashid Alijani Ardeshir Adnan Khan Niazi mediated immunity mutants reveals new signalling nodes that Khoramshar University of Marine Science CABB University of Agriculture Faisalabad, CS17.89 promote biotic stress tolerance in plants and Technology, Iran Pakistan CS17.71 CYP1A gene expression as a basic factor for Self-protection of Arabidopsis cytosolic malate Sebastien Lambertucci fipronil toxicity in Caspian kutum fish dehydrogenase against oxidative stress Royal Holloway University of , Dhiya Zawawi CS17.78 CS17.84 United Kingdom University of Sheffield, United Kingdom Identification of barley exta-haustorial membrane Expression-functional studies of Nicola Leftley Thomas DeFalco proteins in the haustoria of the obligate biotrophic phosphoenolpyruvate carboxylase kinase University of Nottingham, United Kingdom The Sainsbury Laboratory, United Kingdom fungal pathogen, Blumeria graminiss f.sp hordei (PEPCK) Dissecting the molecular mechanism regulating Identifying and characterising substrates of CS17.90 CS17.72 lateral root hydropatterning the immune kinase BIK1 CS17.79 CS17.85 Hansjörg Stampfl Fenella Croley Center for Health Bioresources, Austrian Institute Durham University, United Kingdom Baris Uzilday Adnan Khan Niazi of Technology, Austria Fifty Shades of SUMO: its role in immunity Ege University, CABB University of Agriculture, Faisalabad, Phosphorylation-mediated stress signalling and at the fulcrum of growth-defense balance Disruption of N-linked protein glycosylation Pakistan and redox regulation CS17.73 alters polyamine oxidase signalling pathway The siRNA suppressor RTL1 is redox-regulated CS17.91 in Arabidopsis thaliana through glutathionylation of a conserved cysteine Rebecca Gwyther CS17.80 in the double-stranded-RNA-binding domain Durham University, United Kingdom CS17.86 Exploiting protein modification systems to boost crop productivity: SUMO in the focus CS17.74 CELL SECTION SYMPOSIUM POSTER SESSION 12 SOCIETY FOR EXPERIMENTAL BIOLOGY PRESENTS: SEB FLORENCE 2018 3–6 JULY 2018 POSTER SESSION FIRENZA FIERA CONGRESS AND EXHIBITION CENTRE MONDAY 11 DECEMBER S E B I O L O G Y. O R G #SEBAMM

Laura Moody University of Oxford, United Kingdom Identification of No Gametophores 1 (PpNOG1), a novel regulator of three-dimensional growth in Physcomitrella patens CS17.92

Heather Grey University of Edinburgh, United Kingdom MASTERS Proteasome-associated HECT-type ubiquitin ligase activity is required for plant immunity CS17.93 OF BIOLOGY Becky Morrell Durham University, United Kingdom Insecticidal fusion proteins: How does the orientation of the toxin to the carrier affect toxicity to insects? CS17.94

Hirofumi Nakagami Max Planck Institute for Plant Breeding Research, Germany

Phosphoproteomic approach to survey molecular SESSION TOPICS WILL INCLUDE: components of plant immune system CS17.95 SCIENCE ACROSS ANIMAL BIOLOGY OTHER ANIMAL BIOLOGY SESSIONS CELL BIOLOGY BOUNDARIES – ANIMAL, • OPEN ANIMAL BIOLOGY PLANT AND CELL BIOLOGY BIOMECHANICS • FUNCTIONAL ORGANISATION OF THE • BIOMECHANICS AND CLIMATE CHANGE PLANT BIOLOGY NUCLEAR PERIPHERY Frederica Theodoulou METABOLIC DIVERSITY • OPEN BIOMECHANICS • GREEN MICROBES (ANIMAL, PLANT AND CELL BIOLOGY) • CLIMATE CHANGE IMPACT ON URBAN • SEQUENCING FROM LAB TO FIELD AND Rothamsted Research, United Kingdom PROXIMATE AND ULTIMATE DRIVERS AND NATURAL FORESTS THE POST GENOMIC ERA N-terminal peptide enrichment as a tool for STRESS: FROM CELLULAR MECHANISMS OF BEHAVIOUR • ENHANCING PLANT PHOTOSYNTHESIS • SYSTEMS ANALYSES OF TO ORGANISMAL RESPONSES AND • GENERALITY OF THE ‘PACE-OF-LIFE WITH BIOPHYSICAL CO2 MULTICELLULARITY COMPLEXITY studying targeted protein degradation pathways CONSERVATION SYNDROME’ CONCENTRATING MECHANISMS • QUANTITATIVE SYNTHETIC BIOLOGY and proteolytic events (ANIMAL AND CELL BIOLOGY) • INTRASPECIFIC VARIATION • EPIGENETIC MEMORY AND • PUMPING IONS AS A RESPONSE TO IN RESPONSES TO STRESS: WHY ENVIRONMENTAL ADAPTATION SEB+ CS17.96 STRESS FROM AQUATIC HABITAT INDIVIDUALS MATTER? • FROM GENOME TO GENOMES TRANSITIONS: CELLULAR AND • THE ROLE OF INDIVIDUAL • MORPHOGENESIS IN NON-FLOWERING • BIOLOGY EDUCATION AND MOLECULAR MECHANISMS RELATED VARIATION IN THE BEHAVIOUR OF PLANTS CLASS SIZE: CHALLENGES, TO EVOLUTIONARY CHANGES ANIMAL GROUPS • PLANT BIOTECHNOLOGY FOR HEALTH OPPORTUNITIES AND STRATEGIES Kevin Goslin • THE ROLE OF THE MITOCHONDRIA AND NUTRITION FOR SCALING TEACHING Maynooth University, Ireland IN ENVIRONMENTAL ADAPTATION THERMOBIOLOGY • PLANT TEMPERATURE PERCEPTION • CAREER DEVELOPMENT WORKSHOPS AND DISEASE • CARDIO-RESPIRATORY ADAPTATIONS AND RESPONSES FOR YOUNG RESEARCHERS Investigating the degradation of Arabidopsis • ADVANCES IN NON-INVASIVE TO ENVIRONMENTAL CHANGE • SHAPING ROOT ARCHITECTURE • DIVERSITY DINNER RIN4 fragments after cleavage by the MONITORING OF STRESS IN THE • MITOCHONDRIA IN CHANGING - FROM NUTRIENT SENSING AND • EMBRACING YOUR ETHICAL REVIEW FIELD AND LABORATORY: CLIMATES: BIOSENSORS AND TROPISMS TO SYSTEMIC SIGNALS BODY - A WIN-WIN SITUATION Pseudomonas syringae effector AvrRpt2 APPLICATIONS FOR CONSERVATION MEDIATORS OF ANIMAL RESILIENCE AND DECISION MAKING • MEET THE ACADEMICS CS17.97 • OCEAN WARMING AND ACIDIFICATION: GENERAL CELL AND PLANT BIOLOGY WHAT UNDERLYING MECHANISMS (CELL AND PLANT BIOLOGY) CAN REVEAL ABOUT IMPACTS OF MULTIPLE STRESSORS CELL SECTION SYMPOSIUM ABSTRACTS 14 CELL SECTION SYMPOSIUM ABSTRACTS 15

FROM PROTEOME TO PHENOTYPE: C S 17.3 THE PBL13 KINASE NEGATIVELY C S 17.4 ENGINEERING THE FUNCTION REGULATES THE ROS BURST IN THE OF PHOTOTROPIN RECEPTOR KINASES ROLE OF POST-TRANSLATIONAL ABSENCE OF PATHOGEN PERCEPTION MONDAY 11 DECEMBER 2017 11:45 MONDAY 11 DECEMBER 2017 11:15 MODIFICATIONS JOHN CHRISTIE (UNIVERSITY OF GLASGOW, GITTA COAKER (UNIVERSITY OF CALIFORNIA UNITED KINGDOM) DAVIS, UNITED STATES), DONGHYUK LEE (UNIVERSITY OF CALIFORNIA DAVIS, UNITED [email protected] STATES), DANIEL LIN (DONALD DANFORTH PLANT C S 17.1 DISSECTING CELL C S 17.2 PHOSPHOCODE-DEPENDENT Phototropins (phot1 and phot2) are plasma membrane- SCIENCE CENTER, UNITED STATES) SIGNALLING NETWORKS BY FUNCTIONAL DICHOTOMY OF THE associated protein kinases that function to regulate QUANTITATIVE PHOSPHOPROTEOMICS COMMON CO-RECEPTOR BAK1 IN [email protected] a wide range of responses in plants. These include PLANT SIGNALLING chloroplast relocation movements, leaf positioning Plant surface localized immune receptors, termed MONDAY 11 DECEMBER 2017 09:30 and expansion, stomatal opening and phototropism, pattern recognition receptors, recognize conserved MONDAY 11 DECEMBER 2017 10:45 all of which influence a plant’s photosynthetic microbial features, resulting in pattern-triggered JESPER V OLSEN (UNIVERSITY OF COPENHAGEN, competence by improving the efficiency of light immunity. Reactive oxygen species (ROS) play pivotal DENMARK) CYRIL ZIPFEL (THE SAINSBURY LABORATORY, capture, reducing photodamage, and regulating roles in PTI as signalling molecules. The NADPH UNITED KINGDOM) gas exchange between leaves and the atmosphere. oxidase RBOHD is a major source of ROS production [email protected] Research over the last two decades has improved our in Arabidopsis and RBOHD is positively regulated [email protected] understanding of how these autophosphorylating Mass Spectrometry based quantitative phospho- by N-terminal phosphorylation through multiple kinases are activated, how they are regulated and how proteomics is emerging a powerful technology for Plants rely on cell surface-localized receptors kinases kinases. Recently, we identified and characterised they initiate signalling from the plasma membrane. global analysis of cellular signalling networks. In for their survival. Plant receptor kinases form ligand- the PBL13 kinase. PBL13 exhibits a unique C-terminal Here, we outline several engineering strategies aimed particular tyrosine phosphorylation (pTyr) is of great induced complexes with shape-complementary co- repeat region and knockout lines exhibit an enhanced at modulating phototropin receptor function in plants. importance in eukaryotic cells due to its crucial role in receptors, which are required for their activation. The ROS burst and increased RBOHD abundance. PBL13 These include approaches aimed at altering the light- regulating intracellular signalling networks controlling best-characterised plant co-receptor is BAK1 (also is able to phosphorylate RBOHD’s C-terminus at regulation of phototropin kinase activity, the outcome cell fate decisions such as proliferation, migration, called SERK3), which controls immunity, as well as conserved residues. C-terminal phosphorylation acts of which could lead new possibilities for altering differentiation, cell cycle progression and apoptosis. We several aspects of growth and development, through to negatively regulate RBOHD enzymatic activity plant growth through changes in photosynthetic employed quantitative phosphoproteomics to delineate association with leucine-rich repeat receptor kinases. and protein accumulation. Data will also be presented performance. We also describe how recently developed receptor tyrosine kinase (RTK) signalling dynamics The mechanisms by which BAK1 control the activation highlighting the interplay between C-terminal optogenetic tools are being used to manipulate activated by different ligands leading to differential of these receptors is however still mostly unknown. phosphorylation and ubiquitination of RBOHD. phototropin-mediated changes in ion transport, cellular outcomes. We quantified thousands of pTyr Here, we report key regulatory events controlling Taken together, these data indicate that PBL13 acts to especially K+ . Finally, we show how the activity of events as a function of ligand and stimulation time the function of BAK1 and more generally leucine- appropriately regulate RBOHD activity in the absence phototropin kinases can be successfully engineered and revealed RTK-specific regulation of pTyr sites on rich repeat receptor kinases. Through a combination of pathogen perception. to accommodate non-natural ATP analogues. key adaptor and signalling molecules, which fine-tune of phospho-proteomics and targeted mutagenesis, This chemical-genetic approach now offers new cell migration and proliferation. These results, based we identified five phosphosites that are required for possibilities to track and identify substrates targets on a multidisciplinary approach, which combines BAK1 immune function in Arabidopsis thaliana. The for the phototropins and other related AGCVIII kinases. quantitative phosphoproteomics and functional assays, inability to phosphorylate on any of these residues identify ligand-dependent mechanisms for the control abolish cellular immune outputs induced by the of RTK signalling and for the specification of long-term bacterial pathogen-associated molecular pattern cellular outcomes. flg22, and leads to impaired anti-bacterial immunity. Strikingly, these phosphosites are yet not required for BAK1/SERK-dependent brassinosteroid-regulated plant growth. Beyond revealing a critical role for BAK1 C-terminal tail phosphorylation, we also identified a conserved phosphorylated tyrosine residue that is required for the function of BAK1 and potentially that of ~80% of Arabidopsis leucine-rich repeat receptor kinases. Our results thus suggest a phosphocode-based dichotomy of BAK1 functions in plant signalling, and provide novel insights into receptor kinase activation, which have broad implications to our understanding of how plants grow, develop and respond to their changing environment. CELL SECTION SYMPOSIUM ABSTRACTS 16 CELL SECTION SYMPOSIUM ABSTRACTS 17

C S 17.5 THE AUXIN-REGULATED in RH cells and localised to the apical RH plasma gradually control photomorphogenic development increased abundance of OsbZIP23 and increased KINASE ERULUS CONTROLS CELL WALL membrane. ERU regulates CW composition in RHs and depending on the light and temperature conditions. drought responsive gene expression while OsOTS1 modulates pectin dynamics through negative control Phytochromes including phyB are phosphoproteins, overexpressing lines show reduced levels of OsbZIP23 COMPOSITION DURING ROOT HAIR TIP of pectin methylesterase (PME) activity. Mutant eru primarily phosphorylated at their N-terminus and leading to suppressed drought responsive gene GROWTH IN ARABIDOPSIS THALIANA RHs accumulate de-esterified homogalacturonan have been assigned with autophosphorylation- as expression. Our data reveals a mechanism where rice (HG) and exhibit aberrant pectin Ca2+ binding site well as kinase activity. I will present our latest findings plants govern ABA dependant drought responsive gene MONDAY 11 DECEMBER 2017 12:15 oscillations and increased PME activity. Up to 80% of about dynamic phosphorylation of phyB and discuss expression by controlling the stability of OsbZIP23 the eru RH phenotype is rescued by pharmacological how phosphorylation modulates phyB mediated by SUMO conjugation through manipulating specific KRIS VISSENBERG (UNIVERSITY OF ANTWERP, supplementation with a PME inhibiting catechin responses to light and temperature. Particular SUMO protease levels. BELGIUM), SÉBASTJEN SCHOENAERS extract. ERU transcription levels are altered in emphasis will be on the molecular mechanism (UNIVERSITY OF ANTWERP, BELGIUM), DARIA specific CW-related RH mutants, suggesting it is a how phosphorylation alters phyB activity by BALCEROWICZ (UNIVERSITY OF ANTWERP, target for feedback regulation. Loss of ERU alters the modulating the dark reversion process and in what BELGIUM), GORDON BREEN (UNIVERSITY phosphorylation status of FERONIA (FER) and H+ way this can be related to the observed effects of C S 17.8 SUMO CONJUGATION - OF BRISTOL, UNITED KINGDOM), KRISTINE CHAIN FORMATION AND LINKS HILL (CENTRE FOR PLANT INTEGRATIVE -ATPase 2 (AHA2), regulators of apoplastic pH during phyB phosphorylation on physiological responses. BIOLOGY, UNIVERSITY OF NOTTINGHAM, cell growth. Furthermore, both AHA2 and ERU are TO PHOSPHORYLATION UNITED KINGDOM), MALGORZATA ZDANIO differentially phosphorylated in response to auxin. (UNIVERSITY OF ANTWERP, BELGIUM), GRÉGORY We conclude that ERULUS is a key auxin-controlled MONDAY 11 DECEMBER 2017 14:30 MOUILLE (INRA VERSAILLES, FRANCE), TARA regulator of CW composition and pectin dynamics C S 17.7 RICE SUMO PROTEASE OVERLY J HOLMAN (CENTRE FOR PLANT INTEGRATIVE during RH tip growth, possibly through control of CW TOLERANT TO SALT 1 TARGETS THE ANDREAS BACHMAIR (MAX F. PERUTZ LABORATORIES, UNIVERSITY OF VIENNA, DEPT. BIOLOGY UNIVERSITY OF NOTTINGHAM, pH via FER and AHA2. TRANSCRIPTION FACTOR, OSBZIP23 TO UNITED KINGDOM), JAESUNG OH (CENTRE FOR PROMOTE DROUGHT TOLERANCE IN RICE BIOCHEMISTRY AND CELL BIOLOGY, AUSTRIA), PLANT INTEGRATIVE BIOLOGY, UNIVERSITY KONSTANTIN TOMANOV (MAX F. PERUTZ OF NOTTINGHAM, UNITED KINGDOM), MICHAEL LABORATORIES, UNIVERSITY OF VIENNA, DEPT. MONDAY 11 DECEMBER 2017 14:00 WILSON (CENTRE FOR PLANT INTEGRATIVE C S 17.6 DYNAMIC REGULATION BIOCHEMISTRY AND CELL BIOLOGY, AUSTRIA), BIOLOGY, UNIVERSITY OF NOTTINGHAM, UNITED OF PHYTOCHROME B ACTIVITY ELLA NUKARINEN (UNIVERSITY OF VIENNA, ARI SADANANDOM (DURHAM UNIVERSITY, DEPT. OF ECOGENOMICS AND SYSTEMS BIOLOGY, KINGDOM), NATALIA NIKONOROVA (VIB/GHENT BY PHOSPHORYLATION UNITED KINGDOM) UNIVERSITY, BELGIUM), LAM DAI VU (VIB/ AUSTRIA), LILIAN NEHLIN (MAX F. PERUTZ GHENT UNIVERSITY, BELGIUM), IVE DE SMET LABORATORIES, UNIVERSITY OF VIENNA, MONDAY 11 DECEMBER 2017 12:30 [email protected] (VIB/GHENT UNIVERSITY, BELGIUM), RANJAN DEPT. BIOCHEMISTRY AND CELL BIOLOGY, AUSTRIA), WOLFRAM WECKWERTH (UNIVERSITY SWARUP (CENTRE FOR PLANT INTEGRATIVE Conjugation of SUMO (Small Ubiquitin-like CORNELIA KLOSE (INSTITUTE OF BIOLOGY 2, OF VIENNA, DEPT. OF ECOGENOMICS AND BIOLOGY, UNIVERSITY OF NOTTINGHAM, UNITED Modifier) protein to cellular targets is emerging as a UNIVERSITY OF FREIBURG, GERMANY), ANDRÁS SYSTEMS BIOLOGY, AUSTRIA) KINGDOM), WINNOK DE VOS (UNIVERSITY VICZIÁN (INSTITUTE OF PLANT BIOLOGY, very influential protein modification system. Once OF ANTWERP, BELGIUM), ISABEL PINTELON BIOLOGICAL RESEARCH CENTRE SZEGED, covalently bound SUMO conjugation can change the [email protected] (UNIVERSITY OF ANTWERP, BELGIUM), DIRK ), ÉVA ÁDÁM (INSTITUTE OF PLANT stability or functionality of its cognate target proteins. ADRIAENSEN (UNIVERSITY OF ANTWERP, BIOLOGY, BIOLOGICAL RESEARCH CENTRE SUMO protease can rapidly reverse SUMO conjugation Modification of substrates by the small ubiquitin- BELGIUM), CLAIRE GRIERSON (UNIVERSITY SZEGED, HUNGARY), EBERHARD SCHÄFER making this modification system highly dynamic. A related modifier SUMO occurs usually by covalently OF BRISTOL, UNITED KINGDOM), MALCOLM J (INSTITUTE OF BIOLOGY 2, UNIVERSITY OF major factor in the variation of SUMO-target function linking one SUMO moiety to the substrate. However, BENNETT (CENTRE FOR PLANT INTEGRATIVE FREIBURG, GERMANY), FERENC NAGY (INSTITUTE is the balance between the conjugated/de-conjugated SUMO chains have also been detected, and SUMO BIOLOGY, UNIVERSITY OF NOTTINGHAM, OF PLANT BIOLOGY, BIOLOGICAL RESEARCH forms. The mechanistic role of these regulatory SUMO ligases have been identified that promote SUMO chain UNITED KINGDOM) CENTRE SZEGED, HUNGARY) proteases in mediating stress responses has not been formation (PIAL1 and2 in Arabidopsis; Tomanov et defined in any crops. In this study, we reveal the role of al., 2014, Plant Cell 26, 4547-4560). SUMO chains can [email protected] [email protected] the SUMO protease, OsOTS1 in mediating tolerance be formed even without ligase, by an in vitro system to drought in rice. OsOTS1 depleted transgenic plants consisting of SUMO, SUMO activating enzyme SAE Root hair (RH) growth is an auxin-regulated process Phytochromes are dimeric red/far-red light absorbing accumulate more ABA and exhibit more productive and SUMO conjugating enzyme SCE. We found that dependent on localised synthesis, secretion and photoreceptors that can photo-interconvert agronomic traits during drought whilst OsOTS1 Lys to Arg changes in the amino-terminal region of SCE modification of RH tip cell wall (CW). Direct targets of between two conformations: Pr and Pfr whereby the overexpressing lines are drought sensitive but ABA can either increase, or decrease SUMO chain synthesis. auxin signalling in RHs and a direct link between auxin amount of the Pfr form in the nucleus is critical for insensitive. Drought and ABA treatment stimulates the The SCE mutations investigated have a similar effect and RH CW signalling are still lacking. We identified physiological activity of phytochromes. In addition degradation of OsOTS1 protein indicating that SUMO when chain formation is enhanced by PIAL ligases, ERULUS (ERU), an auxin-induced Arabidopsis receptor- to photoconversion, Pfr can spontaneously revert back conjugation is an important response to drought stress suggesting mechanistic similarity for SUMO chain like kinase whose transcription is directly regulated by to Pr in a light independent thermal relaxation process in rice achieved through down-regulation of OTS1/2 synthesis with and without ligase. A substrate was ARF7 and ARF19 transcription factors. ERU belongs called dark reversion. For phytochrome B (phyB), the activity. We reveal that OsOTS1 SUMO protease identified that is decorated with a SUMO chain in the to the Catharanthus roseus RECEPTOR-LIKE KINASE dominating phytochrome in light grown plants, dark directly targets the ABA and drought responsive in vitro system consisting of SAE and SCE, whereas 1-LIKE (CrRLK1L) subfamily of putative CW sensor reversion is an essential mechanism determining its transcription factor OsbZIP23 for de-SUMOylation other substrates tested in the same reaction receive proteins. Visualisation of the fluorescent ERU-GFP modes of action: it enables phyB to act as dynamic affecting its stability. OsOTS-RNAi lines show a single SUMO moiety only. SCE can therefore select fusion protein revealed that ERU is expressed only light quality-/ quantity- and temperature sensor to CELL SECTION SYMPOSIUM ABSTRACTS 18 CELL SECTION SYMPOSIUM ABSTRACTS 19

substrates for either mono-sumoylation, or for addition C S 17.1 0 SUMOYLATION ORCHESTRATES C S 17.1 1 SUMOYLATION OF C S 17.1 2 S-ACYLATION IN PLANTS of a SUMO chain. FORMATION OF NUCLEAR BODIES THAT PHOTOTROPINS IN ARABIDOPSIS - GREASING MEMBRANE PROTEIN Mutant plants with defects in SUMO conjugation FUNCTION? were compared to WT plants regarding phosphoprotein OVERLAP WITH COP1 PHOTOBODIES THALIANA content. Some 50 phosphoproteins could be identified that had significantly changed abundance, implying MONDAY 11 DECEMBER 2017 15:30 MONDAY 11 DECEMBER 2017 15:45 MONDAY 11 DECEMBER 2017 16:30 that their occurrence is influenced by SUMO MARK ACJ KWAAITAAL (MOLECULAR PLANT JUSTYNA M LABUZ (JAGIELLONIAN UNIVERSITY, PIERS HEMSLEY (UNIVERSITY OF DUNDEE, conjugation (Nukarinen et al., 2017, Plant Journal PATHOLOGY, SWAMMERDAM INSTITUTE FOR POLAND), DOMINIKA JAGIELLO FLASINSKA UNITED KINGDOM) 91, 505-517). Interestingly, these proteins frequently LIFE SCIENCES, UNIVERSITY OF AMSTERDAM, (JAGIELLONIAN UNIVERSITY, POLAND), OLGA contained predicted SUMO attachment sites, and NETHERLANDS), MAGDALENA J MAZUR SZTATELMAN (INSTITUTE OF BIOCHEMISTRY AND [email protected] SUMO interaction motifs. They may thus be nodes that (LABORATORY FOR VIROLOGY, DEPARTMENT FOR BIOPHYSICS PAS, POLAND), PAWEL HERMANOWICZ integrate sumoylation and phosphorylation signals, PLANT SCIENCES, WAGENINGEN UNIVERSITY, (JAGIELLONIAN UNIVERSITY, POLAND), S-acylation is a lipid based post-translational to affect cellular responses. NETHERLANDS), HARROLD A VAN DEN BURG ANETA BAZANT (JAGIELLONIAN UNIVERSITY, modification of proteins thought to alter a proteins (MOLECULAR PLANT PATHOLOGY, SWAMMERDAM POLAND), AGNIESZKA K BANAS (JAGIELLONIAN physical properties leading to alterations in how a INSTITUTE FOR LIFE SCIENCES, UNIVERSITY UNIVERSITY, POLAND), WOJCIECH STRZALKA protein interacts with the membrane environment. OF AMSTERDAM, NETHERLANDS) (JAGIELLONIAN UNIVERSITY, POLAND), HALINA It is unique amongst lipid modifications as it C S 17.9 DECIPHERING SUMO GABRYS (JAGIELLONIAN UNIVERSITY, POLAND) is reversible; this lends it the ability to act as a CONJUGATION IN VIVO: MULTIPLE [email protected] regulatory mechanism. We have shown that ~40% REGULATORY LAYERS CONTROLLING [email protected] or the plant membrane proteome is S-acylated and Plant growth is strongly controlled by the PIF PLANT GROWTH that S-acylation affects both integral and peripheral transcription factors during the dark/light cycle. Phototropins (phots) are plant UV-A/blue light membrane proteins. The study of S-acylation is still The same growth pathway is also activated when photoreceptors which fine tune plant photosynthetic MONDAY 11 DECEMBER 2017 15:00 in its infancy but we have found that S-acylation is plants experience high temperatures. The last efficiency by controlling growth responses and key for the function of two plant-defining groups L. MARIA LOIS (CRAG, SPAIN), ABRAHAM MÁS process is called thermomorphogenesis. Increased organellar movements. The phototropin N - terminal of proteins; the cellulose synthase complex (CSC) (CRAG-CENTER FOR RESEARCH IN AGRICULTURAL ambient temperatures also compromise plant part contains two LOV photosensory domains. The and receptor-like kinases (RLKs). We recently GENOMICS, SPAIN), LAURA CASTAÑO-MIQUEL immune responses. The SUMO E3 ligase SIZ1 directly C-terminus consists of a serine-threonine kinase, demonstrated that the CSC, a hetero-18-mer, contains (CRAG-CENTER FOR RESEARCH IN AGRICULTURAL coordinates both processes, suggesting a novel role which autophosphorylates the photoreceptor upon ~100 S-acyl groups and is the most heavily S-acylated GENOMICS, SPAIN) for SIZ1-dependent SUMOylation in the crosstalk light exposure. Here we show that two phototropins protein complex ever described. We will discuss the between growth and immunity. Firstly, loss of SIZ1 of Arabidopsis thaliana, phot1 and phot2, may also be [email protected] roles and implications of S-acylation in CSC function. function leads to a constitutive immune response. modified by SUMO (small ubiquitin-like modifier). BIFC Receptor-like kinases are responsible for perception Posttranslational modification with Small Ubiquitin- Secondly, SIZ1 stability is controlled by the E3 experiments suggest that both phototropins interact of almost all extracellular physical stimuli in plants. related MOdifier (SUMO) regulates essential protein Ubiquitin Ligase Constitutive Photomorphogenesis with SUMO1, SUMO2 and SUMO3 in planta. The results The S-acylation state of RLKs changes upon ligand functions in eukaryotes. In plants, genetic studies 1 (COP1), while at the same time COP1 is a SUMO of Y2H analysis reveal that these interactions occur biding and we will discuss our findings in the context of have established a role for SUMOylation in plant substrate. In the dark and at high temperatures COP1 mainly through their N-terminal parts. Y2H analysis RLK signalling regulation. We will also detail our work development and environmental stress responses. relocalizes from the cytoplasm to nuclear bodies also indicates that phot1 interacts with MMS21, a on defining the dynamic S-acyl proteome to increase However, the molecular mechanisms through which (NBs), called photobodies. The general notion is SUMO E3 ligase. Phot2 shows a stronger interaction understanding of how this enigmatic modification SUMO regulates those biological processes are poorly that these photobodies signify sites of degradation with MMS21, than with SIZ1 SUMO E3 ligase. Both regulates membrane protein function. understood. Another key question that remains to be of COP1 substrates. Remarkably, we found that (i) phot1 and phot2 N-terminal parts are modified by answer is whether SUMOylation of protein targets COP1 co-localizes with SIZ1 in NBs. COP1 targeting SIZ1 and MMS21 when expressed in an Arabidopsis is only dependent on substrate accessibility or, in to these bodies does not depend on its SUMOylation sumoylation system reconstituted in bacteria. To addition, other regulatory mechanisms modulate the state, albeit COP1 and SUMO bodies strongly overlap. analyze the significance of phototropin sumoylation, spatiotemporal capacity of the plant to conjugate SUMO. We also found that (ii)mutations that disrupt SUMO two phototropin-controlled reactions: phototropism In the last years, our group has contributed to conjugation activity abrogate the formation of SUMO- in etiolated seedlings and chloroplast movements in highlight the complexity of the Arabidopsis SUMO bodies, but not COP1 bodies. Likewise, SUMO-body leaves have been characterized in mutants: sum1, sum2, system in terms of the number and the biochemical formation appears not to depend on the interaction sum3, sum5, siz1 and mms21. Chloroplast movements properties of its components. SUMO isoforms have between SIZ1 and COP1. We will present cell biology in Arabidopsis leaves are not altered after both light diverged to the extent of displaying biochemical and data on the functional overlap between COP1 and pulses and continuous light treatments. By contrast, biological differences. Other members, such as the SUMO bodies. the phototropic bending of seedlings is diminished in E1 activating enzyme and SUMO proteases, also play siz1 and mms21 mutant background upon very weak an important regulatory role conferring specificity to blue light exposure. This effect may be attributed to the system. These aspects and current advances in the modulation of phototropin1 activity. The analysis E1 regulation will be discussed in greater detail. of phototropin levels in mutants of the sumoylation pathway reveals no differences in bothArabidopsis seedlings and leaves regardless of light conditions. CELL SECTION SYMPOSIUM ABSTRACTS 20 CELL SECTION SYMPOSIUM ABSTRACTS 21

C S 17.1 3 N-TERMINAL ACETYLATION - the stability of the Nod-like immune receptor SNC1. C S 17.1 5 O-GLYCOSYLATION OF C S 17.1 6 GLYCATED PEPTIDES We propose that imprinting of the proteome by NatA A PREVALENT PROTEIN MODIFICATION NUCLEAR AND CYTOSOLIC PROTEINS TRIGGERS H2O2 SIGNALLING IN is an important, hormone-regulated switch for control IN PLANTS ARABIDOPSIS THALIANA THAT LIKES TO SURPRISE of abiotic and biotic stress responses.

MONDAY 11 DECEMBER 2017 17:00 MONDAY 11 DECEMBER 2017 18:00 MONDAY 11 DECEMBER 2017 18:15 MARKUS WIRTZ (HEIDELBERG UNIVERSITY, C S 17.1 4 PROTEIN LYSINE DORIS LUCYSHYN (UNIVERSITY OF NATURAL AMANDA K CHAPLIN (UNIVERSITY OF ESSEX, GERMANY), ERIC LINSTER (HEIDELBERG METHYLATION IN PLANTS: FROM RESOURCES AND LIFE SCIENCES VIENNA, UNITED KINGDOM), ULRIKE BECHTOLD UNIVERSITY, GERMANY), IWONA STEPHAN PROTEOME TO PHENOTYPE...THE QUEST AUSTRIA), BIRGIT WIMMER (UNIVERSITY (UNIVERSITY OF ESSEX, UNITED KINGDOM) (HEIDELBERG UNIVERSITY, GERMANY), PAVLINA FOR THE HOLY GRAIL OF NATURAL RESOURCES AND LIFE SCIENCES MIKLANKOVA (HEIDELBERG UNIVERSITY, VIENNA, AUSTRIA), EVA LIEBMINGER [email protected] GERMANY), MONIKA HUBER (HEIDELBERG (UNIVERSITY OF NATURAL RESOURCES AND LIFE MONDAY 11 DECEMBER 2017 17:30 Plants suffer stress in a multitude of ways. Reduced UNIVERSITY, GERMANY), WILLY BIENVENUT SCIENCES VIENNA, AUSTRIA), NICOLE NEUMAYER water availability, increased temperature and light (INSTITUTE FOR INTEGRATIVE BIOLOGY OF STÉPHANE RAVANEL (CEA, PLANT CELL (UNIVERSITY OF NATURAL RESOURCES AND LIFE THE CELL CNRS, FRANCE), THIERRY MEINNEL PHYSIOLOGY LABORATORY - GRENOBLE, FRANCE) SCIENCES VIENNA, AUSTRIA), ISABELLA ZANGL intensity are some of the challenges they may face. (INSTITUTE FOR INTEGRATIVE BIOLOGY OF (UNIVERSITY OF NATURAL RESOURCES AND LIFE Elucidating the mechanisms underpinning the THE CELL CNRS, FRANCE), CARMELA GIGLIONE [email protected] SCIENCES VIENNA, AUSTRIA) plants response during these conditions will lead to a significant improvement in their performance and (INSTITUTE FOR INTEGRATIVE BIOLOGY OF Protein methylation is a very diverse, important and [email protected] is thus of interest. One such response that may be THE CELL CNRS, FRANCE), RUEDIGER HELL widespread post-translational modification affecting (HEIDELBERG UNIVERSITY, GERMANY) employed by the plants under these stress conditions is many cellular processes in eukaryotes. Methylation O-Glycosylation of nuclear and cytosolic proteins the glycation of proteins. Glycation is a non-enzymatic occurs primarily on the side chain of lysine and arginine is a very common post-translational modification [email protected] reaction between sugars and proteins yielding the residues, playing structural roles and contributing to (PTM), contributing to the complexity in the formation of early and advanced glycation end N-terminal acetylation (NTA) is among the most the regulation of protein function. Lysine methylation function and regulation of proteins. In contrast products (AGEs). AGEs cross-link and have been shown common protein modifications in eukaryotes. Its has received considerable attention in the case of to other types of glycosylation, a single sugar to inhibit protein function in humans and are a major frequency increases with organismal complexity and histone proteins due to its role as a key regulator of residue - either N-acetylglucosamine (GlcNAc) or contributor in diabetes. AGEs also play essential roles in reaches up to 80% in the human cytosolic proteome. chromatin state and gene regulation. During the fucose - is attached to serine or threonine residues signalling cascades by switching on defence pathways In yeast NTA is tightly linked to ubiquitin-mediated last 15 years, lysine methylation of non-histone of a high number of very diverse proteins. O-GlcNAc through binding to specific receptors. These potentially proteasome degradation, but its significance in higher proteins emerged as a very common modification modification is well characterised in animals, where deleterious compounds are well characterised in eukaryotes is still enigmatic. NTA has been shown and has been extensively studied in yeast and it is essential for development and decisively involved animal systems but limited information is available to affect protein-protein interaction, subcellular animal cells. In plants, our knowledge in this field is in a range of signalling events, often affecting protein in plants. We have identified using a LCMS proteomics localization and stability of N-terminal a-helices much more fragmentary. Here, we review historical interactions and competing with other O-linked based approach the glycated proteome in Arabidopsis in a limited number of examples. Six N-terminal and recent advances in the identification of lysine PTMs. While animals carry only one O-GlcNAc- thaliana. These results revealed 165 target proteins acetyltransferases (NatA-NatF) catalyze the transfer methylproteins in photosynthetic organisms together transferase (OGT), plants have two structurally across various aged plants. To analyse the effect of the acetyl group from acetyl-CoA to the N-terminus with the characterization of the enzymes involved in related O-glycosyltransferases, competing for the of stress on glycation, high-light, heat and drought of cytosolic proteins in higher eukaryotes. Here, we the deposition of methyl marks. Also, we discuss the same targets: the O-GlcNAc transferase SECRET stressors have been applied and have revealed a characterise the plant NatA complex and reveal current knowledge and future challenges about the role AGENT (SEC) and the protein O-fucosyltransferase handful of unique peptides that become targeted evolutionary conservation of NatA biochemical of protein lysine methylation in regulating molecular SPINDLY (SPY) show high sequence homology, for glycation under these stressors. To determine properties within higher eukaryotes. Based on and cellular functions in plants. but their activity can have opposite effects on their whether glycated peptides can create a stress the identified substrate specificity, NatA targets target proteins. This mechanism of counteracting signalling response, glycated BSA peptides were used up to 40% of the cytosolic plant proteome. The O-glycosyltransferases seems to be specific for plants. in conjunction with roGFP (orp1) Arabidopsis plants combined application of quantitative proteomics, Its importance for plant development is apparent to monitor H O production. Glycated BSA peptides transcriptomics and metabolomics on NatA depleted from genetic analysis, as a double knockout of the 2 2 trigger a clear H O response compared with non- plants uncovers specific and essential functions two enzymes is embryonic lethal. However, clearly 2 2 glycated BSA peptides. We concluded that glycation of NatA for development, biosynthetic pathways more research is necessary to identify more targets and is an important mechanism in plants under stress. and stress responses. Hitherto, NTA was believed establish which cellular and developmental processes to be constitutive in eukaryotes. We show that NTA involve this modification, in order to understand the decreases significantly after drought stress in plants molecular mechanisms underlying O-glycosylation and identify the phytohormone abscisic acid as an in plants. So far also the techniques to study this efficient and prompt regulator of NatA abundance in type of glycosylation are limited. We are currently plants. Transgenic down-regulation of NatA promotes working on these questions using a combination the drought stress response program and results in of different approaches, including identification of strikingly drought resistant plants. In addition, NatA targets of SPY and SEC, as well as interacting proteins. controls the plant immune response by regulating Supported by the Austrian Academy of Sciences ÖAW and the Austrian Science Fund FWF. CELL SECTION SYMPOSIUM ABSTRACTS 22 CELL SECTION SYMPOSIUM ABSTRACTS 23

CS17.17 SUMO-SIM NETWORKS C S 17.1 8 TRANSCRIPTIONAL C S 17.1 9 AUXIN-PROGRAMMED C S 17.2 0 REGULATION OF PLANT/ REGULATE THE ASSEMBLY OF DYNAMIC REGULATION BY DYNAMIC UBIQUITYLATION AS A MASTER PATHOGEN INTERACTIONS BY THE PROTEIN COMPLEXES UBIQUITINATION SIGNAL INTEGRATION SYSTEM N-END RULE PATHWAY

TUESDAY 12 DECEMBER 2017 09:00 TUESDAY 12 DECEMBER 2017 10:15 TUESDAY 12 DECEMBER 2017 10:45 TUESDAY 12 DECEMBER 2017 11:15

RON T HAY (UNIVERSITY OF DUNDEE, STEVEN SPOEL (UNIVERSITY OF EDINBURGH, LUZ IRINA A CALDERON-VILLALOBOS EMMANUELLE GRACIET (MAYNOOTH UNIVERSITY, UNITED KINGDOM) UNITED KINGDOM) (LEIBNIZ INSTITUTE OF PLANT BIOCHEMISTRY IRELAND), REMI DE MARCHI (MAYNOOTH (IPB), GERMANY) UNIVERSITY, IRELAND), MAUD SOREL (MAYNOOTH [email protected] [email protected] UNIVERSITY, IRELAND), BRIAN MOONEY (MAYNOOTH UNIVERSITY, IRELAND), PATRICK [email protected] Small ubiquitin-related modifier (SUMO) conjugation Gene expression plays a pivotal role in the development RYAN (TRINITY COLLEGE , IRELAND), pathway is composed of SUMO paralogues, an E1 of eukaryotic cells and their response to the Auxin sensing is the archetype of a drug-like compound ISABELLE FUDAL (INRAAGROPARISTECH, activating enzyme, and the E2 conjugating enzyme environment. Failure to precisely program cellular that act as interfacial molecule prompting recognition FRANCE), JUERGEN KROYMANN (UNIVERSITÉ (UBC-9). The specificity and dynamic nature of this gene expression often has pathological or deleterious of degrons in protein targets, and stabilizing E3-target PARIS-SACLAY, FRANCE), STEPHAN modification is achieved by SUMO specific E3 ligases consequences. In plants, hormone-responsive associations. Hence, auxin triggers SCFTIR1/AFBs- POLLMANN (UNIVERSIDAD POLITÉCNICA DE and SUMO-specific isopeptidases. System wide transcriptional programs are controlled by nuclear MADRID, SPAIN), FRANK WELLMER (TRINITY AUX/IAAs interactions and auxin receptor assembly, proteomic analysis in a range of biological settings E3 ubiquitin ligases that function as both hormone COLLEGE DUBLIN, IRELAND), SUSANA RIVAS which ultimately results in AUX/IAA ubiquitylation has identified many SUMO proteins, although sites receptors and as transcription cofactors. The plant (LABORATOIRE DES INTERACTIONS PLANTES- and turnover. As there are 6 TIR1/AFBs and 29 AUX/ of attachment were unknown. We thus developed a immune hormone salicylic acid (SA) is perceived MICROORGANISMES, FRANCE) IAA proteins in Arabidopsis, distinct TIR1/AFB- specific peptide enrichment strategy that enables by a nuclear Cullin3-RING ubiquitin ligase (CRL3), AUX/IAA co-receptor pairs differentially perceive the identification of SUMO acceptor lysine residues resulting in the reprogramming of thousands of genes [email protected] auxin and constitute various auxin sensors in vivo. on a proteome-wide scale. Having validated this to prioritise immune responses over normal cellular We explore how the SCFTIR1 E3 ligase catalyses The ubiquitin-dependent N-end rule pathway relates approach in human cell lines we imported this system growth functions. SA-induced CRL3 ubiquitinates transfer of ubiquitin from the active site cysteine of the stability of a protein to the identity of its N-terminal into Caenorhabditis elegans to address the role of the indispensable transcription coactivator NPR1, an E2 to specific residues in AUX/IAAs, and ensures residue. Some N-terminal residues are stabilising and SUMO modification in meiosis. In oocyte meiosis, a resulting in its proteasome-mediated degradation. ubiquitin chain extension. Thus, we are investigating result in proteins with a long half-life, while other multi-protein ring complex (RC) localized between Surprisingly, turnover of NPR1 coactivator is necessary what confers AUX/IAA diversity and specificity, so-called destabilising residues may lead to rapid homologous chromosomes, promotes chromosome for the activation of its target genes, suggesting that namely AUX/IAA commitment and entry into the degradation of a protein when made N-terminal congression through the action of the chromokinesin transcription may require continuous delivery of degradation pathway. By using biochemical and (e.g. following protease cleavage). In the model KLP-19. While some RC components are known, the fresh NPR1 coactivator to gene promoters. To better biophysical approaches and the power of molecular plant Arabidopsis thaliana, the N-end rule pathway mechanism of RC assembly has remained obscure. We understand how ubiquitination orchestrates NPR1- population genetics and proteomics, we carefully has been shown to regulate various developmental show that SUMO E3 ligase GEI-17/PIAS is required for dependent transcriptional reprogramming, we used dissect auxin receptor formation, auxin binding, processes and controls flooding tolerance through KLP-19 recruitment to the RC and proteomic analysis genetic and biochemical approaches to investigate target ubiquitylation and degradation. We have the degradation of several Ethylene Response Factors identified KLP-19 as a SUMO substrate in vivo. In vitro the role of additional ubiquitin-modifying enzymes. also identified paramount features, including (ERFs). Using a pathogen susceptibility screen and analysis revealed that KLP-19 is efficiently sumoylated Here we present evidence that these enzymes control disordered hot spots, for target discrimination and Arabidopsis mutants for different components of the in a GEI-17 dependent manner, while GEI-17 undergoes transcriptional activity of NPR1 through dynamic processing. We pinpoint defining signatures for N-end rule pathway, we demonstrate that this protein extensive auto-sumoylation. GEI-17 and another RC processive ubiquitination and enable the proteasome auxin sensing and postulate structural features degradation pathway positively regulates plant component, the kinase BUB-1, contain functional to function as a transcriptional amplifier. in AUX/IAA proteins, which probably guide their defences against a wide range of bacterial and fungal SUMO Interaction Motifs (SIMs) allowing them to interactions and consequently downstream gene pathogens with different lifestyles. Transcriptomics recruit SUMO modified proteins, including KLP-19, regulation. The integrative approach advances our analyses further indicate that the arginylation into the RC. Thus dynamic SUMO modification and knowledge of writing and reading the ubiquitin code branch of the N-end rule pathway regulates the the presence of SIMs in RC components generate a on target proteins in plants, and provide mechanistical timing and potentiates the amplitude of the defence SUMO-SIM network that facilitates assembly of the insights into how hormonal signals are interpreted program against the model pathogen Pseudomonas RC. Our results highlight the importance of SUMO- in ubiquitylation and proteolysis ensuring fitness, syringae. Importantly, Arabidopsis mutant plants SIM networks in regulating the assembly of dynamic plasticity and survival. for the arginylation branch are also affected for their protein complexes. response to the immune hormone jasmonic acid and for the production of secondary metabolites with known functions in plant defence, thus suggesting a potential mechanism for a role of the N-end rule pathway in the regulation of plant/pathogen interactions. Finally, genetics approaches revealed the substrate proteins responsible for the susceptibility phenotype. CELL SECTION SYMPOSIUM ABSTRACTS 24 CELL SECTION SYMPOSIUM ABSTRACTS 25

C S 17.2 1 UBIQUITIN BINDING Funding: Austrian Science Fund (FWF) and C S 17.2 3 CONTROL OF PLANT IMMUNE C S 17.2 5 THE N-END RULE PATHWAY AND CONJUGATION IS IMPORTANT Austrian Academy of Sciences (ÖAW). FUNCTION THROUGH S-NITROSYLATION COUPLES PRC2 ACTIVITY TO OXYGEN FOR THE FUNCTION AND LOCALISATION AVAILABILITY IN FLOWERING PLANTS OF TOL PROTEINS TUESDAY 12 DECEMBER 2017 13:30 C S 17.2 2 PHOSPHORYLATION AND TUESDAY 12 DECEMBER 2017 14:30 GARY J LOAKE (UNIVERSITY OF EDINBURGH, TUESDAY 12 DECEMBER 2017 11:45 UBIQUITINATION REGULATE THE UNITED KINGDOM) Exo70B2 SUBUNIT OF THE EXOCYST DANIEL J GIBBS (UNIVERSITY OF BIRMINGHAM, BARBARA KORBEI (UNIVERSITY OF NATURAL UNITED KINGDOM), HANNAH TEDDS (UNIVERSITY - A CONVERGENCE POINT OF IMMUNE [email protected] RESOURCES AND LIFE SCIENCES VIENNA, OF BIRMINGHAM, UNITED KINGDOM), MARK SIGNALLING AND AUTOPHAGY BAILEY (UNIVERSITY OF BIRMINGHAM, UNITED AUSTRIA), LUCINDA DE-ARAÚJO (UNIVERSITY Changes in redox status are a conspicuous feature KINGDOM), MICHAEL HOLDSWORTH (UNIVERSITY OF NATURAL RESOURCES AND LIFE SCIENCES of immune responses in a variety of eukaryotes, VIENNA, AUSTRIA), LUCINDA DE-ARAÚJO TUESDAY 12 DECEMBER 2017 12:00 OF NOTTINGHAM, UNITED KINGDOM) but the associated signalling mechanisms are not (UNIVERSITY OF NATURAL RESOURCES AND well understood. In plants, attempted microbial LIFE SCIENCES VIENNA, AUSTRIA), JEANETTE MARCO TRUJILLO (LEIBNIZ INSTITUTE FOR [email protected] infection triggers the rapid synthesis of nitric oxide MOULINIER-ANZOLA (UNIVERSITY OF NATURAL PLANT BIOCHEMISTRY, GERMANY) RESOURCES AND LIFE SCIENCES VIENNA, (NO) and a parallel accumulation of reactive oxygen The polycomb repressive complex 2 (PRC2) [email protected] AUSTRIA), CHRISTINA ARTNER (INSTITUTE OF intermediates (ROIs). In this context, we are exploring controls epigenetic gene repression in eukaryotes. S-nitrosylation, the addition of an NO moiety to a Although many functions for PRC2 are known, SCIENCE AND TECHNOLOGY, AUSTRIA), LISA The exocyst is a conserved hetero-octameric complex protein cysteine thiol to form an S-nitrosothiol, which mechanisms regulating PRC2 specificity and JÖRG (UNIVERSITY OF NATURAL RESOURCES AND mediating early tethering during exocytosis. Its is emerging as a key regulator of the plant defence signal-responsiveness are poorly understood. In LIFE SCIENCES VIENNA, AUSTRIA) Exo70 subunit plays a critical role as a spatiotemporal response, controlling ROI synthesis, the accumulation the flowering plantArabidopsis thaliana, the PRC2 regulator by mediating numerous protein and lipid [email protected] of the immune activator, salicylic acid, hypersensitive subunit VERNALIZATION2 (VRN2) accumulates in interactions. However, a molecular understanding cell death and defence at the cell wall. cold temperatures, where it regulates the epigenetic To be able to respond quickly and accurately to of the exocyst function remains challenging. We memory of winter to coordinate flowering in the spring, changing environmental conditions plasma membrane show that Exo70B2, locates to the plasma membrane a process termed vernalization. A mechanism for (PM) protein abundance and localisation are under and transits through a BFA-sensitive compartment, this environmentally determined stabilisation has tight regulation. In higher plants, the endocytic reflecting its canonical function in secretion. We had C S 17.2 4 OXIDATIVE STRESS remained elusive. Here we show that the stability of adaptor protein family of the TOL proteins, which previously shown that Exo70B2 is ubiquitinated by the SIGNALING IN PLANTS. TOWARDS VRN2 is controlled by the Arg/N-end rule pathway, contain two conserved ubiquitin binding domains E3 ligase PUB22 and degraded during PAMP-triggered THE PROTEOME AND BEYOND a conserved division of the ubiquitin proteasome (UBDs), functions at the PM in the recognition immunity, potentially to dampen immune responses. system that targets proteins for degradation based of ubiquitinated cargo destined for degradation. We will show that treatment with the salicylic acid TUESDAY 12 DECEMBER 2017 14:00 on the nature of their N-terminus. This pathway was Ubiquitin receptors, containing UBDs, are frequently (SA) defence hormone analogue Benzothiadiazole FRANK VAN BREUSEGEM (VIB GHENT, BELGIUM) previously shown to coordinate oxygen and nitric subjected to a regulatory mechanism termed (BTH), or the immunogenic peptide flg22, induced oxide sensing in plants, through controlling the coupled monoubiquitination, whereby their own Exo70B2 transport into the vacuole via two ATG8- [email protected] stability of ERFVII transcription factors. Similarly ubiquitination affects their ability to bind to ubiquitin interacting motifs (AIMs). We also show that Exo70B2 to ERFVIIs, degradation of VRN2 is dependent on its in trans. We found a portion of endogenous TOL6 as well is phosphorylated near the AIMs by the mitogen- In plants, alterations of reactive oxygen species (ROS) Met-Cys-initiating N-terminus (N-degron), which as Venus-tagged reporter constructs of various TOLs activated protein Kinase 3 (MPK3) and mimicking levels cause fluctuations of the redox balance and links its stability to oxygen availability, and restricts to be ubiquitinated in plants. To assess the importance phosphorylation enhances ATG8 interaction. Finally, hence can affect many aspects of cellular physiology. its accumulation under normoxic (oxygen-replete) of ubiquitin binding as well as ubiquitination of the Exo70B2 phosphonull lines are hypersensitive to ROS levels are controlled by a diversified set of and non-vernalizing (warmer) conditions. We found TOL proteins, we constructed non functional-UBD BTH and displayed enhanced effector-triggered antioxidant systems that allow the maintenance of that vernalization induces a hypoxia-like state that containing as well as constitutively ubiquitinated TOL immunity (ETI). We propose a molecular mechanism, redox status. Perturbations of these ROS levels can facilitates VRN2 stabilisation and function, providing constructs. With these TOL constructs, we performed in which Exo70B2 phosphorylation may be required lead to transient or permanent changes in the redox a mechanism for its cold responsive accumulation in vitro ubiquitin binding studies and could successfully to control immune responses by synergistically status. This feature is exploited by plants in different and activity. Although PRC2s are widely conserved show a substantial decrease in ubiquitin binding. regulating the interaction with ATG8 and stress signalling mechanisms. Understanding how in eukaryotes, VRN2 orthologues in animals and early Accordingly, we designed in vivo TOL constructs to ubiquitination to divert Exo70B2 from the secretory plants sense ROS and transduce these stimuli into evolving plants lack Met-Cys N-degrons, prompting analyze the effect in plants, where we found a shift in into the autophagic pathway. downstream biological responses is still a major us to investigate how VRN2 was coopted to the N-end the subcellular localisation from the PM to the cytosol, challenge. Previous transcriptome-centered analyses, rule pathway during angiosperm evolution. Our when compared to the endogenous TOLs. Furthermore, provided us first insights in the regulatory networks phylogenetic and biochemical studies reveal that a these TOLs lost their ability to fully rescue a higher that govern the oxidative stress response. Now, latent internal gas-sensitive N-degron was exposed order mutant plant line with a very pleiotrophic tailoring various proteomics technologies allowed in VRN2 following gene-duplication and N-terminal phenotype. The localization and function of the us to assess oxidative stress dependent changes at truncation of an ancient orthologue, which facilitated TOLs is therefore potentially regulated by coupled the posttranslational level. These efforts will allow neofunctionalisation of PRC2 in flowering plants. mono ubiquitination thereby adding another level a better understanding of how cells interpret the to the fine-tuning in the degradation of PM proteins oxidative signals that arise from developmental cues and thus adaptation in higher plants. and stress conditions. CELL SECTION SYMPOSIUM ABSTRACTS 26 CELL SECTION SYMPOSIUM ABSTRACTS 27

C S 17.2 6 POST-TRANSLATIONAL in plants with enhanced endogenous levels of the show that the pathogen-inducible TRX superfamily C S 17.2 9 MONITORING MODIFICATION OF HISTONES: physiological NO donor S-nitrosoglutathione. Since member, Nucleoredoxin 1 (NRX1), was unable to PHOSPHORYLATION AND NITRIC OXIDE MODULATES perturbation of the methyl donor supply is supposed restore immunity in mutants that display excessive UBIQUITINATION IN PATTERN to affect DNA and histone methylation, the imprinting accumulation of free NO, but rescued the immune- RECOGNITION RECEPTOR SIGNALLING CHROMATIN STRUCTURE of histone H3 by methylation marks was quantified in compromised phenotype of mutants that exhibit these plants. Immunological detection of H3K9me2 elevated levels of GSNO. Accordingly, overexpression TUESDAY 12 DECEMBER 2017 16:30 TUESDAY 12 DECEMBER 2017 15:00 and a LC-MS profiling approach demonstrated of NRX1 partially restored gene expression programs EVA-ESTHER RUDOLF (HELMHOLTZ ZENTRUM independently a significant global increase in this induced by the immune hormone salicylic acid. Whilst FRANK MENKE (THE SAINSBURY LABORATORY, MÜNCHEN INSTITUTE OF BIOCHEMICAL PLANT modification. Taken together, our data imply a new role it is still unclear if NRX1 can act directly as a protein- UNITED KINGDOM) PATHOLOGY, GERMANY), ALEXANDRA AGEEVA- of NO in regulation of chromatin structure in plants. SNO reductase, collectively, these findings highlight KIEFERLE (HELMHOLTZ ZENTRUM MÜNCHEN that NRX1 and TRXh5 regulate distinct branches of [email protected] INSTITUTE OF BIOCHEMICAL PLANT PATHOLOGY, and hence provide novel specificity to protein-SNO GERMANY), ALEXANDER MENGEL (HELMHOLTZ C S 17.2 7 NUCLEOREDOXIN 1 signalling in plant immunity. Pattern recognition receptors (PRRs) play a key role ZENTRUM MÜNCHEN INSTITUTE OF BIOCHEMICAL (NRX1) SELECTIVELY RESCUES in the first line of defence in both plant and animal PLANT PATHOLOGY, GERMANY), IGNASI FORNE PLANT IMMUNITY innate immunity. PRR binding of their cognate (LUDWIG-MAXIMILIANS-UNIVERSITÄT MÜNCHEN C S 17.2 8 DEVELOPING MASS ligand triggers a signalling network that ultimately PROTEIN ANALYSIS UNIT, GERMANY), RÜDIGER SPECTROMETRY BASED PROTEOMIC results in an immune response. How activated PRR HELL (RUPRECHT-KARLS-UNIVERSITÄT TUESDAY 12 DECEMBER 2017 15:15 are connected to downstream defence activation has HEIDELBERG CENTRE FOR ORGANISMAL STUDIES, METHODS TO IDENTIFY AND QUANTIFY CAPILLA MATA-PEREZ (INSTITUTE OF MOLECULAR largely remained an open question, but it is evident GERMANY), AXEL IMHOF (LUDWIG-MAXIMILIANS- PROTEIN CARBONYLATION IN PLANTS PLANT SCIENCES, SCHOOL OF BIOLOGICAL that changes in phosphorylation play a major role UNIVERSITÄT MÜNCHEN PROTEIN ANALYSIS SCIENCES, UNIVERSITY OF EDINBURGH, UNITED and changes in ubiquitination play an emergent UNIT, GERMANY), MARKUS WIRTZ (RUPRECHT- TUESDAY 12 DECEMBER 2017 16:00 KINGDOM), SOPHIE KNEESHAW (INSTITUTE role. We have used quantitative phosphoproteomics KARLS-UNIVERSITÄT HEIDELBERG CENTRE FOR OF MOLECULAR PLANT SCIENCES, SCHOOL approaches (Benschop et al., 2007; Mithoe et al., 2012) ORGANISMAL STUDIES, GERMANY), JÖRG DURNER ALEX JONES (UNIVERSITY OF WARWICK, UNITED OF BIOLOGICAL SCIENCES, UNIVERSITY OF to identify key players in PRR signalling. Some of the (HELMHOLTZ ZENTRUM MÜNCHEN INSTITUTE OF KINGDOM), GEORGINA CHARLTON (UNIVERSITY EDINBURGH, UNITED KINGDOM), STEVEN H SPOEL BIOCHEMICAL PLANT PATHOLOGY, GERMANY), OF WARWICK, UNITED KINGDOM), JOHN SINCLAIR earliest changes in phosphorylation, immediately (INSTITUTE OF MOLECULAR PLANT SCIENCES, CHRISTIAN LINDERMAYR (HELMHOLTZ ZENTRUM (SYNGENTA, UNITED KINGDOM), PETER KILBY downstream of activated PRRs, were identified on SCHOOL OF BIOLOGICAL SCIENCES, UNIVERSITY MÜNCHEN INSTITUTE OF BIOCHEMICAL PLANT (SYNGENTA, UNITED KINGDOM) BIK1, RBOHD and MKKK7 (Kadota et al 2014; Mithoe OF EDINBURGH, UNITED KINGDOM) PATHOLOGY, GERMANY) et al 2016). Our initial analysis using a ubiquitin- [email protected] remnant enrichment approach suggests that key [email protected] [email protected] components of PRR signalling also rapidly become Both biotic and abiotic stresses result in the generation ubiquitinated. Using targeted proteomics we are now Post-translational modifications (PTM) are vital Cellular redox changes play important roles in of Reactive Oxygen Species (ROS) within cells. A ROS measuring temporal changes in both phosphorylation in epigenetic processes, because they allow a cell eukaryotic immune responses. Upon pathogen attack, burst plays a fundamental role in stress response and ubiquitination on components required in the to quickly reply to internal or external appeals. host cells produce large quantities of reactive oxygen signalling, but also damages proteins and lipids PRR signalling network. Ongoing work on in vivo Acetylation and methylation of lysine residues are and nitrogen species, of which the signal molecule through the uncontrolled action of free radicals. measurements of these post translation modification well studied PTMs that plays a key role in regulation nitric oxide (NO) plays particularly important roles. Protein carbonylation is an irreversible and harmful on PRR signalling components will be presented. of gene expression through histone modifications. Intracellular NO signals mainly by modifying cysteine oxidative protein modification. The identification of Several studies demonstrate the impotence of histone residues, thereby forming S-nitrosothiols (SNO). many protein modifications is well established; the deacetylases (HDACs) that remove an acetyl group SNO modifications have been shown to alter the main limitations being the abundance of modified from histones during plant development and biotic or activity, conformation, localisation and function of peptides in complex mixtures and the interpretation abiotic stress response. We demonstrated that nitric signalling proteins that harbour them. In plant cells, of peptide fragmentation patterns. The identification oxide (NO), an important plant signalling molecule, is excessive protein-SNO accumulation has been linked of carbonylated peptides has lagged behind other involved in the regulation of histone acetylation by to pathogenesis and impaired immunity, indicating methods, due to their low abundance and complex inhibiting HDACs activity. Genome-wide H3K9/14ac that cellular mechanisms to remove protein-SNO secondary modifications. Most methods to identify profiles in Arabidopsis seedlings were generated by are vital to cellular survival. It was recently reported carbonylation require enrichment and derivatisation. ChIP-sequencing and NO-dependent changes were that the evolutionary conserved oxidoreductase, We are evaluating the use of a classic carbonyl-reactive quantified thereby identifying genes which display Thioredoxin-h5 (TRXh5), plays a key role in directly compound, 2, 4-Dinitrophenylhydrazine compared putative NO-regulated histone acetylation. Functional removing protein-SNO during plant immunity. TRXh5 to aminoxyTamdem Mass Tags (ThermoScientific) classification of these genes revealed that many acts as a selective protein denitrosylase exhibiting and the enrichment of low abundance carbonylated of them are involved in the plant defence response preferential activity towards protein-SNO that are peptides from complex mixtures such as plant leaves. and the abiotic stress response. Moreover, we have formed from free NO over those generated by the evidence that NO is involved in regulation of histone NO donor S-nitrosoglutathione (GSNO). Thus, an methylation. Interestingly, the level of the methyl enzyme that directly reduces protein-SNO derived group donor S-adenosylmethionine is increased from GSNO has not yet been reported. Here we CELL SECTION SYMPOSIUM ABSTRACTS 28 CELL SECTION SYMPOSIUM ABSTRACTS 29

C S 17.3 0 ON-SITE INSPECTION C S 17.3 1 PROTEASOME-INDEPENDENT C S 17.3 2 THE DYNAMIC OF UBIQUITYLATION ROLES OF LYSINE63-LINKED PHOSPHOPROTEOME ALLOWS POLYUBIQUITIN CHAINS: INSIGHT IDENTIFYING NOVEL ABIOTIC TUESDAY 12 DECEMBER 2017 17:00 FROM SENSOR-BASED PROTEOMICS STRESS SIGNALLING COMPONENTS KATJA BAERENFALLER (SIAF, SWITZERLAND), SEBASTIAN GOMEZ PETERSEN (ETH ZURICH, TUESDAY 12 DECEMBER 2017 17:30 TUESDAY 12 DECEMBER 2017 17:45 SWITZERLAND), JULIA SVOZIL (ETH ZURICH, GREG VERT (INSTITUTE FOR INTEGRATIVE IVE DE SMET (VIB, BELGIUM), LAM DAI VU SWITZERLAND), PHILLIP IHMOR (ETH ZURICH, BIOLOGY OF THE CELL - CNRS, FRANCE) (VIB, BELGIUM), NATALIA NIKONOROVA (VIB, SWITZERLAND) BELGIUM), SHANSHUO ZHU (VIB, BELGIUM), [email protected] ANGELS DE LUIS BALAGUER (NORTH CAROLINA [email protected] STATE UNIVERSITY, UNITED STATES), ROSS Plants have evolved sophisticated strategies to SOZZANI (NORTH CAROLINA STATE UNIVERSITY, Protein degradation and turnover are important constantly monitor and respond to ever changing UNITED STATES), BRIGITTE VAN DE COTTE cellular processes that ensure that at any time the environmental conditions. This is achieved in part (VIB, BELGIUM), LISA VAN DEN BROECK (VIB, adequate quantity of proteins are present in the proper by sophisticated regulatory mechanisms using the BELGIUM), DIRK INZÉ (VIB, BELGIUM), KRIS location and in the required activity state. To get a post-translational modification ubiquitin. Ubiquitin GEVAERT (VIB, BELGIUM) better understanding for the role of protein turnover modifications exist under many different forms in protein homeostasis and in the response to internal in eukaryotic cells. Except for lysine-48-linked [email protected] or external cues we had enriched for ubiquitylated polyubiquitin chains, which mediate proteasome- proteins in leaf mesophyll, epidermal and vascular To fully understand plant growth and development dependent degradation, our knowledge about all other tissues and found that almost all proteins in the (also under environmental stress conditions), we subtypes of post-translational modifications involving aliphatic glucosinolate biosynthesis pathway were need to identify novel signalling components and ubiquitin is still scarce. Over the past few years, my lab ubiquitylated in vasculature. Following this up we require insight in the underlying network. Abiotic has been deconstructing the networks and roles of the investigated whether constant protein degradation stress conditions, such as drought and temperature, second most abundant and yet poorly-characterised might serve to keep defence protein levels low as trigger signalling cascades in the plant. However, ubiquitin form : the lysine(K)-63 polyubiquitin chains. long as they are not required. As changing protein very little is known about the early signalling steps, We have initiated the identification of the machinery stability is a rapid post-transcriptional mechanism immediately following stress perception. In this driving the formation of K63 polyubiquitin chains and to change protein levels, we assessed changes in context, the reversible post-translational modification have isolated the Arabidopsis proteome specifically transcription, translation and protein levels, as well as phosphorylation impacts on all aspects of cellular modified with K63-linked chains using a combination in protein turnover using a dynamic SILAC approach in signalling and activity. Here, I will present data on of interactome and K63 polyubiquitin sensor-based response to treatment with flagellin 22. Interestingly, how our phosphoproteomics workflow allowed proteomics proteomics. This offers a unique insight we observed that upregulation at transcriptional and exposing novel factors in osmotic and temperature into the biological functions of K63 polyubiquitination translational level was sometimes counteracted stress signalling. I will show our progress on associated in protein translation, metabolism, trafficking by increased protein turnover, leading to constant loss-of-function phenotypes (on the developmental processes between cellular compartments, etc. We protein levels. As protein polyubiquitylation is the and molecular level), and touch upon the functional have notably characterized the prominent role of main mechanism to target proteins to degradation relevance of specific phosphorylation signatures. K63 polyubiquitination in plant cell surface protein by the ubiquitin 26S-proteasome system (UPS), we Furthermore, our temporal data set following a endocytosis and its contribution to plant growth were interested in determining the sites of ubiquitin temperature trigger allowed reverse engineering a and stress responses using the BRI1 brassinosteroid attachment. After we got an unpleasant surprise static network in silico, connecting regulatory kinases receptor and the IRT1 metal transporter. We have applying a commonly used search strategy to identify with their potential substrates. uncovered that IRT1 is differentially ubiquitinated the ubiquitin footprint, we inspected its fragmentation in response to changes in environmental conditions properties in more detail and keep on optimising the to regulate its partitioning in the cell. We have also strategy to enrich for peptides with ubiquitin footprint. demonstrated that K63 polyubiquitination of IRT1 is sequentially acquired during endocytosis, by extension of monoubiquitin moieties attached to IRT1 at the cell surface into K63-linked polyubiquitin chains in endosomes, via a cascade of E3 ubiquitin ligases. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 30 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 31

POSTER SESSION C S 17.3 5 PROTEIN S-PALMITOYLATION C S 17.3 6 MITOGEN ACTIVATED PROTEIN REGULATES INVASION AND APICAL KINASES (MAPKS) ACTIVATION POST MONDAY 11 DECEMBER ORGANELLE SECRETION IN HUMAN EFFECTOR RECOGNITION IN TOMATO MALARIA PARASITE, PLASMODIUM FALCIPARUM MONDAY 11 DECEMBER 2017 ARSHEED H SHEIKH (SCHOOL OF LIFE SCIENCES, MONDAY 11 DECEMBER 2017 UNIVERSITY OF WARWICK, UNITED KINGDOM), MANSOOR AZEEM SIDDIQUI (INTERNATIONAL VARDIS NTOUKAKIS (SCHOOL OF LIFE SCIENCES, C S 17.3 3 POST-TRANSLATIONAL C S 17.3 4 OsSGT1 REGULATES ROOT CENTRE FOR GENETIC ENGINEERING AND UNIVERSITY OF WARWICK, UNITED KINGDOM) BIO-TECHNOLOGY, INDIA), SHAILJA SINGH MODIFICATIONS REGULATE STARCH DEVELOPMENT AND GROWTH IN RICE [email protected] BRANCHING ENZYME 2.2 IN SINGH (JAWAHARLAL NEHRU UNIVERSITY, ARABIDOPSIS INDIA), PAWAN MALHOTRA (INTERNATIONAL The major virulence strategy of the phytopathogenic MONDAY 11 DECEMBER 2017 CENTRE FOR GENETIC ENGINEERING AND bacteria Pseudomonas syringae pv. tomato DC3000 BIO-TECHNOLOGY, INDIA), CHETAN E CHITNIS is to secrete effector proteins into the tomato cells to MONDAY 11 DECEMBER 2017 YANG DO CHOI (SEOUL NATIONAL UNIVERSITY, (INTERNATIONAL CENTRE FOR GENETIC target the immune machinery. Effectors like AvrPto KOREA (SOUTH)), TAE YOUNG UM (SEOUL ENGINEERING AND BIO-TECHNOLOGY, INDIA) GREGORY J MACNEILL (UNIVERSITY OF NATIONAL UNIVERSITY, KOREA (SOUTH)), and AvrPtoB are recognised by intracellular effector- GUELPH, CANADA), IAN J TETLOW (UNIVERSITY GEUPIL JANG (SEOUL NATIONAL UNIVERSITY, [email protected] recognition complex composed of the NBLRR protein OF GUELPH, CANADA), MICHAEL J EMES KOREA (SOUTH)) Prf and the Pto kinase. Following P+1 loop disruption Protein S-palmitoylatiom is the only reversible post (UNIVERSITY OF GUELPH, CANADA) and transphosphorylation the Pto/Prf complex translational lipid modification known in eukaryotic [email protected] dissociate leading to downstream signalling through [email protected] cells. The recently published global palmitome mitogen-activated protein kinases (MAPKs). Hence, Targeted degradation of protein is mediated by SCF for malaria parasite shows that over 400 proteins Starch is an important, osmotically inert carbon store the Pto/Prf complex is a sophisticated molecular trap complex composed of SKP1-Cullin-F-box protein. are S-palmitoylated in malaria parasite making in higher plants and a major component of the human for effectors and provides an excellent model to study Suppressor of G2 allele ofskp1, SGT1, is an E3 ligase it one of the most abundant post translational diet. Transient starch is produced and degraded in the mechanism of MAPKs activation. In the current complex-binding protein. It has been shown to be modification after phosphorylation.Inhibition of chloroplasts over the diurnal cycle. Biosynthesis occurs study we sought to investigate the mechanism of involved in plant development and immunity. Here protein S-palmitoylation in parasite has been known through the coordinated activity of multiple classes of MAPKs activation post Pto/Prf recognition of AvrPto/ we reports results of the functional study forOsSGT1in to inhibit red blood cell invasion but little is known enzymes. Starch synthases polymerize ADP-glucose AvrPtoB effectors. We identify 14-3-3 proteins as part of rice. It is strongly expressed in roots than in other about the possible mechanisms. Here we propose into α-glucan chains, while starch branching enzymes the Pto/Prf resistance complex acting as regulators of tissues such as shoot base and leaves. The root-specific that S-palmitoylation is necessary for microneme (SBE) introduce branch points to the growing glucan, MAPKs activation. 14-3-3 proteins could act as a bridge expression pattern of OsSGT1became decreased along release and invasion related signalling in malaria and debranching enzymes modify glucan architecture. for signal transduction from activated Pto/Prf complex age, indicating that is expressed in young roots at the parasite, Plasmodium falciparum. Inhibition of DHHC SBEs form phosphorylation-dependent complexes with to downstream MAPK cascade in ETI responses. higher activity of cell division. Root tips including palmitoyl acyl transferases or depalmitoylases by other starch biosynthetic enzymes. Two functional apical meristems showed higher enrichment of small molecule inhibitors affects the parasite’s ability isoforms of SBE exist in Arabidopsis, of which OsSGT1transcripts than upper part, suggesting to invade red blood cells by affecting vesicle (apical SBE2.2 accounts for most of the measurable activity. that is involved in root growth.OsSGT1expression in organelles) release or exocytosis in the parasite. Recombinant SBE2.2 can be phosphorylated by soluble roots was also regulated by exogenous treatment of plastid extracts on residues Ser290 and Ser301. A putative cytokinin which play a pivotal role in root development. protein-protein interaction domain, conserved across Cytokinin increased OsSGT1 expression in dosage- all class II SBEs, has also been identified. Site-directed dependent manner, suggesting its potential role in root mutagenesis is being used to alter this conserved growth in downstream of cytokinin. To understand the domain, Ser290 and Ser301 , and a C-terminal Cys residue role ofOsSGT1in rice root development, we generated to investigate their importance in catalysis and the root-specifically overexpressing transgenic rice (pSR3- formation of heteromeric complexes in vitro. The in vivo OsSGT1) and RNA interference rice (RNAi-OsSGT1). relevance of these post-translational modifications is Overexpression of OsSGT1 induced the distinct root being investigated by functional complementation morphology. It developed longer and large number of of Arabidopsis sbe null lines with wt and mutated roots suggesting that OsSGT1expression is positively SBE2.2. Effects on starch biosynthesis and structure correlated with root development. Agronomic trait will be determined. This research is significant for its analysis of these transgenic plants showed increase potential applications to crop production and targeted rice productivity as well as root growth. This indicates manipulation of starch structure. thatOsSGT1is involved in the regulation of rice root development and growth. Target proteins regulated by the OsSGT1 is also discussed. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 32 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 33

C S 17.3 7 UNRAVELLING C S 17.3 8 INTERPLAY BETWEEN C S 17.3 9 IMPAIRED PROTEASOME C S 17.4 0 ARABIDOPSIS PHOSPHORYLATION-MEDIATED PHOSPHORYLATION AND ACETYLATION FUNCTION IN ARABIDOPSIS RAD23ABCD DEUBIQUITINASE OTU5 IS INVOLVED SIGNALLING IN PLANTS AT HIGH IN REGULATING RPS4/RRS1 IMMUNE MUTANT ALTERS AUXIN HOMEOSTASIS IN FLOWERING BY REGULATING MAJOR AMBIENT TEMPERATURE RECEPTOR PAIR REPRESSORS FLC/MAF4/MAF5 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MARITA ANGGARANI (INSTITUTE OF PLANT LAM DAI VU (VIB-UGENT CENTER FOR PLANT HAILONG GUO (THE SAINSBURY LABORATORY, MOLECULAR BIOLOGY, ACADEMIA SINICA, RAM NIVAS AHIRWAR (INSTITUTE OF PLANT SYSTEMS BIOLOGY, BELGIUM), MARIA ANGELS UNITED KINGDOM), YAN MA (THE SAINSBURY TAIWAN), YA-LING LIN (INSTITUTE OF PLANT MOLECULAR BIOLOGY, ACADEMIA SINICA, DE LUIS BALAGUER (PLANT AND MICROBIAL LABORATORY, UNITED KINGDOM), ZANE DUXBURY MOLECULAR BIOLOGY, ACADEMIA SINICA, TAIWAN), RAMALINGAM RADJACOMMARE BIOLOGY DEPARTMENT NORTH CAROLINA (THE SAINSBURY LABORATORY, UNITED TAIWAN), HONGYONG FU (INSTITUTE OF PLANT (INSTITUTE OF PLANT MOLECULAR BIOLOGY, STATE UNIVERSITY, UNITED STATES), INGE KINGDOM), JAN SKLENAR (THE SAINSBURY MOLECULAR BIOLOGY, ACADEMIA SINICA, ACADEMIA SINICA, TAIWAN), HONGYONG FU VERSTRAETEN (INSTITUTE OF SCIENCE AND LABORATORY, UNITED KINGDOM), FRANK TAIWAN) (INSTITUTE OF PLANT MOLECULAR BIOLOGY, TECHNOLOGY, AUSTRIA), ROSANGELA SOZZANI MENKE (THE SAINSBURY LABORATORY, UNITED ACADEMIA SINICA, TAIWAN) (PLANT AND MICROBIAL BIOLOGY DEPARTMENT KINGDOM), JONATHAN D. G. JONES (THE [email protected] NORTH CAROLINA STATE UNIVERSITY, UNITED SAINSBURY LABORATORY, UNITED KINGDOM) [email protected] STATES), KRIS GEVAERT (VIB-UGENT CENTER Ubiquitylated substrate recognition during ubiquitin/ The reversible ubiquitylation reaction is catalysed by FOR MEDICAL BIOTECHNOLOGY, BELGIUM), [email protected] proteasome-mediated proteolysis (UPP) is mediated different classes of deubiquitinases (DUBs), including IVE DE SMET (VIB-UGENT CENTER FOR PLANT directly by the proteasome subunits RPN10 and RPN13 Pathogens secrete effector proteins into plant cells ovarian tumor domain (OTU)-containing DUBs. Based SYSTEMS BIOLOGY, BELGIUM) and indirectly by ubiquitin-like (UBL) and ubiqutin- to promote disease. In turn, plants evolved disease on distinct phylogeny, substrate binding, cleavage associated (UBA) proteins such as RAD23, DDI1 and resistance genes (R genes) that confer specific recognition specificities, and mutant phenotypes suggest the [email protected] DSK2. How the ubiquitylated substrate distinctly of pathogen effectors and activate a strong defence twelve Arabidopsis thaliana OTU deubiquitinases targeted to proteasome remains unclear. It has been High temperature has numerous effects on plant response known as effector-triggered immunity (ETI), participate in different functions. The null otu5-1 reported that RAD23 quadruple knock out mutant growth and development. Our knowledge on thermal which includes rapid transcriptional reprogramming displayed pleiotropic phenotypes including early is lethal and RAD23B is more important within the sensing and response mechanisms in plants has and programmed cell death at sites of infection. Most flowering, reduced organ size, plant height and reduced family. However, we are able to obtain the quadruple been increasing in the past years, mostly through plant R genes cloned to date encode immune receptors ovule numbers. Transcriptomics analyses indicate mutant thereof valuable for further functional genetics and by focusing on transcriptional changes called NLRs, with a conserved nucleotide-binding downregulation of major flowering repressorsFLC , characterisation. We found the phenotypes of rad23b-1 and associated networks. However, many missing (NB) domain and a C-terminal leucine-rich repeat and MAF4-5 is responsible for otu5-1 early flowering. mutant are not like the previously described. The links in the thermal signalling cascades are likely (LRR) domain. The adjacent, divergently transcribed, Nuclear fractionation, transient GFP expressions in quadruple mutant plants exhibited shorter root length, governed by various post-translational modifications. Arabidopsis Resistance to Ralstonia Solanacearum 1 protoplast and MNase treatment of chromatin revealed abnormal male and female gamete. The rad23abcd Here, I will report our latest findings on early (RRS1) and Resistance to Pseudomonas Syringae 4 (RPS4) that OTU5 is enriched in nucleus and associated with mutant has larger cell size in both epidermal and changes in protein phosphorylation in the dicot genes encode TIR-NLR proteins that function together chromatin. The qChIP analyses on FLC and MAF4- mesophyll cells of cotyledon which is the signature of Arabidopsis thaliana and the monocot Triticum to recognize two bacterial effectors, PopP2, an acetyl- 5 revealed reduction of activation histone mark proteasomal mutants. IAA-Asp increased and IAA- aestivumupon increasing ambient temperature. Starting transferase from Ralstonia solanacearum and AvrRps4, H3K36me3 and increment of repression histone Glu decreased in rad23abcd as compared to wild type, from a quantitative phosphoproteome, I identified a coil-coiled protein from Pseudomonas syringaepv.pisi. marks H3K27me3/H3K9me2 and H2Bub1 in otu5-1 while no alteration observed on the IAA and oxIAA thermoresponsive phosphoproteins, referred to as The RRS1-R allele in Arabidopsis accessions Nd-1 and indicate its involvement in transcriptional regulation level. IAA-Asp and IAA-Glu synthesis were regulated TOTORO/TARGET OF TEMPERATURE (TOT) candidates. Ws-2 confers AvrRps4 and PopP2 recognition, whereas on FLC and MAF4-5. qChIP results confirmed the OTU5 by GH3s genes, governed by the ARFs and AUX/IAA- The dynamic changes in phosphorylation status of TOTs Col-0 allele of RRS1 (RRS1-S) confers AvrRps4, but not association and its regulatory function on FLC, and targeted by proteasome. The qPCR analysis indicated at different stages of the response revealed potential PopP2, recognition. We previously reported that AvrRps4 MAF4-5. Catalytically inactive OTU5 was unable to alteration of these gene expressions in the rad23abcd networks of interplaying protein kinases, phosphatases interacts with, and PopP2 acetylates, the RRS1 WRKY compliment the defective growth phenotypes and compared to wild type. The rad23abcd mutant also has and their targets. These are linked to diverse cellular domain, resulting in activation of the RPS4/RRS1 early flowering ofotu5-1 , indicating the importance ABA and glucose sensitivity during early germination processes, providing us an entry point to gain mechanistic complex and subsequent defence activation. Here we of enzymatic function of OTU5. Size-exclusion stage and sensitive to UV-C treatment. This data insight into the regulation of distinct pathways by show that WRKY domain and its neighboring domain chromatography indicated OTU5 likely to function supports our previous finding that there is no substrate high temperature and the integration of those various DOM6 of RRS1-R, but not RRS1-S, is phosphorylated in large complex. Interestingly, otu5/arp6-/- double specificity for the ubiquitylated subtrates targeted to signals in a global response. I will also present data on the in vivo. Multiple phosphorylated residues of RRS1-R mutant shows synergistic phenotypes with severe the proteasome. In addition, we provide evidence that functional characterisation of some central regulators were identified using immunoprecipitation and mass developmental defects including seed abortion, curly the phenotypes observed in the rad23abcd mutant, of thermomorphogenesis in plants. For this, I focus spectrometry (IP-MS). Among those phosphosites, we leaves, and short statured plants. The ChIP results and likely for other proteasomal mutants, were caused on temperature-triggered growth responses, such as found that phosphorylation of RRS1-R at Ser 1296 is did not show alteration of H2A.Z at FLC, MAF4 and by Aux/IAA impaired degradation resulting in auxin hypocotyl elongation and upward bending of petioles, essential to PopP2, but not AvrRps4, recognition. Further MAF5 between otu5-1 and wild type Col-0, suggested homeostasis alteration. and downstream molecular and biochemical responses in studies are needed to dissect the molecular basis of OTU5 might function in different pathway. OTU5- loss-of-function lines. Further functional characterisation phosphorylation of RRS1 and to address the coordinated associated proteins and the underlying mechanism will be supported by protein-protein interaction studies as regulation between phosphorylation and acetylation in need to be elucidated by isolating complex and further well as in vitro and in vivo biochemical assays. mediating defence activation. characterisation. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 34 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 35

assess the variation of putative PTMs along the day. C S 17.4 1 COMBINATORIAL CS17.42 IDENTIFICATION OF C S 17.4 3 ON THE QUEST FOR HOST MEMBRANE PROTEINS THAT POSTTRANSLATIONAL MODIFICATIONS Dephosphorylation assays, followed by LC-MS/MS TRANSCRIPTIONAL REGULATION analyses, are being conducted to validate new PTMs. OF THE PLANT DEFENCE RESPONSE ARE INVOLVED IN PLANT-APHID GOVERNING PHOSPHOENOLPYRUVATE These results are the first step into the characterisation INTERACTIONS CARBOXYLASE LIFE CYCLE of the regulatory mechanisms modulating PEPC MONDAY 11 DECEMBER 2017 activity and stability. This characterisation will MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 establish the basis to uncover regulators behind the C4- MAURA DI MARTINO (UNIVERSITY OF WARWICK, metabolic pathways, which are still mostly unknown. JASMINE PHAM (THE JAMES HUTTON INSTITUTE, INÊS M LUÍS (IINSTITUTO DE TECNOLOGIA UNITED KINGDOM), KATHERINE DENBY (UNIVERSITY OF YORK, UNITED KINGDOM), UNITED KINGDOM), PATRICIA A RODRIGUEZ QUIMICA E BIOIOGICA ANTONIO XAVIER - ALEX JONES (UNIVERSITY OF WARWICK, UNITED (THE JAMES HUTTON INSTITUTE, UNITED UNIVERSIDADE NOVA DE LISBOA (ITQB-UNL), KINGDOM), EMILY BREEZE (UNIVERSITY OF KINGDOM), JORUNN I B BOS (UNIVERSITY OF PORTUGAL), BRUNO M ALEXANDRE (INSTITUTO C S 17.4 4 TRANSCRIPTOMIC PROFILING WARWICK, UNITED KINGDOM) DUNDEE AT THE JAMES HUTTON INSTITUTE, DE BIOLOGIA EXPERIMENTAL E TECNOLÓGICA UNITED KINGDOM) (IBET), PORTUGAL), VERA M MENDES (CENTRO OF CAPSICUM ANNUUM IN RESPONSE TO HIGH-INTENSITY UV IRRADIATION [email protected] DE NEUROCIÊNCIAS E BIOLOGIA CELULAR - [email protected] UNIVERSIDADE DE COIMBRA (CNC), PORTUGAL), REVEALS STRESS DEFENCE SIGNALLING Transcriptional reprogramming plays a significant NELSON J M SAIBO (INSTITUTO DE TECNOLOGIA role in the defence of plants against pathogen Aphids are agriculturally important phloem-feeding QUÍMICA E BIOLÓGICA ANTÓNIO XAVIER - MONDAY 11 DECEMBER 2017 infection. This defence response involves a complex pests which cause loss in many crops worldwide UNIVERSIDADE NOVA DE LISBOA (ITQB-UNL), and highly sophisticated regulatory circuitry in through damage caused by feeding, and by acting as PORTUGAL), M MARGARIDA OLIVEIRA (INSTITUTO LUIS A LIGHTBOURN (LIGHTBOURN RESEARCH INSTITUTE, MEXICO) which transcription factors (TFs) play a key role in vectors for transmission of plant viruses. These insects DE TECNOLOGIA QUÍMICA E BIOLÓGICA ANTÓNIO determining the specificity of the response to different use specialised mouthparts (stylets) to puncture and XAVIER - UNIVERSIDADE NOVA DE LISBOA [email protected] pathogens. We have obtained high-resolution temporal probe leaf tissue in search of the phloem, from which (ITQB-UNL), PORTUGAL), BRUNO MANADAS transcriptome data following biotic and abiotic they feed. (CENTRO DE NEUROCIÊNCIAS E BIOLOGIA Ultraviolet (UV) radiation augmentation can restrain stress treatments in Arabidopsis, and have generated As the aphid probes the leaf tissue, a gel saliva CELULAR - UNIVERSIDADE DE COIMBRA (CNC), growth of plants, including some important crops, regulatory network models of the TF interactions is secreted that forms a protective sheath around PORTUGAL), ISABEL A ABREU (INSTITUTO DE resulting in severe reduction in yield. This stress will TECNOLOGIA QUÍMICA E BIOLÓGICA ANTÓNIO underlying these responses. Such models predict the stylet. Staining of the gel saliva coupled with increase in the near future because of global climate XAVIER - UNIVERSIDADE NOVA DE LISBOA widespread combinatorial transcriptional regulation microscopy reveals the stylet path, showing change, according to reports from the Intergovernmental (ITQB-UNL), PORTUGAL)). of many known defence genes and pathways, providing extracellular movement through the tissue with Panel of Climate Change. Therefore, understanding UV a mechanism for generating complex transcriptional probe sites in the leaf cells along this path. In irradiations stress responses is now thought to be one [email protected] profiles, and thus fine-tuning the plant’s response. addition, watery saliva is also produced, which of the most important topics in plant science. However, Combinatorial regulation can also occur by variations contains effector proteins involved in manipulating C4-plants possess a more efficient photosynthetic UV-B stress signalling mechanisms in plants including in the composition of multi-subunit TFs. NF-Y TFs host cellular processes to aid infestation. system, mainly due to its ability to concentrate CO2 Capsicum annuum remain poorly understood. Molecular directly bind CCAAT boxes in target gene promoters Given the close proximity of the stylet to the around RuBisCO. A key player in this CO2 -concentrating biological analyses have allowed us to draw a picture as trimers of A, B and C subunits, and can act as plant cell surface, the secretion of effectors, and mechanism is the enzyme phosphoenolpyruvate of UV stress responses in plants, and determination positive or negative regulators of transcription. In the role of membrane proteins in plant defences, carboxylase (PEPC). PEPC uses the solubilised of the transcriptome has had a significant impact Arabidopsis a multi-gene family encodes each we aim to identify membrane proteins that are atmospheric CO2 to carboxylate phosphoenolpyruvate, on this research field. Therefore, the purpose of this subunit of the complex and many of these subunits involved in immunity or susceptibility towards aphid producing oxaloacetate that will be the first carrier in work was to explore the transcriptome dynamics of change in expression during plant stress responses. A infestation. To achieve this, we have enriched for the CO2 -concentrating mechanism. In C4-leaves, PEPC Capsicum plants in response to UV-B stress. We used a putative trimer (NF-YA2, NF-YB2, NF-YC2) has been membrane proteins from whole protein extracts of is a very abundant protein and its total amount varies RNA-sequencing method to perform gene-expression identified. We have shown that NF-YA2 expression Arabidopsis rosette and flowering tissue, with and little along the photoperiod. Thus, PEPC has to be tightly profiling of the transcripts under UV-B treatment. The levels determine accumulation of JA and that the without aphid infestation. Mass spectrometry and regulated to address the different carbon fixation needs radiation promoted the acclimation of Capsicum to UV nf-ya2 mutant displays significantly increased protein quantification (using MaxQuant and Perseus along the day. Posttranslational modifications (PTMs), by regulating the expression of genes with functions in susceptibility to Botrytis cinerea. Furthermore, BiFC software) was used to identify proteins that were up- or frequently, tune protein activity and/or stability. In UV protection and also by inducing the accumulation of assays in N. benthamiana revealed that NF-YB2 and down- regulated upon aphid infestation. To confirm PEPC, it is described that the phosphorylation of a serine phenolic compounds. Furthermore, most representative NF-YC2 are able to heterodimerise in planta, and this the importance of these proteins in plant-aphid residue at the N-terminal is important to diminish its transcripts related to biological pathways, including interaction was confirmed in Arabidopsis expressing interactions, Arabidopsis knockout mutants of these allosteric inhibition by malate. However, C4-plants that antioxidant enzymes, G proteins, primary and secondary tagged NF-YC2. We are now investigating whether this proteins will be tested for resistance/susceptibility are unable to phosphorylate this serine residue display metabolism, and transcription factors. Interestingly, NF-YB2/C2 dimer binds the NF-YA2 subunit, and, if so, to aphid infestation. From this work, we hope to normal photosynthetic capacity. This suggests that some of the genes involved in secondary metabolism. the regulatory function of the resulting NF-Y trimer characterise the membrane proteins and the cellular PTMs regulating PEPC are not yet described. To discover Transcriptome profiling highlights possible signalling during defence against B.cinerea. processes involved in the plant-aphid interaction. novel PEPC PTMs we collected leaves from maize, a C4- pathways and molecules for future research. These plant, during the photoperiod. We used an LC-MS/MS- results opened up ways of exploring the molecular based approach to analyse maize leaves proteome and mechanisms underlying the effects of UV-B irradiation on identify putative-phosphorylated and -ubiquitinated Capsicum and have great implications for further studies. residues. SWATH-MS analyses were performed to CELL SECTION SYMPOSIUM POSTER ABSTRACTS 36 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 37

C S 17.4 5 PP2A-B’γ CONTROLS capacity of leaf cells. Our results highlight a key role C S 17.47 DYNAMIC UBIQUITINATION C S 17.4 8 UNDERSTANDING THE ROLE METHYLATION OF INDOLE for PP2A-B’γ in controlling cross-communicating DETERMINES NPR1 TRANSCRIPTIONAL OF NITRATE REDUCTASES NIA1 AND metabolic cycles in methionine metabolism, which has GLUCOSINOLATES AND MODULATES a significant impact on plant resistance to biotic stress. COACTIVATOR ACTIVITY NIA2 UNDER ABIOTIC STRESSES METHIONINE METABOLISM IN ARABIDOPSIS MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 CORRELATION BETWEEN MONDAY 11 DECEMBER 2017 C S 17.4 6 MICHAEL J SKELLY (UNIVERSITY OF EDINBURGH, JOANNA LANDYMORE (UNIVERSITY OF SHEFFIELD, NPH3 PHOSPHORYLATION STATUS, UNITED KINGDOM), JAMES J FURNISS UNITED KINGDOM), JULIE E GRAY (UNIVERSITY SARA ALEGRE GARCÍA (UNIVERSITY OF TURKU, LOCALISATION AND PHOTOTROPIC (UNIVERSITY OF EDINBURGH, UNITED KINGDOM), OF SHEFFIELD, UNITED KINGDOM), MICHAEL J FINLAND), MOONA RAHIKAINEN (UNIVERSITY ENHANCEMENT HEATHER L GREY (UNIVERSITY OF EDINBURGH, HOLDSWORTH (UNIVERSITY OF NOTTINGHAM, OF TURKU, FINLAND), ANDREA TOTTRA UNITED KINGDOM), KA-WING WONG (UNIVERSITY UNITED KINGDOM), ANGELA HODGE (UNIVERSITY OF EDINBURGH, UNITED KINGDOM), STEVEN H OF YORK, UNITED KINGDOM) (UNIVERSITY OF TURKU, FINLAND), JESÚS MONDAY 11 DECEMBER 2017 PASCUAL (UNIVERSITY OF TURKU, FINLAND), SPOEL (UNIVERSITY OF EDINBURGH, KATARIINA VUORINEN (UNIVERSITY OF TURKU, STUART SULLIVAN (UNIVERSITY OF GLASGOW, UNITED KINGDOM) [email protected] FINLAND), KIRK OVERMYER (UNIVERSITY UNITED KINGDOM), JOHN M CHRISTIE OF HELSINKI, FINLAND), BARBARA MOFFATT (UNIVERSITY OF GLASGOW, UNITED KINGDOM) [email protected] Nitrogen is an essential plant nutrient taken up by the roots in the form of nitrates from the soil. Nitrate and (UNIVERSITY OF WATERLOO, CANADA), STÉPHANE Pathogen recognition by plants leads to accumulation RAVANEL (UNIVERSITÉ GRENOBLE, FRANCE), drought stress are intrinsically linked. When a plant [email protected] of the immune hormone salicylic acid (SA), ERICH GLAWISCHNIG (UNIVERSITÄT MÜNCHEN, is under drought stress, nitrate uptake through the which causes dramatic reprogramming of the GERMANY), SAIJALIISA KANGASJÄRVI Phototropism is the re-orientation of plant growth roots drops due to lack of water. An important enzyme transcriptome to prioritise immune responses. (UNIVERSITY OF TURKU, FINLAND) towards directional light and is important to promote in the process of nitrogen assimilation is nitrate These large-scale changes in gene expression are light capture and early seedling growth. Traditionally, reductase. Nitrate reductase reduces nitrate into dependent on the SA-responsive transcription [email protected] dark-grown (etiolated) seedlings are used to study nitrite and is involved in the reduction of nitrite to the coactivator, NPR1. The coactivator activity of phototropism, although light-grown (de-etiolated) signalling molecule of nitric oxide (NO). Nitric Oxide In a constantly changing environment plants need NPR1 has previously been shown to be regulated by seedlings retain phototropic responsiveness. Phototropin (NO) is implicated through oxidation of substrates to have a rapid and adjustable system for sensing ubiquitination and proteasomal degradation. Our 1 (phot1) is a blue light-activated serine/threonine for ubiquitination through the N-end rule pathway. and responding to the external cues. Stress-induced recent data suggests that ubiquitination of NPR1 is kinase acting as the main photoreceptor mediating This has been shown to be involved in multi-stress reprogramming of primary metabolism and production a multi-step process in which initial ubiquitination hypocotyl phototropism in Arabidopsis. It is generally tolerance, in particular stomatal closure, through of secondary metabolites are essential defence activates NPR1, while processive ubiquitin chain accepted that phototropic curvature ultimately arises stress related transcription factors. Nitrate reductase mechanisms that prevent pathogens and pests from extension mediated by the E4 ligase, UBE4, leads from the establishment of a lateral auxin gradient across is encoded for by two genes; NIA1 and NIA2. In order to colonizing host plant tissues. Defence response in to its deactivation. Importantly, this establishes a the hypocotyl. However, how phot1 coordinates this understand the implications of variable nitrate supply plants is under the control of the cytoplasmic regulatory window of opportunity for NPR1 to activate target auxin redistribution is still unknown. Mutants lacking on stomatal aperture, understanding which gene (NIA1 network and tightly connected with biosynthesis and genes and establish disease resistance. We have the phot1-signalling component Non-Phototropic or NIA2) is involved under differing stress responses recirculation of amino acids, which provide precursors now discovered that in addition to the extension of Hypocotyl 3 (NPH3) are aphototropic and fail to show is critical. There is conflicting information on the role for a variety of secondary compounds. In cruciferous ubiquitin chains, their trimming by deubiquitinases lateral auxin accumulation in response to phototropic of the enzyme nitrate reductase in stomatal closure. I Brassicaceae family plants like Arabidopsis thaliana, (DUBs) is also critical for NPR1 coactivator activity. stimulation. Thus, elucidating the function of NPH3 is have identified single mutants to isolate and examine methionine metabolism is tightly linked with the Accordingly, pharmacological inhibition and genetic key to understanding how phototropism is established. using genetic resources including fluorescent tagging biosynthesis of aliphatic methionine-derived and mutation of the proteasome-associated DUBs, We and others have found that NPH3 is rapidly de- to see where and when the gene is being expressed. indole tryptophan-derived glucosinolates (GSL), major UBP6 and UBP7, led to loss of both NPR1-mediated phosphorylated in response to phot1 activation, which There is also the indication of control of stabilisation secondary compounds that confer resistance against gene expression and immunity in Arabidopsis. Our in turn, induces its re-localisation from the plasma by sumoylation. Individual roles and characteristics insect herbivores and microbial pathogens. In response data suggest that opposing activities of UBE4 and membrane. Here we show that the localisation of NPH3 of NIA1 and NIA2 need to be identified and how they to biotic stress, indole GSL undergo hydroxylation and UBP6/7 ensure that the transcriptional window of correlates with its phosphorylation status. We show that change in response to stress, in particular stomatal transmethylation reactions, and the resulting modified opportunity for NPR1 coactivator remains flexible, a gradient of NPH3 re-localisation is detectable across aperture responses. glucosinolates display diverse biological functions. We allowing adjustment according to immune demand. the upper hypocotyl following phototropic stimulation. have shown that regulatory B’γ of protein phosphatase Compared to etiolated seedlings, de-etiolated seedlings 2A (PP2A-B’γ) physically interacts with INDOLE show enhanced kinetics of phototropic curvature. This GLUCOSINOLATE METHYLTRANSFERASEs (IGMTs) enhancement correlates with reduced levels of NPH3 and specifically controls the methylation of indole de-phosphorylation and re-localisation. Phosphorylation glucosinolates and formation of 4-methoxy-indol-3-yl- is therefore important for regulating NPH3 function. methyl glucosinolate (4MO-I3M) in Arabidopsis leaves. Identification of the in vivo phosphorylation sites of Proteomic and metabolomics approaches revealed NPH3 is now required to assess how dynamic changes that PP2A-B’γ is required to control the abundance in its phosphorylation modulates plant growth responses of oligomeric protein complexes functionally linked to light. with activated methyl cycle and the transmethylation CELL SECTION SYMPOSIUM POSTER ABSTRACTS 38 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 39

C S 17.4 9 WHAT ‘R’ YOU DOING C S 17.5 0 FUNCTIONAL ANALYSIS C S 17.5 1 THE ROLE OF C S 17.5 2 CHARACTERISING THE ROLE HERE? INVESTIGATING THE ROLE OF CYP707A70 GENE (ABA O-GLYCOSYLATION IN PLANT OF ELONGATION FACTOR TU RECEPTOR OF S-ACYLATION IN PLANT DISEASE 8’-HYDROXYLASES) FROM HOT PEPPER DEVELOPMENTAL TRANSITIONS (EFR) PROTEIN KINASE ACTIVITY RESISTANCE PROTEINS (CAPSICUM ANNUUM) IN TRANSGENIC AND PHOSPHORYLATION IN PATTERN- TOBACCO AND TOMATO MONDAY 11 DECEMBER 2017 TRIGGERED IMMUNITY MONDAY 11 DECEMBER 2017 DORIS LUCYSHYN (UNIVERSITY OF NATURAL MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 DIONNE TURNBULL (UNIVERSITY OF DUNDEE, RESOURCES AND LIFE SCIENCES VIENNA, UNITED KINGDOM), PAUL R J BIRCH (UNIVERSITY AUSTRIA), KRISHNA V MUTANWAD (UNIVERSITY YOUNG HEE JOUNG (CHONNAM NATIONAL KYLE W BENDER (THE SAINSBURY LABORATORY, OF DUNDEE, UNITED KINGDOM), PIERS A HEMSLEY OF NATURAL RESOURCES AND LIFE SCIENCES UNIVERSITY, KOREA (SOUTH)), HYUN MIN UNITED KINGDOM), DANIEL COUTO (THE (UNIVERSITY OF DUNDEE, UNITED KINGDOM) VIENNA, AUSTRIA), CLAUDIA MAYRHOFER KIM (CHONNAM NATIONAL UNIVERSITY, KOREA SAINSBURY LABORATORY, UNITED KINGDOM), (UNIVERSITY OF NATURAL RESOURCES AND LIFE (SOUTH)), AH YOUNG KIM (CHONNAM NATIONAL LENA STRANSFELD (THE SAINSBURY LABORATORY, SCIENCES VIENNA, AUSTRIA), ISABELLA ZANGL [email protected] UNIVERSITY, KOREA (SOUTH)), SE HEE PARK UNITED KINGDOM), CYRIL ZIPFEL (THE SAINSBURY (UNIVERSITY OF NATURAL RESOURCES AND LIFE (CHONNAM NATIONAL UNIVERSITY, KOREA LABORATORY, UNITED KINGDOM) Plants are constantly surrounded by potential pests SCIENCES VIENNA, AUSTRIA) (SOUTH)), SANG HOON MA (CHONNAM NATIONAL and pathogens, threatening the health of the plant UNIVERSITY, KOREA (SOUTH)), SEO YOUNG [email protected] and the security of our food production. Unable [email protected] PARK (CHONNAM NATIONAL UNIVERSITY, KOREA to move to escape challenge, plants must defend Detection of pathogenic microbes by plants is (SOUTH)), MI JIN JEON (CHONNAM NATIONAL Plants undergo several developmental transitions themselves in situ, and possess a complex, multi- mediated through perception of pathogen-associated UNIVERSITY, KOREA (SOUTH)), MAI THANH DAT in the course of their life cycle, marked by specific layered innate immune system. A crucial aspect molecular patterns (PAMPs) by plasma membrane (CHONNAM NATIONAL UNIVERSITY, VIETNAM), morphological changes such as altered leaf morphology, of the plants immune response is the recognition (PM)-localised pattern recognition receptors (PRRs). CHUL-HO YUN (CHONNAM NATIONAL UNIVERSITY, the formation of trichomes and the onset of flowering. of specific pest and pathogen ‘effector proteins’ - PAMP perception elicits a battery of downstream KOREA (SOUTH)) The timing of transition from juvenile to adult secreted molecules that manipulate plant processes responses, including reactive oxygen production, phase is regulated by the amount of available sugar to promote the pest or pathogens lifestyle, increasing calcium influxes and MAPK activation, collectively [email protected] accumulating during plant growth. This process is disease potential. Effector recognition is facilitated known as pattern-triggered immunity (PTI). One of mediated by balancing the ratio between miRNA156 by plant resistance (R) proteins, largely belonging to Cytochrome P450 (P450 or CYP) monooxygenases the most well characterised PRRs in Arabidopsis is and miRNA172, thus regulating the downstream the nucleotide-binding leucine-rich repeat (NB-LRR) in plants have important roles in the biosynthesis of the leucine-rich repeat receptor kinase (LRR-RKs) miRNA156 target genes, a family of SPL (SQUAMOSA family, analogous to immune receptors found in animal plant hormones, defence related chemicals, and diverse EFR (ELONGATION FACTOR TU RECEPTOR), which PROMOTER BINDING PROTEIN-LIKE) transcription systems. The modular structure, and interaction secondary metabolites. We isolated CYP707A70 gene, functions co-ordinately with the co-receptor BAK1 factors. In Arabidopsis, mutants in the protein between domains, enables effector recognition which were encoded Abscisic acid 8’-hydroxylase (BRI1-ASSOCIATED RECEPTOR-LIKE KINASE 1; also O-fucosyltransferase SPINDLY (SPY) show accelerated and subsequent activation of these R-proteins, but from a cDNA library of hot pepper (Capsicum an LRR-RK) to detect the bacterial PAMP EF-Tu (or its transition from the juvenile to the adult phase, as well the mechanisms of activation and downstream annuum L. cv. Bukang). The abscisic acid (ABA) is derived peptide elf18). Perception of elf18 by EFR leads as early flowering. O-fucosylation is a posttranslational immune signalling remain poorly understood. one of the important phytohormone that regulates to heterodimerization and subsequent activation of modification and closly connected to O-GlcNAcylation. Recent work on a group of R-proteins from potato, many phygioiological processes in plant. The major the BAK1 protein kinase domain by an as yet unknown In this type of O-glycosylation, either a single fucose or required for resistance to the notorious potato late ABA catabolic pathway is oxidative degradation to mechanism, leading to downstream signalling events. N-acetylglucosamine (GlcNAc) is O-linked to side chains blight pathogen Phytophthora infestans, has revealed 8’-hydroxy ABA In order to understand the roles of the EFR is phosphorylated in vivo, presumably by BAK1, of serine- or threonine residues of nuclear and cytosolic that several of these undergo S-acylation - a reversible CYP707A70 gene in hot pepper, the gene expression and is an active protein kinase (PK) itself, but whether proteins. In the current working model O-fucosylation fatty acid based post-translational modification. patterns in various hot pepper tissues were analysed. EFR protein kinase activity is required for immunity is and O-GlcNAcylation compete for the same targets, with S-acylation is particularly known for its role in The CYP707A70 gene was highest expressed in unknown. In order to assess the role of EFR PK activity counteracting functional effects. Given the observed membrane anchoring and localisation but, due to its leaves. The expression level of gene was increased in immunity we have generated a series of kinase early transition phenotypes of spy-mutants, we are reversibility, is also linked to regulating aspects of during the growth phase of the fruit but decreased inactive EFR mutants and are testing their capacity currently investigating the role of O-glycosylation in protein function such as activation, trafficking, and in maturation. In flower, the relative transcript level to activate PTI responses in transgenic Arabidopsis the regulation of miRNA156 and miRNA172, potentially protein-protein interaction. Ongoing investigation of CYP707A70 was mainly expressed in ovary. To thaliana. Preliminary analyses indicate that EFR PK in response to the accumulation of sugar in growing has shown that S-acylation occurs at multiple sites, demonstrate the function of the CYP707A70 genes in activity is dispensable for at least some branches tissues. Preliminary data suggest that spy-mutants in multiple domains, within R proteins, suggesting plant, this gene was cloned into plant expression vector of PTI. Additionally, our studies aim to identify the indeed show altered levels of these miRNAs. Moreover, a complex role for this dynamic post-translational and transformed into tobacco (Nicotiana tabacum sites of EFR phosphorylation, the PKs that catalyse we are testing if O-glycosylation also affects the modification in plant R-protein function. Our latest cv. Xanthi NC) and tomato (Solanum lycopersicum these events, and the functional importance of EFR function of SPLs. These experiments will contribute data on the functional consequences of R-protein cv. Micro-Tom). The CYP707A70 over-expression phosphorylation for PTI. Collectively, these studies to our understanding of the molecular mechanisms of S-acylation during plant defence responses will transgenic tobacco plants showed the wilting will provide insight into the molecular details of how O-glycosylation in the regulation of plant development. be presented. phenotype. Furthermore, transgenic tobacco plants immune receptor activation controls the downstream Supported by the Austrian Academy of showed that down regulated seed formation and pollen processes responsible for disease resistance. Sciences ÖAW and the Austrian Science Fund FWF. viability compare to non-transgenic tobacco.

CELL SECTION SYMPOSIUM POSTER ABSTRACTS 40 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 41

C S 17.5 3 THE ROLE OF THE PEPTIDASE such as maize and Canola. Molecularly, BB activates halleri plants,which have the ability to tolerate and C S 17.5 6 A DOWNY MILDEW EFFECTOR DA1 AND THE E3-LIGASE BIG BROTHER the latent peptidase DA1 by ubiquitination in a novel hyper-accumulate cadmium. First, we analysed the IMPOSES HOST SUSCEPTIBILITY IN REGULATING CELL PROLIFERATION activation-repression mechanism. Subsequently, patterns of lysine methylation using a combination BY MODULATING THE ACTIVITY OF AND SENESCENCE IN PLANTS the activated DA1 destabilises positive regulators of of western blot and mass spectrometry analyses. We growth, such as UBP15 and the transcription factors showed that some methylproteins are differentially A HOST RING E3 LIGASE REQUIRED TCP14 and TCP15. In addition, DA1 cleaves BB in a methylated in response to cadmium stress. Then, we FOR IMMUNITY MONDAY 11 DECEMBER 2017 negative feedback loop. The C-terminal fragment of analysed the expression of genes coding protein lysine HANNES VANHAEREN (VIB CENTER FOR PLANT BB is recognized and ubiquitinated by the N-end rule methyltransferases and demethylases in different MONDAY 11 DECEMBER 2017 E3 Ubiquitin ligase PROTROLYSIS1 and marked for transcriptomic datasets related to cadmium stress. SYSTEMS BIOLOGY, BELGIUM), HUI DONG DAE SUNG KIM (THE SAINSBURY LABORATORY, proteasomal degradation. These events result in a We showed that transcriptional regulation of these (JOHN INNES CENTRE, UNITED KINGDOM), UNITED KINGDOM), SHUTA ASAI (CENTER FOR unidirectional transition from cell proliferation to cell genes had little impact during response and adaptation JACK DUMENIL (JOHN INNES CENTRE, UNITED SUSTAINABLE RESOURCE SCIENCE RIKEN, JAPAN), expansion. Recently, we have found that two additional to a stress induced by cadmium. Last, we developed KINGDOM), FU-HAO LU (JOHN INNES CENTRE, GIULIA FURLAN (LEIBNIZ INSTITUTE OF PLANT UNITED KINGDOM), LI NA (STATE KEY ubiquitin-specific proteases, UBP12 and UBP13, a screening procedure to analyse the cadmium BIOCHEMISTRY, GERMANY), MARCO TRUJILLO LABORATORY OF PLANT CELL AND CHROMOSOME interact with DA1 in vivo. These de-ubiquitinating tolerance of A. thaliana mutants for genes coding (LEIBNIZ INSTITUTE OF PLANT BIOCHEMISTRY, ENGINEERING CAS, CHINA), CHRISTIN NAUMANN enzymes might play an important role in plant growth methyltransferases. We identified and characterised GERMANY), PASCAL FALTER-BRAUN (INSTITUTE OF (LEIBNIZ INSTITUTE OF PLANT BIOCHEMISTRY and development by de-activating DA1 and thus two mutants that are either more tolerant or more NETWORK BIOLOGY HELMHOLTZ ZENTRUM MÜNCHEN, (IPB), GERMANY), MARIA KLECKER (LEIBNIZ promoting cell division. sensitive to cadmium than wild-type plants. Together, GERMANY), JONATHAN D G JONES (THE SAINSBURY INSTITUTE OF PLANT BIOCHEMISTRY (IPB), our results show that the fine-tuning regulation of non- LABORATORY, UNITED KINGDOM) GERMANY), LIESBETH DE MILDE (VIB CENTER FOR histone proteins by lysine methylation has a role in PLANT SYSTEMS BIOLOGY, BELGIUM), RACHEL the response of Arabidopsis plants to cadmium stress. [email protected] PRIOR (JOHN INNES CENTRE, UNITED KINGDOM), C S 17.5 4 LYSINE METHYLATION CAROLINE SMITH (JOHN INNES CENTRE, UNITED OF NON-HISTONE PROTEINS IS Pathogen effectors subvert host immunity by KINGDOM), NEIL MCKENZIE (JOHN INNES INVOLVED IN THE RESPONSE OF manipulating host physiology for the benefit of the CENTRE, UNITED KINGDOM), GERHARD SAALBACH ARABIDOPSIS PLANTS TO A C S 17.5 5 DYNAMIC S-ACYLATION pathogen. Hyaloperonospora arabidopsidis contains (JOHN INNES CENTRE, UNITED KINGDOM), STRESS INDUCED BY CADMIUM LIANGLIANG CHEN (STATE KEY LABORATORY OF IN PLANTS ~140 effector candidates carrying a signal peptide and PLANT CELL AND CHROMOSOME ENGINEERING an RxLR motif. HaRxL62 promotes plant susceptibility CAS, CHINA), TIAN XIA (STATE KEY LABORATORY MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 and is highly expressed during infection. Using IP-mass OF PLANT CELL AND CHROMOSOME ENGINEERING spec, we identified RING type E3 ligase (RING62) as CAS, CHINA), MATHILDE SEGUELA (JOHN NELSON BCB SERRE (UNIVERSITY GRENOBLE UPENDO LUPANGA (UNIVERSITY OF DUNDEE, an HaRxL62 interactor. RING62 is single copy in INNES CENTRE, UNITED KINGDOM), YING CHEN ALPES, FRANCE), OCÉANE GIGAREL (UNIVERSITY UNITED KINGDOM) Arabidopsis, but well conserved in dicots as well as (VIB CENTER FOR PLANT SYSTEMS BIOLOGY, GRENOBLE ALPES, FRANCE), JUSTINE CHOULET monocots. From previous studies, RING62 interacts (UNIVERSITY GRENOBLE ALPES, FRANCE), BELGIUM), VERONIQUE STORME (VIB CENTER FOR [email protected] in yeast two hybrid with RCD1, TCP14, TCP21, SYLVIE FIGUET (UNIVERSITY GRENOBLE PLANT SYSTEMS BIOLOGY, BELGIUM), NATHALIE SAG102 and JAZ3. RING62 shows in vivo and in vitro ALPES, FRANCE), MASSIMILIANO CORSO (FREE With the discovery that a large proportion of the plant GONZALEZ (VIB CENTER FOR PLANT SYSTEMS auto-ubiquitination activity in an ATP-dependent UNIVERSITY OF BRUSSELS, BELGIUM), CLAUDE proteome is S-acylated, it has become apparent that this BIOLOGY, BELGIUM), NICO DISSMEYER (LEIBNIZ manner. To reveal the effect of HaRxL62 on E3 ligase ALBAN (UNIVERSITY GRENOBLE ALPES, FRANCE), form of lipid modification on cysteines is an important INSTITUTE OF PLANT BIOCHEMISTRY (IPB), activity of RING62, we monitored E3 ligase activity NATHALIE VERBRUGGEN (FREE UNIVERSITY OF post-translational modification that may have a vital GERMANY), YUNHAI LI (STATE KEY LABORATORY after adding HaRxL62 in vitro as well as in vivo. E3 ligase BRUSSELS, BELGIUM), JACQUES BOURGUIGNON role in plant growth and development. S-acylation was OF PLANT CELL AND CHROMOSOME ENGINEERING activity seemed to increase in the presence of HaRxL62. CAS, CHINA), MICHAEL W BEVAN (JOHN INNES (UNIVERSITY GRENOBLE ALPES, FRANCE), initially thought to act as a membrane anchor for soluble However, RING62 self-association was not affected CENTRE, UNITED KINGDOM), DIRK INZÉ (VIB STÉPHANE RAVANEL (UNIVERSITY GRENOBLE proteins but the fact that S-acylation is reversible and in the presence of HaRxL62. ring62 mutants show CENTER FOR PLANT SYSTEMS BIOLOGY, BELGIUM) ALPES, FRANCE) also occurs on integral membrane proteins, suggests compromised resistance against Hpa and Pst DC3000. that it is not just a means of anchoring proteins to To reveal the regulatory network between HaRxL62 [email protected] [email protected] membranes but may have a role in regulating important and RING62, we conducted yeast two hybrid screening aspects of a protein such as function, localisation, How plants grow from a small seed to their final Protein methylation on lysine residues is emerging using HaRxL62 or RING62 as a bait, respectively. activity and stability. With the aid of stable isotope stature appeals to the imagination of many people. as an important and widespread post-translational TCP 3, 7, 9 and 15 interact with both HaRxL62 and labelling with amino acids in cell culture (SILAC) and Uncovering the molecular mechanisms that determine modification affecting many cellular processes in RING62, whereas additional TCPs such as TCP 10, 13 CLICK chemistry with alkyne fatty acids, we aim plant organ growth and size is therefore a challenging eukaryotes. However, methylation of non-histone and 23 were detected only in RING62 screening. Our to identify proteins that undergo dynamic changes and fascinating research topic. The E3-ligase BIG proteins is still a poorly known process in plants. goal is to elucidate how HaRxL62 elevates virulence in S-acylation as part of their regular cell function. BROTHER (BB) and the peptidase DA1 work in To improve our knowledge about this modification, by rendering RING62 hyperactive, so that HaRxL62 concert to restrict cell proliferation and leaf longevity we analysed the dynamics of lysine methylation on perturbs the balance of turnover and accumulation of in Arabidopsis. Mutants of these genes produce larger non-histone proteins in plants exposed to the toxic its targets to suppress plant immune responses. organs that contain more cells whereas overexpression metal cadmium. We conducted our study using reduces growth. Recent findings have demonstrated Arabidopsis thaliana and Arabidopsis lyrata plants, the importance of this pathway for yield in crop plants, which are sensitive to cadmium, and with Arabidopsis CELL SECTION SYMPOSIUM POSTER ABSTRACTS 42 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 43

C S 17.5 7 UNDERSTANDING THE ROLE OF C S 17.5 8 CONTROL OF GROWTH CS17.59 UNDERSTANDING THE ROLE OF C S 17.6 0 THE ARABIDOPSIS THALIANA SUMOYLATION IN REGULATING LIGHT BY PHOSPHORYLATION AND SUMOYLATION IN REGULATING LIGHT RHIZOBIALE-LIKE PHOSPHATASE SIGNALLING COMPONENTS IN PLANTS UBIQUITYLATION OF DA1 PEPTIDASE SIGNALLING COMPONENTS IN PLANTS 2 IS A NOVEL D-GROUP MITOGEN ACTIVATED PROTEIN KINASE (MAPK) MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 TYROSINE-SPECIFIC PPP-FAMILY PROTEIN PHOSPHATASE EIRINI KAISERLI (UNIVERSITY OF GLASGOW, HUI DONG (JOHN INNES CENTRE, UNITED GIORGIO PERRELLA (UNIVERSITY OF GLASGOW, UNITED KINGDOM), MHAIRI L H DAVIDSON KINGDOM), CAROLINE SMITH (JOHN INNES UNITED KINGDOM), MHAIRI L H DAVIDSON MONDAY 11 DECEMBER 2017 (UNIVERSITY OF GLASGOW, UNITED KINGDOM), CENTRE, UNITED KINGDOM), MICHAEL BEVAN (UNIVERSITY OF GLASGOW, UNITED KINGDOM), JONNA AITTA (UNIVERSITY OF GLASGOW, UNITED (JOHN INNES CENTRE, UNITED KINGDOM) JONNA AITTA (UNIVERSITY OF GLASGOW, ANNE MARIE LABANDERA (UNIVERSITY OF KINGDOM), GIORGIO PERRELLA (UNIVERSITY OF UNITED KINGDOM), ARI SADANANDOM (DURHAM CALGARY, CANADA), R GLEN UHRIG (UNIVERSITY UNIVERSITY, UNITED KINGDOM), EIRINI GLASGOW, UNITED KINGDOM), ARI SADANANDOM [email protected] OF ALBERTA, CANADA), RYAN TOTH (UNIVERSITY (DURHAM UNIVERSITY, UNITED KINGDOM) KAISERLI (UNIVERSITY OF GLASGOW, OF CALGARY, CANADA), KEATON COLVILLE The characteristic sizes and shapes of plant organs are UNITED KINGDOM) (UNIVERSITY OF CALGARY, CANADA), KENNETH K S [email protected] established by the interplay of cell proliferation and NG (UNIVERSITY OF CALGARY, CANADA), GREG G B cell growth. These peptidases, DA1 and DAR1, cleave [email protected] MOORHEAD (UNIVERSITY OF CALGARY, CANADA) Light is an essential informational signal that promotes proteins that promote growth, such as members of plant growth and development. Photoreceptors, light Light is an essential informational signal that promotes the TCP family and UBP15, which de-ubiquitylates [email protected] signalling components and transcriptional regulators plant growth and development. Photoreceptors, light histones. A key question is how the activities of DA1 have been observed to translocate into the nucleus signalling components and transcriptional regulators and DAR1 are regulated during organ growth. We The study of tyrosine phosphorylation in plants and form highly dynamic subnuclear structures have been observed to translocate into the nucleus and have shown that receptor-like kinases (RLK) called has been largely neglected due to the lack of classic known as photobodies. The composition, mode of form highly dynamic subnuclear structures known TMK1 and TMK4, together with the co-receptor tyrosine kinases and underrepresentation of tyrosine formation and molecular function of photobodies as photobodies. The composition, mode of formation BAK1, phosphorylate DA1in vitro, and that DA1 is phosphatases compared to humans. However, advanced remain elusive. Posttranslational modification of and molecular function of photobodies remain elusive. phosphorylated in vivo. Genetic analyses of quadruple phosphoproteomics studies have revealed that the proteins represents a regulatory mechanism that Posttranslational modification of proteins represents a tmk1 tmk4 da1 dar1loss-of-function mutants show abundance of phospho-tyrosine residues in plants underpins several cellular processes. The reversible regulatory mechanism that underpins several cellular that the strongly reduced growth of double tmk1 parallels humans. This strongly suggests that in plants attachment to nuclear proteins of the ∼100-amino- processes. The reversible attachment to nuclear tmk4 mutants can be recovered to almost wild- tyrosine phosphorylation is as important as in humans, yet acid protein small ubiquitin-like modifier (SUMO) proteins of the ∼100-amino-acid protein small ubiquitin- type growth by loss of DA1and DAR1function. This we have limited knowledge about the players responsible controls a broad spectrum of cellular activities like modifier (SUMO) controls a broad spectrum of suggested that lowered TMK1 and TMK4 activity of these events. The Arabidopsis thaliana Rhizobiale-like such as gene expression, chromatin remodelling, cellular activities such as gene expression, chromatin reduces growth through DA1 and DAR1 activity. We phosphatase 2 (AtRLPH2) is a novel protein phosphatase signal transmission, nuclear trafficking and protein remodelling, signal transmission, nuclear trafficking identified two clusters of phosphorylated amino acids not found in mammals which, according to bioinformatics stabilisation. TANDEM ZINC-FINGER-PLUS3 and protein stabilisation. TANDEM ZINC-FINGER- in functionally conserved regions of DA1 using LC-MS/ analysis, clusters with the serine/threonine specific (TZP) is a light signalling component that promotes PLUS3 (TZP) is a light signalling component that MS. Phosphomimetic substitutions of phosphoserine phospho-protein phosphatase (PPP) group. Here, we hypocotyl elongation and flowering in plants. TZP promotes hypocotyl elongation and flowering in plants. and phosphothreonine decreased DA1 peptidase demonstrate that AtRLPH2 surprisingly behaves like interacts with the red-light receptor phytochrome TZP interacts with the red-light receptor phytochrome activity. This provides a plausible mechanism for TMK1 a tyrosine phosphatase. AtRLPH2 is inhibited by the B (phyB) in small, distinct, transcriptionally active B (phyB) in small, distinct, transcriptionally active and TMK4 promoting growth by reducing DA1 activity. specific tyrosine phosphatase inhibitor, orthovanadate nuclear bodies. Recently, TZP was identified as a SUMO nuclear bodies. Recently, TZP was identified as a SUMO Thus, a dynamic balance of phosphorylation and and dephosphorylates phospho-tyrosine substrates conjugate in proteomic analysis for proteins bound conjugate in proteomic analysis for proteins bound ubiquitylation of DA1 may contribute to establishing presenting essentially no activity towards phospho- to a SUMO1 variant. Furthermore, light-reversible to a SUMO1 variant. Furthermore, light-reversible final organ sizes.TMK4/BARK1mutants have reduced serine/threonine residues. This shows for the first time sumoylation was recently shown to negative regulate sumoylation was recently shown to negative regulate sensitivity to auxin, and it interacts with BAK1, a co- that a member of the plant PPP-family of phosphatases the signalling state of phyB. To understand the role the signalling state of phyB. To understand the role receptor of the brassinosteroid (BR) receptor BR1. This has the capability to dedicate its activity solely toward of TZP sumoylation sites we employed a site directed of TZP sumoylation sites we employed a site directed provides an opportunity to understand how growth phospho-tyrosine. Additionally, we elucidated AtRLPH2 mutagenesis approach and mutated the different mutagenesis approach and mutated the different regulators such as auxin and BR might control DA1 and crystal structure in presence and absence of tungstate lysines. Two site prediction algorithms were used to lysines. Two site prediction algorithms were used to influence organ size. (as phospho-mimic) at 1.8 and 2.0 Å, respectively. This identify these sumoylation sites and SUMO interacting identify these sumoylation sites and SUMO interacting provided detailed mechanistic insight into its mode of motifs (SIM) in TZP protein sequence. Preliminary motifs (SIM) in TZP protein sequence. Preliminary action. AtRLPH2’s structure along with biochemical data show that sumoylation sites are important for data show that sumoylation sites are important for validation, revealed the necessary conditions its localisation and affect the size of TZP photobodies: localisation and affect the size of TZP photobodies: as the substrates need to possess making Mitogen Activated as the number of sumoylation sites disrupted increases, number of sumoylation sites disrupted increases, there Protein Kinases (MAPKs) perfect candidates. Last, there are fewer and larger photobodies. Overall, are fewer and larger photobodies. Overall, these findings to identify AtRLPH2 endogenous substrates, a these findings support the role of sumoylation in support the role of sumoylation in light signalling. phosphoproteomics study was performed by comparing light signalling. phospho-tyrosine peptides from wild type and two atrlph2 knockout plant lines. AtRLPH2 was found and validated to be a D-group specific MAPK tyrosine phosphatase. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 44 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 45

C S 17.6 1 GENOMIC AND PHENOMIC C S 17.6 2 UNDERSTANDING THE ROLE OF C S 17.6 3 ROLE OF POST- C S 17.6 4 RPT2 AND NCH1 ARE SCREENS FOR FLOWER RELATED RING SUMOYLATION IN REGULATING LIGHT TRANSLATIONAL MODIFICATIONS KEY FACTORS FOR THE BLUE- TYPE UBIQUITIN E3 LIGASES IN SIGNALLING COMPONENTS IN PLANTS THAT REGULATES SIGNALLING FROM LIGHT RECEPTOR PHOTOTOROPIN- ARABIDOPSIS G-PROTEINS IN CAPSICUM ANNUUM SIGNALLING PATHWAY IN LAND PLANTS MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MHAIRI L H DAVIDSON (IMCSB UNIVERSITY OF MIRKO PAVICIC (UNIVERSITY OF HELSINKI, GLASGOW, UNITED KINGDOM), JONNA AITTA LUIS A LIGHTBOURN (LIGHTBOURN RESEARCH NORIYUKI SUETSUGU (THE UNIVERSITY OF FINLAND), KATRIINA MOUHU (UNIVERSITY OF (IMCSB UNIVERSITY OF GLASGOW, UNITED INSTITUTE, MEXICO), LUIS A AMARILLAS GLASGOW, UNITED KINGDOM), STUART SULLIVAN HELSINKI, FINLAND), FENG WANG (UNIVERSITY KINGDOM), GIORGIO PERRELLA (IMCSB (LIGHTBOURN RESEARCH INSTITUTE, MEXICO) (UNIVERSITY OF GLASGOW, UNITED KINGDOM), OF HELSINKI, FINLAND), MARCELINA BILICKA UNIVERSITY OF GLASGOW, UNITED KINGDOM), TAKAYUKI KOHCHI (KYOTO UNIVERSITY, JAPAN), (UNIVERSITY OF HELSINKI, FINLAND), ERIK ARI SADANANDOM (UNIVERSITY OF DURHAM, [email protected] JOHN M CHRISTIE (UNIVERSITY OF GLASGOW, CHOVANČEK (UNIVERSITY OF HELSINKI, UNITED KINGDOM), EIRINI KAISERLI (IMCSB UNITED KINGDOM) FINLAND), KRISTIINA HIMANEN (UNIVERSITY OF UNIVERSITY OF GLASGOW, UNITED KINGDOM) The multiple roles played by G proteins demonstrate HELSINKI, FINLAND) the importance of the study and characterisation of [email protected] [email protected] these proteins in plants with agricultural and food [email protected] Plant photoreceptor kinases known as the importance, such as Capsicum annuum. A better Light is an essential informational signal that promotes phototropins (phots) mediate various blue light Flower development and flowering time control understanding of the regulation of signal transduction plant growth and development. Photoreceptors, light responses including phototropism, chloroplast integrate endogenous and environmental signals to mediated by G-proteins will require the identification signalling components and transcriptional regulators movement, stomatal opening, and leaf flattening and promote vegetative to reproductive growth transition. of post-translational modifications of these proteins. have been observed to translocate into the nucleus thus facilitate the light capture for photosynthesis. In The molecular networks involved are complex and Given the discussion above, the objectives of this and form highly dynamic subnuclear structures Arabidopsis thaliana, two phot-interacting proteins incorporate different pathways and modes of signal research project were to conduct the characterisation known as photobodies. The composition, mode of NONPHOTOTROPIC HYPOCOTYL3 (NPH3) and transduction. In plants, ubiquitin mediated protein of the G protein alpha subunit (Gα) from Cucumis formation and molecular function of photobodies ROOT PHOTOTROPISM2 (RPT2), that belong to degradation pathway has been proposed to be an sativus. The numerous biological functions of Gα are remain elusive. Posttranslational modification of NPH3/RPT2-like (NRL) BTB/POZ domain protein important mode of signalling in flowering control. highly dependent upon specific post-translational proteins represents a regulatory mechanism that family, mediate phototropism and leaf flattening. To thoroughly study the role of ubiquitin pathway modifications that guide their subcellular localisation underpins several cellular processes. The reversible Recently, we found that RPT2 and another NRL protein in the molecular regulation of flowering we took a and interaction with regulators and effectors. Several attachment to nuclear proteins of the ∼100-amino- NRL PROTEIN FOR CHLOROPLAST MOVEMENT1 reverse genetic approach to identify flower related important functional sites, such as receptor-binding acid protein small ubiquitin-like modifier (SUMO) (NCH1) are essential for the chloroplast accumulation Ubiquitin Proteasome System components. The sites, effector binding sites, GTP-binding sites, important controls a broad spectrum of cellular activities response. The RPT2/NCH1 ortholog from the liverwort RING type ubiquitin E3 ligase family was chosen as sites for maintaining the structural stability of the such as gene expression, chromatin remodelling, Marchantia polymorpha, MpNCH1, is also essential targets of the genomic screen, because of its large examined protein and post-translational modified sites signal transmission, nuclear trafficking and protein for chloroplast accumulation in this organism, member number and versatile roles. To this aim, the were identified. Modifications of their carboxyl termini stabilisation. TANDEM ZINC-FINGER-PLUS3 (TZP) is indicating that the RPT2/NCH1 subfamily is an whole list of Arabidopsis RING E3 ligases was retrieved include the addition of palmitate to cysteine residues; a light signalling component that promotes hypocotyl essential signalling factor for this response in land and curated from the Arabidopsis genome v11. Using the incorporation of this lipid favours the interaction of elongation and flowering in plants. TZP interacts with plants. However, NCH1 and RPT2 do exhibit different Genevestigator data sets, RING genes were grouped Gα with its membrane. Secondly, the amino-terminal the red-light receptor phytochrome B (phyB) in small, functions in that NCH1 is specific to chloroplast in different flower organs and over developmental region of Gα is susceptible to the addition of myristic distinct, transcriptionally active nuclear bodies. movement, whereas RPT2 additionally regulates stages categories from bolting to mature siliques, acid, this modification contributes to the interaction Recently, TZP was identified as a SUMO conjugate phototropism and leaf flattening in Arabidopsis. To according to their relative differential expression. between Gα molecules and cell membrane. To the best of in proteomic analysis for proteins bound to a SUMO1 investigate the functional differences between RPT2 Known flowering regulators were identified in these our knowledge, this study is of the first investigations in variant. Furthermore, light-reversible sumoylation and NCH1, we have performed promoter swapping categories through literature search and representative which the Gα from Cucumis sativus has been analysed; was recently shown to negatively regulate the analysis between Arabidopsis RPT2 and NCH1 and also mutants were purchased for functional analysis by thus, the findings of this study are highly significant. signalling state of phyB. To understand the role of expressed MpNCH1 in the rpt2nch1 double mutant of growth and morphological phenotyping. To this end, TZP sumoylation sites we employed a site directed Arabidopsis. Irrespective of which promoter was used, a workflow was established for high throughput mutagenesis approach and mutated the different RPT2, but not NCH1, could mediate phototropism, phenotypic screening of growth, morphology, and lysines. Two site prediction algorithms were used to indicating that RPT2 and NCH1 are not functionally flowering of nearly a thousand Arabidopsis plants in identify these sumoylation sites and SUMO interacting equivalent in the regulation of phototropism. one experimental round. motifs (SIM) in TZP protein sequence. Preliminary Furthermore, MpNCH1 could partially rescue the data show that sumoylation sites are important for phototropic defects of rpt2nch1 seedlings. These localisation and affect the size of TZP photobodies: latter findings suggest that NCH1 has lost the ability as the number of sumoylation sites disrupted increases, to regulate phototropism after the separation of RPT2 there are fewer and larger photobodies. Overall, and NCH1 during seed plant evolution. these findings support the role of sumoylation in light signalling. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 46 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 47

REPRESSION OF ‘LURP’ (EMF2), providing new insight into how proteins can C S 17.6 5 C S 17.6 6 VERNALIZATION2 IS become co-opted to the N-end rule pathway during C S 17.6 8 S-ACYLATION: REGULON BY THE F-BOX PROTEIN AND AN OXYGEN- AND NITRIC OXIDE- evolution to provide new functions. Finally, we have WHAT THE FLS2 IS GOING ON? JA RECEPTOR, COI1 REGULATED SUBSTRATE OF THE N-END found that EMF2c in Barley is also a substrate of the RULE PATHWAY OF PROTEOLYSIS N-end rule pathway and may represent a functional MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 homologue of VRN2. CHARLOTTE H HURST (DUNDEE UNIVERSITY AT THE MONDAY 11 DECEMBER 2017 CLARA WILLIAMS (VIB, BELGIUM), LAURENS JAMES HUTTON INSTITUTE, UNITED KINGDOM), PAUWELS (VIB, BELGIUM), ALAIN GOOSSENS HANNAH M TEDDS (UNIVERSITY OF BIRMINGHAM, PIERS A HEMSLEY (DUNDEE UNIVERSITY AT THE (VIB, BELGIUM) UNITED KINGDOM), MARK BAILEY (UNIVERSITY C S 17.6 7 NUCLEOREDOXIN GUARDS JAMES HUTTON INSTITUTE, UNITED KINGDOM) OF BIRMINGHAM, UNITED KINGDOM), CHARLENE AGAINST OXIDATIVE STRESS BY [email protected] DAMBIRE (UNIVERSITY OF NOTTINGHAM, PROTECTING ANTIOXIDANT ENZYMES [email protected] UNITED KINGDOM), GUILLERMINA M MENDIONDO Plants, as sessile organisms, have evolved to coordinate (UNIVERSITY OF NOTTINGHAM, UNITED Receptor-Like Kinases (RLK) conduct extracellular MONDAY 11 DECEMBER 2017 spatial and temporal signals to allow them to internally KINGDOM), COLLEEN SPRIGG (UNIVERSITY signals across the plasma membrane into anticipate a myriad of stresses. They optimize their cells, allowing cells to respond and adapt to OF BIRMINGHAM, UNITED KINGDOM), SOPHIE RUMANA KEYANI (COMSATS INSTITUTE OF chance of survival through intersecting hormonal MOGG (UNIVERSITY OF BIRMINGHAM, UNITED INFORMATION TECHNOLOGY, ISLAMABAD, environmental changes. FLS2, the most widely- networks that enable them to correctly amplify or KINGDOM), RORY OSBORNE (UNIVERSITY PAKISTAN), SOPHIE KNEESHAW (UNIVERSITY studied plant RLK, is the receptor for the bacterial dampen specific defence responses. For instance, OF BIRMINGHAM, UNITED KINGDOM), OF EDINBURGH, UNITED KINGDOM), VALÉRIE protein flagellin and we have found that FLS2 is upon mechanical wounding the plant responds by MICHAEL J HOLDSWORTH (UNIVERSITY OF DELORME-HINOUX (UNIVERSITÉ PERPIGNAN S-acylated. S-acylation is a reversible and dynamic producing the conserved plant hormone jasmonate NOTTINGHAM, UNITED KINGDOM), DANIEL VIA DOMITIA CNRS LABORATOIRE GÉNOME ET post-translational protein modification whereby (JA). JA acts to coordinate the recruitment of the JAZ J GIBBS (UNIVERSITY OF BIRMINGHAM, DÉVELOPPEMENT DES PLANTES, FRANCE), LISA fatty acids are added to cysteine residues, but repressor proteins by the Skp, Cullin, F-Box complex, UNITED KINGDOM) IMRIE (UNIVERSITY OF EDINBURGH, UNITED the effects of S-acylation on protein function are marking them for ubiquination and subsequent KINGDOM), GARY J LOAKE (UNIVERSITY OF largely unknown. Here, using FLS2 as a model, we degradation by the 26S proteasome system. Much H.TED D S @ H OT M A IL.C O M EDINBURGH, UNITED KINGDOM), THIERRY LE describe the effects of S-acylation on RLK function. remains to be elucidated about how hormones relay BIHAN (UNIVERSITY OF EDINBURGH, UNITED In plants treated with bacterial flagellin levels of these signals to increase plant fitness. Interestingly, The N-end rule pathway of proteolysis targets proteins KINGDOM), JEAN-PHILIPPE REICHHELD S-acylated FLS2 rapidly increase. To identify when we have discovered that COI1 can repress the salicylic for destruction based on the nature of their N-terminus. (UNIVERSITÉ PERPIGNAN VIA DOMITIA CNRS during FLS2 signalling S-acylation is occurring, acid (SA) regulated genes in the ‘LURP regulon’, which We have shown that the N-end rule pathway in LABORATOIRE GÉNOME ET DÉVELOPPEMENT mutants in FLS2 signalling pathway components are required for defence against oomycetes, in a manner Arabidopsis regulates the ‘Methionine-Cysteine (MC)- DES PLANTES, FRANCE), STEVEN H SPOEL were tested for flagellin-mediated increases in FLS2 independent of the JA pathway. Better understanding initiating’ protein -VERNALIZATION2 (VRN2). VRN2 (UNIVERSITY OF EDINBURGH, UNITED KINGDOM) S-acylation. Loss of components required for activation of how COI1 modulates this response, and conversely, functions to coordinate cold-responsive flowering and (co-receptor BAK1) or attenuation (E3 ubiquitin ligases how COI1 itself is modulated (post-translationally), has several other key developmental roles. VRN2 is one [email protected] PUB12/13) prevented the flagellin-mediated increase will uncover novel JA-independent roles of COI1 and of three plant homologues of the Drosophila protein in FLS2 S-acylation. However, mutants in endocytic Cellular accumulation of reactive oxygen species (ROS) help in our molecular understanding of how plants SUPPRESSOR OF ZESTE12 (Su(z)12), which functions processes (DYNAMIN-RELATED PROTEIN 2B) not is associated with a wide range of developmental and coordinate defence against pathogens. as part of the polycomb repressive complex2 (PRC2), only showed a wild-type increase in FLS2 S-acylation stress responses. Although cells have evolved to use a conserved eukaryotic complex that regulates the but accumulated S-acylated FLS2. This suggests that ROS as signalling molecules, their chemically reactive epigenetic silencing of genes through depositing the S-acylation occurs after ubiquitination but before nature also poses a threat. Antioxidant systems are H3K27me3 repressive mark to chromatin. Here we endocytosis of activated FLS2 and we hypothesise required to detoxify ROS and prevent cellular damage, provide in vitro and in vivo evidence that VRN2 is a that S-acylation is required for promoting endocytosis but little is known about how these systems manage physiological substrate of the N-end rule pathway. of activated receptor. Initial characterisation to function in hostile, ROS-rich environments. Here VRN2 is stabilised under hypoxia and NO-limited of FLS2 mutants that cannot undergo flagellin- we show that during oxidative stress in plant cells, the conditions and post-translational accumulation of mediated S-acylation suggest that S-acylation is pathogen-inducible oxidoreductase Nucleoredoxin 1 VRN2 during vernalisation is linked to its regulation required for FLS2 mediated MAPK activation, gene (NRX1) targets enzymes of major hydrogen peroxide by the N-end rule. One hypothesis to explain VRN2 expression and growth inhibition in Arabidopsis. (H2O2)-scavenging pathways, including catalases. stabilisation is that cold-induced VERNALIZATION The site of S-acylation within FLS2 is conserved Mutant nrx1 plants displayed reduced catalase INSENSITIVE3 (VIN3) shields the MC terminus to throughout the RLK superfamily. Based on our data, we activity and were hypersensitive to oxidative stress. prevent it becoming a target for degradation by the propose that S-acylation is an entirely novel regulatory Remarkably, catalase was maintained in a reduced state E3 ligase PROTEOLYSIS6 (PRT6). However, in vitro factor affecting RLK function. by substrate interaction with NRX1, a process necessary and via inducible VIN3 transgenic lines VRN2 is for its H2O2-scavenging activity. These data suggest that still degraded in the presence of VIN3. Additionally, unexpectedly H2O2-scavenging enzymes experience the destabilising N-terminus of VRN2 likely arose oxidative distress in ROS-rich environments and require following gene duplication and N-terminal truncation reductive protection from NRX1 for optimal activity. of an ancient homologue of EMBRYONIC FLOWER2 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 48 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 49

C S 17.6 9 SUMO PROTEASES C S 17.7 0 POST-TRANSLATIONAL C S 17.7 1 TRANSCRIPTIONAL ANALYSIS C S 17.72 EXPRESSION-FUNCTIONAL OTS1 AND 2 CONTROL FILAMENT MODIFICATIONS (PTMS) IN PLANT OF OTS SUMO PROTEASE MUTANTS STUDIES OF PHOSPHOENOLPYRUVATE ELONGATION THROUGH A DELLA- PROTEINS: PHOSPHOENOLPYRUVATE REVEALS NEW SIGNALLING NODES CARBOXYLASE KINASE (PEPCK) DEPENDENT MECHANISM CARBOXYLASE (PEPC) AS A CASE THAT PROMOTE BIOTIC STRESS OF STUDY TOLERANCE IN PLANTS MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 DHIYA D ZAWAWI (UNIVERSITY OF SHEFFIELD, ALBERTO AC CAMPANARO (DURHAM UNIVERSITY UNITED KINGDOM), JAMES D REID (DEPARTMENT BIOSCIENCES DEPARTMENT, UNITED KINGDOM), JOSE A MONREAL (UNIVERSITY OF SEVILLA, BEATRIZ OROSA (DEPARTMENT OF BIOSCIENCES, OF CHEMISTRY, UNIVERSITY OF SHEFFIELD, RAFFAELLA RB BATTAGLIA (DEPARTMENT OF SPAIN), ISABEL RUIZ-BALLESTA (UNIVERSITY DURHAM UNIVERSITY, UNITED KINGDOM), UNITED KINGDOM), PASCAL-ANTOINE CHRISTIN BIOSCIENCES UNIVERSITÀ DEGLI STUDI DI OF SEVILLA, SPAIN), CIRENIA ARIAS-BALDRICH DIEGO ROBLEDO (EDINBURGH UNIVERSITY, (DEPARTMENT OF ANIMAL AND PLANT SCIENCES, MILANO MILAN, ITALY), ARI AS SADANANDOM (UNIVERSITY OF SEVILLA, SPAIN), GUILLERMO UNITED KINGDOM), MARK BAILEY (UNIVERSITY UNIVERSITY OF SHEFFIELD, UNITED KINGDOM) (DURHAM UNIVERSITY BIOSCIENCES DEPARTMENT, BAENA (UNIVERSITY OF SEVILLA, SPAIN), OF BIRMINGHAM, UNITED KINGDOM), ARI UNITED KINGDOM), LUCIO LC CONTI (DEPARTMENT CLARA DE LA OSA (UNIVERSITY OF SEVILLA, SADANANDOM (DEPARTMENT OF BIOSCIENCES, [email protected] OF BIOSCIENCES UNIVERSITÀ DEGLI STUDI DI SPAIN), ANA B FERIA (UNIVERSITY OF SEVILLA, DURHAM UNIVERSITY, UNITED KINGDOM) MILANO MILAN, ITALY) SPAIN), SOFIA GARCIA-MAURIÑO (UNIVERSITY In the C4 photosynthesis pathway, atmospheric CO2 OF SEVILLA, SPAIN), CRISTINA ECHEVARRIA [email protected] enters mesophyll cells and converted to bicarbonate (UNIVERSITY OF SEVILLA, SPAIN) (HCO3 - ). Together HCO3 - and phosphoenolpyruvate [email protected] Posttranslational modification of proteins by small are carboxylated by phosphoenolpyruvate carboxylase During fertilisation, stamen elongation needs to be [email protected] ubiquitin-like modifier (SUMO) is emerging as a (PEPC) to produce oxaloacetate (OAA). The OAA synchronised with pistil growth. The phytohormone key regulator of plant stress responses. In plants, is further converted into malate to release CO2 for gibberellic acid (GA) promotes stamen growth by Phosphoenolpyruvate carboxylase (PEPC) (EC 4.1.1.31) SUMOylation has been implicated in response to fixation by RuBisCo in the Calvin Cycle. PEPC plays stimulating the degradation of growth repressing is a ubiquitous cytosolic enzyme that catalyses the environmental stresses. The covalent attachment a major role in increasing the concentration of CO2 to DELLA proteins. DELLA accumulation is negatively irreversible β-carboxylation of PEP in the presence of of SUMO to target proteins can affect these proteins the point needed to saturate RuBisCo thus inhibiting regulated by GAs through the ubiquitin-proteasome HCO3 - to yield oxaloacetate and Pi. PEPC plays a crucial in different ways: altering their stability, sub-cellular photorespiration. PEPC activity is controlled by system. In Arabidopsis thaliana, a proportion of role in C4 and CAM photosynthesis, where it catalyses localisation or activity. SUMO is removed from reversible phosphorylation at serine residue located DELLAs is also conjugated to the small ubiquitin-like the initial fixation of atmospheric CO2. PEPC also fulfils their target conjugates by SUMO proteases. Two of close to the N-terminal and this reaction is catalysed modifier (SUMO) protein, which stabilizes DELLAs. several important non-photosynthetic functions these SUMO proteases are OVERLY TOLERANT TO by phosphoenolpyruvate carboxylase kinase (PEPCK). Increased DELLA levels occur in the SUMOprotease- including supporting carbon-nitrogen interactions, SALT 1 and 2 (OTS1 and OTS2), which are localised The mechanism of how PEPCK phosphorylate PEPC deficient OVERLY TOLERANT TO SALT 1 and 2 (ots1 seed formation and germination, fruit ripening, guard in the nucleus and act redundantly to control salt with ATP and how phosphorylated PEPC acts as a ots2) double mutants, especially under salt stress cell metabolism, root malate excretion, or provision of stress response in Arabidopsis. To help to bring carboxylase enzyme is still unknown. Thus, the current conditions. Here, we show that OTS genes play a malate for N2 -fixing bacteroids. Due to its pivotal roles understanding to previously observed ots1/2 goal of the research is to obtain biologically active redundant role in the control of plant fertility under in plant metabolism, PEPC protein is tightly regulated phenotypes. We carried out an RNA-seq experiment PEPCK and validate whether it can phosphorylate non-stress conditions. Mutants of ots1 ots2 display by post-translational modifications (PTMs). PEPC is on Arabidopsis thaliana wildtype and ots1/ots2 double PEPC or not. Therefore, DNA fragment encoding reduced fertility compared with the wild type, owing phosphorylated in a conserved Ser residue producing mutant plants in basal condition and in response to C4 PEPCK from Panicum queenslandica was cloned to reduced stamen elongation. Stamen growth, an activation of the enzyme. C4 PEPC is inhibited by Salicylic Acid (SA) and Jasmonic Acid (JA) treatment. in-frame into pET-44a over-expression plasmid. pollination rate and seed production are restored in anionic phospholipids and presumably recruited to We found that the transcriptional response PEPCK was over-expressed in E. coli Rosetta and ots1 ots2 della mutants, thus linking OTS1 function to the membrane, in a manner independent from the initially is composed of a core set of multi-stress then purified by His6 -affinity chromatography. The the control of DELLA activity in the context of filament phosphorylation state of the enzyme. Regulatory responsive genes and becomes increasingly stress in vitro phosphorylation assay was carried out by elongation. OTS levels appear to be developmentally PEPC monoubiquitination has been demonstrated specific as time progresses. Furthermore we report the incubating 0.1 µg/µl PEPC with 0.02µg/µl PEPCK regulated as OTS1/2 transcript upregulation in castor oil seeds, developing proteoid roots of harsh identification of many of the core genes differentially with or without ATP for 120 min at 30°C and it was during stamen development overlaps with GAs hakea, and in lily pollen. Recently we have showed that regulated in ots1/2 background. Finally, since found that PEPC was phosphorylated by PEPCK from accumulations. We propose that OTS genes enable PEPC from sorghum seeds, and in sorghum roots under SUMOylation is a post-transcriptional modification, Pro-Q® Diamond phosphoprotein gel stain. Further synchronisation of stamen development by facilitating ammonium toxicity, is monoubiquitinated and that we looked for enriched TF sites in the promoters of the works will be involve separating phosphorylated PEPC DELLA degradation at a specific developmental stage. this process is inhibitory. In addition, photosynthetic differentially expressed genes to find SUMOylated from non-phosphorylated PEPC and determination of PEPC is S-nytrosilated and/or carbonylated under salt transcription factors. Several TF sites were enriched the sensitivity of phosphorylated PEPC to be inhibited stress conditions. Carbonylation inactivates C4 PEPC among our differentially expressed genes and we have by malate and activation by glucose-6-phosphate while nytrosilation has little impact on its activity but experimentally proved that they are SUMOylated by kinetic assay. The PEPCK structure also will be holds back carbonylation. Moreover, recent results in vivo. Our results provide mechanistic insight visualised at the atomic level through crystallography. suggest that photosynthetic PEPC can be tyr-nitrated into the phenotypes observed in SUMO proteases in a specific residue yielding an inhibited enzyme. defective Arabidopsis mutants and also contribute to Interestingly, most of these PTMs can coexist in the understanding the role of SUMO in response to stress. same protein. The high variety of modifications makes PEPC an ideal model for the study of PTMs in plants. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 50 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 51

C S 17.7 3 FIFTY SHADES OF SUMO: C S 17.74 EXPLOITING PROTEIN jasmonate (JA) analogue that counteracts SA signalling. proteomics we are identifying serine hydrolases in ITS ROLE IN IMMUNITY AND AT MODIFICATION SYSTEMS TO BOOST However, it remains unknown if cross talk between the plants that are sensitive to known inhibitors of de-S- THE FULCRUM OF GROWTH-DEFENCE CROP PRODUCTIVITY: SUMO IN SA and JA signalling pathways impacts the effectiveness acylation. We have shown that we can deliver these of reactive oxygen/nitrogen species, including nitric inhibitors into plants and that they can inhibit plant BALANCE THE FOCUS oxide (NO). NO is extensively involved in shaping serine hydrolase activities in vivo. Furthermore, several hormonal signalling during immunity. NO bioactivity de-S-acylating inhibitors can cause an abnormal MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 is mediated by protein S-nitrosylation, i.e. the covalent root hair phenotype when applied to growing roots. attachment of a NO moiety to reactive thiol groups of FENELLA CROLEY (DURHAM UNIVERSITY, UNITED REBECCA GWYTHER (DURHAM UNIVERSITY, UNITED proteins, forming a protein-SNO modification. Recently, KINGDOM), VIVEK VERMA (DURHAM UNIVERSITY, KINGDOM), EMMA GARRIDO (DURHAM UNIVERSITY, the denitrosylation activity of S-nitrosoglutathione UNITED KINGDOM), ARI SADANANDOM (DURHAM UNITED KINGDOM), ARI SADANANDOM (DURHAM reductase (GSNOR) and thioredoxin-h5 (TRX-h5) C S 17.7 7 IP-MS IDENTIFIES UNIVERSITY, UNITED KINGDOM) UNIVERSITY, UNITED KINGDOM) has been reported to determine fate and amplitude A MEMBRANE RECEPTOR OF THE of SA-mediated immune responses by impacting ARABIDOPSIS GET PATHWAY [email protected] [email protected] specific branches of protein-SNO signalling. By using genetic and biochemical approaches, here we provide MONDAY 11 DECEMBER 2017 The sessile nature of plants requires them to cope with The posttranslational modification system is evidence that Psm-produced coronatine targets an ever-changing environment. Effective adaptive important in enabling plants to adapt to their specific protein-SNO branches in an unexpected LISA ASSECK (ZMBP TUEBINGEN, GERMANY) responses require sophisticated cellular mechanisms environment. During the processes of domestication fashion to wear down the host immune system at post-transcriptional and -translational levels. Post- and breeding, plants were selected for various yield and and promote disease. We propose a model in which [email protected] translational modification by Small Ubiquitin-like adaptational characteristics. The posttranslational disease resistance/susceptibility is determined by a Modifier (SUMO) proteins is emerging as a key player modifier SUMO is known to have a role in the molecular battle between host and pathogen to offset Type II tail-anchored membrane (TA) proteins in these adaptive responses. SUMO conjugation can regulation of a number of these characteristics. Using the equilibrium of interchangeable NO donor species are involved in diverse cellular processes such rapidly change the overall fate of target proteins by bioinformatics, we mined the genomes of cereal and that ultimately determines specificity in the NO- as cell signalling, vesicle trafficking and protein altering their stability or interaction with partner Brassica crops and their non-crop relatives Arabidopsis mediated post-translational control of plant immunity. translocation. Their correct biogenesis including proteins or DNA. SUMOylation entails an enzyme thaliana and Brachypodium dystachon for ULP SUMO membrane insertion, however, is a challenging task for cascade that leads to the activation, conjugation and proteases sequences. We discovered the SUMO system the cell: Lack of N-terminal signal sequences prevents ligation of SUMO to lysine residues of target proteins. in cereal crops is disproportionately elaborate in insertion via the co-translational SRP/SEC61 pathway In addition to their SUMO processing activities, SUMO comparison to B. dystachon. We use this data to propose C S 17.76 DISCOVERING DE-S- while at the same time the C-terminal transmembrane proteases also possess de-conjugative activity capable deSUMOylation as a mechanism for specificity in the ACYLATING ENZYMES IN ARABIDOPSIS domain necessitates chaperone action to prevent of cleaving SUMO from target proteins providing SUMO system. aggregation in the hydrophilic environment of the reversibility and buffering to the pathway. These cytosol. Such TA proteins are post translationally proteases play critical roles in maintaining SUMO MONDAY 11 DECEMBER 2017 targeted into the ER membrane via the Guided machinery in equilibrium. We hypothesise that Entry of Tail-anchored Proteins (GET) pathway that SUMO proteases provide the all-important substrate C S 17.7 5 PROTEIN S-NITROSYLATION MAIJU A LAURILA (UNIVERSITY OF DUNDEE, UNITED KINGDOM), PIERS A HEMSLEY was previously described in mammals and yeast. specificity within the SUMO system. Furthermore, IN IMMUNE-INDUCED HORMONAL (UNIVERSITY OF DUNDEE, UNITED KINGDOM) Recently, we identified several GET orthologues we provide an overview of the role of SUMO in plant NETWORKS in Arabidopsis thaliana through in silico analyses, innate immunity. SUMOylation also overlaps with including one of the two membrane receptors, multiple growth promoting and defence-related MONDAY 11 DECEMBER 2017 [email protected] AtGET1, and found a role of the GET pathway in hormone signalling pathways and hence is pivotal for S-acylation is the only reversible lipid-based post- root hair elongation. Additionally, direct in planta maintaining the growth-defence balance. This review LUCAS FRUNGILLO (UNIVERSITY OF EDINBURGH, translational modification of proteins. Even though interaction analysis using immunoprecipitation mass aims to highlight the intricate molecular mechanisms UNITED KINGDOM), STEVEN H SPOEL (UNIVERSITY OF EDINBURGH, UNITED KINGDOM) 24 protein acyl transferases - enzymes that add acyl spectrometry (IP-MS) of AtGET3a-GFP-expressing utilized by SUMO to regulate plant defence and groups onto proteins - are identified and verified in lines identified a potential candidate for the elusive stabilise the growth-defence equilibrium. [email protected] Arabidopsis, the identities and numbers of any plant AtGET2 receptor that we named AtGET3a-interacting de-S-acylating enzymes remain unknown. More than protein 1 (GIP1). This protein is predicted to possess Plant immunity relies on sophisticated hormonal 500 proteins have been suggested to be S-acylated in three transmembrane domains (TMDs) similar to signalling networks tightly associated with intracellular plants and a still unexplored number of these are likely ScGET2 and the mammalian orthologue CAML - a redox changes. In response to the hemibiotrophic to be de-S-acylated as means of regulating localisation feature that survived the evolutionary divergence of bacterial pathogen Pseudomonas syringae (Psm), the and function. It is therefore very probable that one the amino acid sequence. We provide here evidence phytohormone salicylic acid (SA) mediates defence or more families of plant de-S-acylating enzymes that this gene of unknown function might indeed code responses by coordinating fluctuations in the total await their discovery. De-S-acylating enzymes for the previously unidentifiedAt GET2. glutathione (GSH) pool and a marked burst in reactive from mammals and Toxoplasma have previously oxygen/nitrogen species production. To promote been identified by inhibitor-based approaches using virulence, Psm hijacks phytohormone signalling by competitive activity-based protein profiling (cABPP). secreting the phytotoxin coronatine, a highly active By combining cABPP with quantitative SILAC CELL SECTION SYMPOSIUM POSTER ABSTRACTS 52 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 53

CYP1A GENE EXPRESSION DISSECTING THE MOLECULAR version in arf7 revealed that ARF7 controls LR C S 17.7 8 C S 17.7 9 hydropatterning via SUMOylation. C S 17.8 1 ROLE OF PROTEASOMES IN AS A BASIC FACTOR FOR FIPRONIL MECHANISM REGULATING LATERAL NON-SPECIFIC IMMUNE RESPONSE OF TOXICITY IN CASPIAN KUTUM FISH ROOT HYDROPATTERNING MARINE ANNELIDS

MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 C S 17.8 0 DISRUPTION OF N-LINKED MONDAY 11 DECEMBER 2017 PROTEIN GLYCOSYLATION ALTERS RASHID ALIJANI ARDESHIR (KHORAMSHAR NICOLA J LEFTLEY (THE UNIVERSITY OF MARIIA V STANOVOVA (LOMONOSOV MOSCOW NOTTINGHAM, UNITED KINGDOM), BEATRIZ POLYAMINE OXIDASE SIGNALLING UNIVERSITY OF MARINE SCIENCE AND PATHWAY IN ARABIDOPSIS THALIANA STATE UNIVERSITY, RUSSIA), YULIA V LYUPINA TECHNOLOGY, IRAN) OROSA-PUENTE (THE UNIVERSITY OF DURHAM, (KOLTZOV INSTITUTE OF DEVELOPMENTAL BIOLOGY UNITED KINGDOM), DANIEL VON WANGENHEIM OF RUSSIAN ACADEMY OF SCIENCES, RUSSIA) (THE UNIVERSITY OF NOTTINGHAM, UNITED MONDAY 11 DECEMBER 2017 [email protected] KINGDOM), EMILY MORRIS (THE UNIVERSITY [email protected] BARIS UZILDAY (EGE UNIVERSITY, TURKEY), The aim of this study was to assess the effects of OF NOTTINGHAM, UNITED KINGDOM), RAHUL RENGIN OZGUR (EGE UNIVERSITY, TURKEY), Marine invertebrates represent the unique model for fipronil insecticide on the Caspian kutum fish at BHOSALE (THE UNIVERSITY OF NOTTINGHAM, UNITED KINGDOM), JASON BANDA (THE ISMAIL TURKAN (EGE UNIVERSITY, TURKEY), the molecular mechanisms of adaptation research. different levels of biological organisations and to UNIVERSITY OF NOTTINGHAM, UNITED TOMONOBU KUSANO (TOHOKU UNIVERSITY, JAPAN) Polychaetes (annelids, Annelida) compose significant find possible relationship between these biomarkers. KINGDOM), ANTHONY BISHOPP (THE UNIVERSITY part of marine bottom ecosystems. Combination of Different doses of fipronil (65, 130 and 200 mg/kg) OF NOTTINGHAM, UNITED KINGDOM), ARI [email protected] annelids’ anatomical features provides high level were intraperitoneally administered to the fish for SADANANDOM (THE UNIVERSITY OF DURHAM, of adaptive plasticity and enables development 2 weeks. After 7 and 14 days of exposure, alterations N-linked glycosylation occurs in endoplasmic reticulum UNITED KINGDOM), MALCOLM BENNETT (THE of an effective immune (defensive) system. Free in organ-somatic index, tissue and DNA structure, (ER) and is one of the important post translational UNIVERSITY OF NOTTINGHAM, UNITED KINGDOM) cell elements of the coelomic fluid, coelomocytes, oxidative stress and CYP1A gene expression in gill, modifications that are needed for proper folding of constitute the main component of immune system liver, brain and kidney were studied. Determination glycoproteins. However, heavy protein load in ER lumen [email protected] in annelids. Arenicola marina, marine lugworm, is of these parameters in the liver showed that the can prevent proper glycosylation. This can be mimicked common species of cold-water seas intertidal zone. degree of tissue change (DTC), comet tail, superoxide Lateral roots (LR) contribute considerably to the by disruption of N-glycosylation with an antibiotic We investigated the specific features of proteasomes dismutase (SOD) and relative CYP1A mRNA expression architecture of the root system. The hormone auxin named tunicamycin. Accumulation of unfolded proteins and chaperones functioning in A. marina coelomocytes increased mostly in a time dependent manner whereas tightly controls the regulation of LR formation in in ER lumen is called ER stress, which is perceived by during the experimental inflammation. To induce the in the kidney increased mostly in a dose dependent response to environmental signals. For example, roots a complex gene network and their induction triggers inflammation, we injected the coelomic cavity of adult manner. These parameters in the gill increased more have the ability to distinguish between wet and dry unfolded protein response (UPR), increasing protein worms with bacterial cell wall lipopolysaccharide in time and dose dependent manner. Apart from the micro environments in the soil and adapt the positioning folding capacity. Polyamines are low molecular weight (LPS), dissolved in fresh sea water (FSW), in changes in CYP1A expression and oxidative stress, of lateral roots accordingly. This concept is referred to as molecules that function in growth and stress response concentration about 50 ng/ml. The FSW was no alterations were observed in the brain. Multiple LR hydropatterning and is a novel adaptive mechanism in plants. Putrescine, spermidine and spermine are used in control experiments as well. 1 hour after regression analysis showed that the CYP1A had the for controlling root branching. When growing vertically important polyamines and among them spermidine LPS injection the content of proteasome subunits most correlation with the organ-somatic index (R2 = down an agar plate, Arabidopsis thaliana roots are also is known to induce a key transcription factor bZIP60 (including structural α and proteolytic β5 types) 0.76) and comet tail (R2 = 0.89) in the liver, and with exposed to an asymmetric distribution of water that involved in ER stress response. However, information on significantly increases, as well as the proteasomes’ DTC (R2 = 0.93) and oxidative stress (R2 = 0.87) in the causes a meniscus to form around the primary root (PR) effects of disruption of N-linked protein glycosylation chymotrypsin-like activity (CLA). Also a new inducible kidney. Generally, this study showed that CYP1A gene circumference. LRs develop preferentially on the side on polyamine metabolism in plants is not known. form of Hsp70 chaperone appears after LPS injection. expression can be considered as one basic factor for of the PR in contact with water, rather than the side Polyamine oxidases (PAO) catalyse the oxidation of Proteasome complexes of annelid coelomocytes in fipronil toxicity in this fish. However, other possible exposed to air. It has been revealed that the transcription spermidine and spermine and participate in triggering normal conditions are characterised by relatively low factors also should be considered for future research. factor AUXIN RESPONSE FACTOR 7 (ARF7) is essential of stress signalling. Due to this, in this work we have amount of 26S proteasome form. This fact indicates for LR hydropatterning. In contrast to wild type, arf7 investigated the response of different PAO genes (PAO1- the specialisation of annelid proteasome system on loss of function mutants do not exhibit greater LR PAO5) to tunicamycin treatment in Arabidopsis thaliana. non-ubiquitinated proteins hydrolysis. The infection emergence towards the side of the PR in contact with Among these genes only the expression of PAO1 and leads to full dissociation of macromolecular regulatory moisture. Ectopic expression of ARF7 can rescue arf7 PAO5 responded to tunicamycin treatment. In further particles PA700 and PA200. The functional shift LR hydropatterning, implying that ARF7regulates LR experiments, response of pao1, pao5 and pao1/pao5 of coelomocytes proteasome system in conditions hydropatterning via a post-transcriptional mechanism. double mutant to tunicamycin was evaluated in terms of considerable stress leads to implementation of One promising post-transcriptional mechanism that of induction of UPR. For this, expressions of bZIP28, proteolysis only on “pure” 20S proteasomes. This work may control LR hydropatterning involves protein bZIP17, bZIP60, BiP1, BiP3,CNX, ERO1, HRD1, DER1, was partially supported by 16-04-00454-a RFBR grant. SUMOylation (a Small Ubiquitin-like Modifier), SEL1, UBC32, which are involved ER quality control since the SUMO mutant ots1 ots2 phenocopies the and protein degradation, were measured. Overall, we arf7 LR hydropatterning defect. ARF7 is a target for demonstrated that PAO is a key factor for triggering of SUMO modification, containing several SUMOylation UPR in plants. sites including one within its DNA binding domain.

Expressing wild type ARF7 and a non-SUMOylated CELL SECTION SYMPOSIUM POSTER ABSTRACTS 54 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 55

major cytosolic MDH isoform (cytMDH1) is sensitive AN OMICS APPROACH TO C S 17.8 2 UBIQUITINATION IN WHEAT C S 17.8 3 C S 17.8 4 SELF-PROTECTION to H2O2 through sulfur oxidation of cysteines and DEFENCE AGAINST SEPTORIA FUNGUS INVESTIGATE THE EFFECT OF CLIMATE OF ARABIDOPSIS CYTOSOLIC methionines. CytMDH1 oxidation affects the kinetics, CHANGE IN EUCALYPTUS MALATE DEHYDROGENASE AGAINST secondary structure, and thermodynamic stability of MONDAY 11 DECEMBER 2017 OXIDATIVE STRESS cytMDH1. Moreover, mass-spectrometry analyses and MONDAY 11 DECEMBER 2017 comparison of crystal structures between the reduced LINDA MILLYARD (DURHAM UNIVERSITY, and H2O2-treated cytMDH1 further show that a Trx- UNITED KINGDOM), JACK LEE (DURHAM BRUNA MARQUES DOS SANTOS (UNIVERSITY MONDAY 11 DECEMBER 2017 reversible homodimerization of cytMDH1 through UNIVERSITY, UNITED KINGDOM), CUNJIN ZHANG OF COPENHAGEN, DENMARK), CECILIE IDA Cys330 disulfide formation protects the protein from ADNAN KHAN NIAZI (CABB UNIVERSITY OF (DURHAM UNIVERSITY, UNITED KINGDOM), GARY CETTI HANSEN (UNIVERSITY OF COPENHAGEN, overoxidation. Consistently, we found that cytosolic DENMARK), METTE CLAUSEN (UNIVERSITY OF AGRICULTURE FAISALABAD, PAKISTAN), YATES (DURHAM UNIVERSITY, UNITED KINGDOM), thioredoxins interact specifically with cytosolic COPENHAGEN, DENMARK), TAO LI (UNIVERSITY JINGJING HUANG (VIB-UGENT CENTER FOR PLANT ARI SADANANDOM (DURHAM UNIVERSITY, MDH in a yeast two-hybrid system. Importantly, we OF COPENHAGEN, DENMARK), RIIKKA RINNAN SYSTEMS BIOLOGY, BELGIUM), DAVID YOUNG UNITED KINGDOM) also show that cytosolic and chloroplastic, but not (UNIVERSITY OF COPENHAGEN, DENMARK), (VIB-VUB CENTER FOR STRUCTURAL BIOLOGY BIRGER LINDBERG MØLLER (UNIVERSITY 1050 BRUSSELS, BELGIUM), LEONARDO ASTOL mitochondrial NAD-MDH activities are sensitive to [email protected] OF COPENHAGEN, DENMARK), ELIZABETH ROSADO (VIB-VUB CENTER FOR STRUCTURAL H2O2 stress in Arabidopsis. NAD-MDH activities are BIOLOGY 1050 BRUSSELS, BELGIUM), DIDIER decreased both in a catalase2 (cat2) mutant and a NADP Wheat is a major food crop for much of the world, HEATHER JAKOBSEN NEILSON (UNIVERSITY OF VERTOMMEN (DE DUVE INSTITUTE UNIVERSITÉ thioredoxin reductase mutant (ntra ntrb), emphasizing and with an ever-increasing population there is a COPENHAGEN, DENMARK) CATHOLIQUE DE LOUVAIN 1200 BRUSSELS, the importance of the thioredoxin reducing system to rising demand to produce more food in a smaller area. BELGIUM), NANDITA BODRA (VIB-UGENT CENTER protect MDH from oxidation in vivo. We propose that the Zymopseptoria tritici is a devastating foliar pathogen [email protected] FOR PLANT SYSTEMS BIOLOGY 9052 GHENT, redox switch of MDH activity contributes to adapt the of wheat, which can lead to a 20% reduction in yield. The Eucalyptus genus is composed of long-lived trees BELGIUM), MOHAMED RAGAB ABDELGAWWAD cell metabolism to environmental constraints. Plants have had to evolve a multitude of different that produce a plethora of specialized metabolites to (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES defence mechanisms due to their sessile nature. interact with their environment and to combat biotic and PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA Protein modifications, such as ubiquitination, abiotic stress. Very little is known about how specialised PERPIGNAN, FRANCE), FLORENCE VIGNOLS have been shown to be central to plant defence. (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES metabolism is regulated in response to climatic changes. In this study, Virus Induced Gene Silencing (VIGS) PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA Therefore, this research project aims to examine the was used to investigate Triticum aestivumE2 ubiquitin PERPIGNAN, FRANCE), BO WEI (VIB-UGENT phenomic, metabolomic and proteomic changes in conjugating (TaU) enzymes. The main focus of this CENTER FOR PLANT SYSTEMS BIOLOGY 9052 Eucalyptus leaves in response to enhanced temperature study is TaU4, the E2 function of which has been proven GHENT, BELGIUM), KHADIJA WAHNI (VIB- and atmospheric CO2 concentration. Eucalyptus through ubiquitin charging assays and the active site VUB CENTER FOR STRUCTURAL BIOLOGY 1050 grandis and E. cladocalyx seedlings were grown in cysteine identified. The possible function of TaU4 BRUSSELS, BELGIUM), TALAAT BASHANDY growth chambers subjected to elevated atmospheric in the Septoria-wheat interaction was investigated (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES CO2 concentration (550 ppm), increased temperature after silencing TaU4 in wheat and then infecting with PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA (30 ºC) and a combination of both factors for eight weeks. Septoria. TaU4 silenced wheat leaves showed a delay PERPIGNAN, FRANCE), LAETITIA BARIAT Photosynthesis, biomass and volatile profile were (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES in the onset of Septoria infection symptoms and had assessed at the end of the growth period. No significant PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA reduced pycnidia and spore counts when compared to response to treatments was detected in total biomass PERPIGNAN, FRANCE), FRANK VAN BREUSEGEM the vector only control. It was concluded that TaU4 or nitrogen content, and we hypothesize that the extra (VIB-UGENT CENTER FOR PLANT SYSTEMS acts as a negative regulator of defence in wheat against carbon is allocated to specialised metabolites, including BIOLOGY 9052 GHENT, BELGIUM), JORIS Septoria fungal infection. volatile organic compounds (VOCs). We identified 64 MESSENS (VIB-VUB CENTER FOR STRUCTURAL biogenic VOCs emitted from leaves. Chemometrics BIOLOGY 1050 BRUSSELS, BELGIUM), JEAN- analysis revealed changes in the volatile emission PHILIPPE REICHHELD (LABORATOIRE GÉNOME profile in response to treatment and key molecular ET DÉVELOPPEMENT DES PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA PERPIGNAN, FRANCE) markers were identified, such as isoprene,p -cymene, and linalool. High temperature is the most prominent factor, resulting in the increase of isoprene emission in [email protected] E. cladocalyx by 2 fold. Proteomics analysis is currently Plant malate dehydrogenase (MDH) isoforms are being undertaken to examine the relationship between found in different cell compartments and function specialised metabolites, photosynthesis and carbon in key metabolic pathways. It is well known that assimilation pathways. Changes in Eucalyptus chemical the chloroplastic NADP-dependent MDH activity and physical parameters may affect the downstream is strictly redox regulated and controlled by light. food chain and feeding habits of herbivores, such as the However, redox-dependence of other NAD-dependent iconic koala. MDH isoforms have been less studied. Here, we show by in vitro biochemical characterisation that the CELL SECTION SYMPOSIUM POSTER ABSTRACTS 56 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 57

including siRNA and miRNA. Arabidopsis thaliana activated protein kinases control the activation of C S 17.8 5 IDENTIFYING AND C S 17.8 6 THE siRNA SUPPRESSOR RTL1 IS REDOX-REGULATED THROUGH encodes nine RNase III: four DICER-LIKE (DCL) and five guard cell anion channels in response to elevated CO2 CHARACTERISING SUBSTRATES RNASE THREE LIKE (RTL). To better understand the concentration. Arabidopsis thaliana mutants for the OF THE IMMUNE KINASE BIK1 GLUTATHIONYLATION OF A CONSERVED CYSTEINE IN THE DOUBLE-STRANDED- molecular functions of RNase III in plants we developed central phosphatases and kinases involved in causing RNA-BINDING DOMAIN a biochemical assay using RTL1 as a model. We show alterations in stomatal movements have been isolated. MONDAY 11 DECEMBER 2017 that RTL1 does not degrade dsRNA randomly, but We are crossing these mutations into plants with high recognizes specific duplex sequences to direct accurate stomatal density to create multiple mutant plants MONDAY 11 DECEMBER 2017 THOMAS A DEFALCO (THE SAINSBURY LABORATORY, cleavage. Furthermore, we demonstrate that RNase III which have high numbers of ABA-hypersensitive, UNITED KINGDOM), SHUSHU JIANG (THE and dsRNA binding domains (dsRBD) are both required but CO2 -insensitive stomata. These plants should SAINSBURY LABORATORY, UNITED KINGDOM), ADNAN KHAN NIAZI (CABB UNIVERSITY OF for dsRNA cleavage. Interestingly, the four DCL and have high photosynthetic levels at future elevated LENA STRANSFELD (THE SAINSBURY LABORATORY, AGRICULTURE FAISALABAD, PAKISTAN), the three RTL that carry dsRBD share a conserved CO2 concentrations if water is not limiting, but will be UNITED KINGDOM), CYRIL ZIPFEL (THE SAINSBURY CYRIL CHARBONNEL (LABORATOIRE GÉNOME cysteine (C230 in Arabidopsis RTL1) in their dsRBD. able to respond efficiently to drought conditions by LABORATORY, UNITED KINGDOM) ET DÉVELOPPEMENT DES PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA PERPIGNAN, FRANCE), C230 is essential for RTL1 and DCL1 activities and is stomatal closure and water preservation. As stomatal subjected to post-transcriptional modification. Indeed, signalling pathways are highly conserved, we propose [email protected] EMILIE ELVIRA-MATELOT (INSTITUT JEAN- PIERRE BOURGIN UMR1318 INRA AGROPARISTECH under oxidizing conditions, glutathionylation of C230 that a similar approach could be used to improve crop Pathogen-associated molecular patterns (PAMPs) are CNRS UNIVERSITÉ PARIS-SACLAY VERSAILLES, inhibits RTL1 cleavage activity in a reversible manner water use efficiency in the future. recognised by plant cell-surface pattern recognition FRANCE), ELŻBIETA NOWAK (LABORATORY OF involving glutaredoxins. We conclude that the redox receptors (PRRs), leading to pattern-triggered PROTEIN STRUCTURE INTERNATIONAL INSTITUTE state of the dsRBD ensures a fine-tune regulation of immunity (PTI). The cytoplasmic kinase BIK1 is OF MOLECULAR AND CELL BIOLOGY WARSAW, dsRNA processing by plant RNase III. C S 17.8 8 CHARACTERISATION OF an immediate substrate for many activated PRR POLAND), MATTHIAS ZYTNICKI (UMIAT INRA THE N-TERMINAL ACETYLATION complexes, and regulates multiple cellular outputs, UR-875 F-31326 CASTANET-TOLOSAN, FRANCE), BRANCH OF THE N-END RULE PATHWAY wherein it acts as a convergent executor of immune ANNE DE BURES (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES PLANTES UNIVERSITÉ C S 17.8 7 IMPROVEMENT OF PLANT OF PROTEIN DEGRADATION IN signalling. Despite this central role, the protein WATER USE EFFICIENCY VIA substrates of BIK1 are poorly characterised. Previous PERPIGNAN VIA DOMITIA PERPIGNAN, FRANCE), ARABIDOPSIS THALIANA work identified the NADPH oxidase RBOHD as one EDOUARD JOBET (LABORATOIRE GÉNOME ET MODIFICATION OF STOMATAL such substrate, directly linking BIK1 activation to DÉVELOPPEMENT DES PLANTES UNIVERSITÉ SIGNALLING PATHWAYS MONDAY 11 DECEMBER 2017 PERPIGNAN VIA DOMITIA PERPIGNAN, FRANCE), apoplastic reactive oxygen species (ROS) production, a ALISSON OPSOMER (6LABORATOIRE DE SPECTROM´ hallmark of PTI responses. Further work has identified MONDAY 11 DECEMBER 2017 MARK BAILEY (UNIVERSITY OF BIRMINGHAM, ETRIE DE MASSE BIOORGANIQUEUNIVERSITÉ DE 22 additional putative BIK1 substrates, which include UNITED KINGDOM), ADRIENNE C PAYNE STRASBOURG CNRS STRASBOURG, FRANCE), NAHID several plasma membrane-localised transporter and/ HANNA HÕRAK (UNIVERSITY OF SHEFFIELD, (UNIVERSITY OF BIRMINGHAM, UNITED KINGDOM), SHAMANDI (INSTITUT JEAN-PIERRE BOURGIN OLUWATUNMISE AKINTEWE (UNIVERSITY OF or signalling proteins. We are investigating the roles of UNITED KINGDOM), LUKE FOUNTAIN (UNIVERSITY UMR1318 INRA AGROPARISTECH CNRS UNIVERSITÉ BIRMINGHAM, UNITED KINGDOM), DANIEL J GIBBS these putative BIK1 substrates in immune signalling. OF SHEFFIELD, UNITED KINGDOM), JULIE E GRAY PARIS-SACLAY VERSAILLES, FRANCE), MARCIN (UNIVERSITY OF SHEFFIELD, UNITED KINGDOM) (UNIVERSITY OF BIRMINGHAM, UNITED KINGDOM) Results from this work will further elucidate the NOWOTNY (LABORATORY OF PROTEIN STRUCTURE hitherto unresolved molecular components linking INTERNATIONAL INSTITUTE OF MOLECULAR AND [email protected] [email protected] ligand-induced PRR activation to downstream CELL BIOLOGY WARSAW, POLAND), CHRISTINE signalling outputs associated with plant immunity. CARAPITO (LABORATOIRE DE SPECTROMÉTRIE Increasing atmospheric CO2 concentrations are Regulating a diverse range of essential processes DE MASSE BIOORGANIQUEUNIVERSITÉ DE affecting plant growth and behaviour around the in eukaryotes, the N-end rule pathway is a highly STRASBOURG CNRS STRASBOURG, FRANCE), globe. Stomata control gas exchange between plants conserved division of the ubiquitin proteasome JEAN-PHILIPPE REICHHELD (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES PLANTES and their environment, and by balancing CO2 uptake for system that controls protein stabilities within UNIVERSITÉ PERPIGNAN VIA DOMITIA photosynthesis and water loss via transpiration, they cells dependent on their N-terminal (Nt) identity. PERPIGNAN, FRANCE), HERVÉ VAUCHERET ensure plant survival and growth. These pores in the Recent studies have identified a novel branch of the (INSTITUT JEAN-PIERRE BOURGIN UMR1318 INRA leaf epidermis are formed of specialised guard cells, and pathway that specifically degrades N-terminally AGROPARISTECH CNRS UNIVERSITÉ PARIS-SACLAY open and close in response to changes in environmental acetylated proteins - the Ac/N-end rule pathway. In VERSAILLES, FRANCE), JULIO SAEZ-VASQUEZ conditions through changes in intracellular ion yeast and mammals, this pathway plays a key role (LABORATOIRE GÉNOME ET DÉVELOPPEMENT DES concentrations. The plant stress hormone abscisic acid in regulating protein-complex homeostasis, peptide PLANTES UNIVERSITÉ PERPIGNAN VIA DOMITIA (ABA) and elevated CO2 concentration are key triggers quality control and signal transduction. At present PERPIGNAN, FRANCE) of stomatal closure. ABA triggers a signalling cascade, we do not know if the pathway exists in plants. where protein phosphatases and kinases control the Degradation via the Ac/N-end rule involves two activation of ion channels leading to stomatal closure. key steps: (1) Nt-acetylation by Nt-acetyltransferases [email protected] The same post-translational protein modifications also (NATs), and (2) recognition of Nt-acetylated proteins RNase III enzymes cleave double stranded (ds)RNA. contribute to CO2 -induced stomatal closure. However, and subsequent polyubiquitination by specific E3 This is an essential step for regulating the processing recently a CO2 -specific pathway was identified ubiquitin ligases (Ac/N-recognins, to date NOT4 and of mRNA, rRNA, snoRNA and other small RNAs, where, independently of ABA signalling, mitogen- DOA10/TEB4). Several NATs have been previously CELL SECTION SYMPOSIUM POSTER ABSTRACTS 58 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 59

characterised in plants, and we have identified putative on this, our main working hypothesis suggests that as well as other PR proteins, peroxidases, kinases, oxidases and a successful defence response. Overall, homologues of both NOT4 and DOA10 in the Arabidopsis BPS1 either polyubiquitinates negative regulator(s) leucine-rich repeat (LRR) containing proteins, and our results reveal a novel mechanism of G6PD adaptive thaliana genome. In contrast to animals and yeast, of PTI leading to its subsequent degradation by hormone and cell wall biosynthesis proteins. Many regulation. We provide evidence that ASKα and G6PD6 Arabidopsis encodes for multiple copies of these E3s, proteasome or activates positive regulator(s) of PTI of these are likely to be involved in protein post- constitute a signalling module that links protein suggesting potential divergence of function. Here we through different type of ubiquitination mark. Now, translational modifications, reactive oxygen species phosphorylation cascades to metabolic adjustment present our data on the functional characterisation of we are looking for potential BPS1 substrates and the production, and other plant-pathogen responses. under both abiotic and biotic stress conditions. the plant Ac/N-recognins, and identification of their latest findings will be presented during the meeting. We predict that some of the identified EHM specific putative substrates in Arabidopsis using a combination Via characterization of BPS1 function in PTI, we aim proteins are putative key players of the host-biotroph of yeast and plant molecular genetics and protein to improve our understanding of how activated PRR interaction, where they may be acting as susceptibility biochemistry. complexes regulate downstream immune signalling, factors, or playing a role in resistance. C S 17.9 2 IDENTIFICATION OF NO which is a very important question in innate immunity, GAMETOPHORES 1 (PPNOG1), A NOVEL in both plants and mammals. REGULATOR OF THREE-DIMENSIONAL C S 17.8 9 DYNAMIC INTERPLAY GROWTH IN PHYSCOMITRELLA PATENS BETWEEN PHOSPHORYLATION AND C S 17.9 1 PHOSPHORYLATION- MEDIATED STRESS SIGNALLING UBIQUITINATION DURING PLANT C S 17.9 0 IDENTIFICATION OF MONDAY 11 DECEMBER 2017 RECEPTOR KINASE-MEDIATED BARLEY EXTA-HAUSTORIAL MEMBRANE AND REDOX REGULATION IMMUNITY PROTEINS IN THE HAUSTORIA OF LAURA A MOODY (UNIVERSITY OF OXFORD, UNITED THE OBLIGATE BIOTROPHIC FUNGAL MONDAY 11 DECEMBER 2017 KINGDOM), STEVE KELLY (UNIVERSITY OF OXFORD, UNITED KINGDOM), ESTER RABBINOWITSCH MONDAY 11 DECEMBER 2017 PATHOGEN, BLUMERIA GRAMINISS HANSJÖRG STAMPFL (CENTER FOR HEALTH (UNIVERSITY OF OXFORD, UNITED KINGDOM), F.SP HORDEI JANE A LANGDALE (UNIVERSITY OF OXFORD, MARIA DERKACHEVA (THE SAINSBURY BIORESOURCES, AUSTRIAN INSTITUTE OF UNITED KINGDOM) LABORATORY, NORWICH RESEARCH PARK, TECHNOLOGY, AUSTRIA), SILVIA DAL SANTO MONDAY 11 DECEMBER 2017 NORWICH, UNITED KINGDOM), SHUSHU JIANG (GREGOR MENDEL INSTITUTE OF MOLECULAR [email protected] (THE SAINSBURY LABORATORY, NORWICH PLANT BIOLOGY, AUSTRIA), CLAUDIA JONAK SEBASTIEN LH LAMBERTUCCI (ROYAL HOLLOWAY RESEARCH PARK, NORWICH, UNITED KINGDOM), (CENTER FOR HEALTH BIORESOURCES, AUSTRIAN UNIVERSITY OF LONDON, UNITED KINGDOM), Multicellular eukaryotes exhibit 3-dimensional (3D) PAUL DERBYSHIRE (THE SAINSBURY LABORATORY, INSTITUTE OF TECHNOLOGY, AUSTRIA) LAURENCE V BINDSCHEDLER (ROYAL HOLLOWAY body plans that result from the elaboration of two NORWICH RESEARCH PARK, NORWICH, UNITED UNIVERSITY OF LONDON, UNITED KINGDOM) or three growth axes. Although studies in a range KINGDOM), LENA STRANSFELD (THE SAINSBURY [email protected] of organisms have investigated the mechanisms LABORATORY NORWICH RESEARCH PARK, underpinning the establishment of individual axes, NORWICH, UNITED KINGDOM), FRANK MENKE (THE [email protected] Unfavourable environmental conditions and pathogen we have little understanding of how 3D growth SAINSBURY LABORATORY, NORWICH RESEARCH infections limit plant growth and development and thus Diseases attributed to fungal pathogens are major per se is initiated. In flowering plants the onset of PARK, NORWICH, UNITED KINGDOM), CYRIL reduce fitness. Plants have evolved complex cellular contributors to reduction in crop yield, including 3D growth occurs within the first divisions of the ZIPFEL (THE SAINSBURY LABORATORY, NORWICH and physiological mechanisms to prevent damage and Blumeria graminis, the causal agent of barley powdery fertilized zygote. As such, it is virtually impossible RESEARCH PARK, NORWICH, UNITED KINGDOM) ensure growth under stress conditions. These responses mildew. This fungus is an obligate biotrophic pathogen to genetically dissect the underlying mechanisms are controlled by various stress-type specific but also producing haustorial feeding structures, which because mutants would be embryo lethal and [email protected] common and interacting signalling pathways. Protein are required for infection and are located within a compromised switch to 3D growth would be phosphorylation and reactive oxygen species (ROS) The first layer of plant immunity is mediated by the the host epidermis,. Over 500 secreted Blumeria difficult to distinguish from many other causes of constitute two integral components of cellular stress recognition of conserved microbial features known effector candidates (BECs) have been predicted, lethality. In early divergent plant lineages such as signalling. In our work, we identified theArabidopsis as pathogen-associated molecular patterns (PAMPs) many of which were identified as haustoria specific the mosses, however, the production of 3D shoots GSK3/Shaggy-like protein kinase ASKα as a positive by plasma membrane-localized pattern recognition proteins. Eight BECs were shown to be essential is often preceded by an extended 2D growth phase. regulator of both abiotic and biotic stress responses. Salt receptors (PRRs). It leads to PAMP-triggered immunity for infection. However there is sparse information Using UV-induced mutagenesis, we generated stress and pathogen infection enhance ASKα activity, (PTI) that restricts the multiplication of most potential about the plant derived extra-haustorial membrane mutants in Physcomitrella patens that failed to which in turn phosphorylates the cytosolic glucose pathogens. An immediate downstream substrate of (EHM) which surrounds the haustorial structure. initiate 3D growth and devised a novel strategy to 6-phosphate dehydrogenase isoform G6PD6. G6PD is activated PRR complexes is the cytoplasmic kinase Haustoria and their associated EHM structures map the causative mutations. The strategy is based the key enzyme of the oxidative pentose phosphate BIK1, which positively regulates PTI signalling were isolated to characterise their specific on genome-wide bulk segregant analysis of progeny pathway providing reducing equivalents in the form triggered by several PAMPs. However, the BIK1 proteomes using a differential approach. Proteins derived from somatic hybrids that were generated of NADPH. Stress-activated ASKα phosphorylates downstream targets are mostly unknown. Here, we were extracted and precipitated in TCA-acetone. between polymorphic lines. This innovative approach G6PD6 on the conserved threonine site Thr-467, identified a new BIK1 phosphorylation substrate Tryptic peptides were analysed by nLC-nESI/MSMS. enabled us to determine that a 3D-defective mutant thereby enhancing its enzymatic activity. Remarkably, (BPS1), which is an E3 ubiquitin ligase. BPS1 interacts A total of 185 barley proteins were found exclusively phenotype was caused by the introduction of a while under salt stress conditions, enhanced G6PD with BIK1 in vivo and is phosphorylated by BIK1 in vitro. to the EHM in the enriched haustoria fraction, being premature termination codon in the No Gametophores 1 activity contributes to the removal of excess levels Moreover, it associates with FLS2 and BAK1 upon flg22 absent in the infected epidermis sample. Included (PpNOG1) gene, which encodes a ubiquitin-associated of ROS via the ascorbate/glutathione cycle and thus treatment. The preliminary genetic data suggest that within these were pathogenesis related proteins, protein. PpNOG1 overexpression restored 3D growth stress tolerance, upon pathogen recognition G6PD BPS1 is a positive regulator of plant immunity. Based such as PR5, a known interactor with BEC1054, to the mutant confirming correct gene identification. activity is necessary for ROS production by NADPH CELL SECTION SYMPOSIUM POSTER ABSTRACTS 60 CELL SECTION SYMPOSIUM POSTER ABSTRACTS 61

C S 17.9 3 PROTEASOME-ASSOCIATED C S 17.9 4 INSECTICIDAL C S 17.9 5 PHOSPHOPROTEOMIC C S 17.9 6 N-TERMINAL PEPTIDE HECT-TYPE UBIQUITIN LIGASE FUSION PROTEINS: HOW DOES APPROACH TO SURVEY MOLECULAR ENRICHMENT AS A TOOL FOR STUDYING ACTIVITY IS REQUIRED FOR THE ORIENTATION OF THE TOXIN COMPONENTS OF PLANT IMMUNE TARGETED PROTEIN DEGRADATION PLANT IMMUNITY TO THE CARRIER AFFECT TOXICITY SYSTEM PATHWAYS AND PROTEOLYTIC EVENTS TO INSECTS? MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 MONDAY 11 DECEMBER 2017 HEATHER GREY (UNIVERSITY OF EDINBURGH, HIROFUMI NAKAGAMI (MAX PLANCK INSTITUTE FREDERICA L THEODOULOU (ROTHAMSTED UNITED KINGDOM), JAMES J FURNISS BECKY E S MORRELL (DURHAM UNIVERSITY, FOR PLANT BREEDING RESEARCH, GERMANY), RESEARCH, UNITED KINGDOM), HONGTAO ZHANG (UNIVERSITY OF EDINBURGH, UNITED KINGDOM), UNITED KINGDOM), PRASHANT PYATI (DURHAM HIDENORI MATSUI (CSRS RIKEN, JAPAN), IZUMI (ROTHAMSTED RESEARCH, UNIVERSITY OF LORNA JACKSON (UNIVERSITY OF EDINBURGH, UNIVERSITY, UNITED KINGDOM), JOHN YOTSUI (CSRS RIKEN, JAPAN), HIDEKAZU CAMBRIDGE, UNITED KINGDOM), MICHAEL J DEERY UNITED KINGDOM), CATRIONA MCINTOSH GATEHOUSE (DURHAM UNIVERSITY, UNITED IWAKAWA (MAX PLANCK INSTITUTE FOR PLANT (UNIVERSITY OF CAMBRIDGE, UNITED KINGDOM), (UNIVERSITY OF EDINBURGH, UNITED KINGDOM), KINGDOM), ELAINE FITCHES (DURHAM BREEDING RESEARCH, GERMANY), GANG-SU HYON LUCY GANNON (ROTHAMSTED RESEARCH, UNITED YASUOMI TADA (NAGOYA UNIVESITY, JAPAN), UNIVERSITY, UNITED KINGDOM) (CSRS RIKEN, JAPAN), YUKO NOMURA (CSRS KINGDOM), KIRSTY L HASSALL (ROTHAMSTED STEVEN H SPOEL (UNIVERSITY OF EDINBURGH, RIKEN, JAPAN), RYUICHI NISHIHAMA (KYOTO RESEARCH, UNITED KINGDOM), KATHRYN S LILLEY UNITED KINGDOM) [email protected] UNIVERSITY, JAPAN), TAKAYUKI KOHCHI (KYOTO (UNIVERSITY OF CAMBRIDGE, UNITED KINGDOM) UNIVERSITY, JAPAN) There are increasing demands being placed on food [email protected] [email protected] production to feed the growing population. Insecticidal [email protected] Proteolytic degradation is important for the bulk In response to infection transcription factors play control is a vital component to increase food supply, During the last several decades, extensive analyses removal of damaged or unwanted proteins but a central role in the immune response through however there is increasing resistance developing in revealed that plants utilize a two-branched immune specific proteolytic cleavage represents a pervasive extensive transcriptional reprogramming. In plants, pest species. Additionally, effective insecticides are system for defence against pathogens. In the first and irreversible post-translational modification that the pathogen-induced immune hormone salicylic being removed from the market due to toxicity to the branch, transmembrane pattern recognition can alter the fate and function of a given protein. One acid (SA) activates the transcriptional coactivator environment and pollinator species. A new fusion receptors (PRR) are used to recognise and respond example of this is the Arg/N-end rule pathway of NPR1, resulting in activation of immune response protein has been developed that utilises Snowdrop to slowly evolving pathogen-associated molecular targeted protein degradation, which links the half- genes. Ongoing stimulation of gene expression lectins (Galanthus nivalisagglutinin; GNA), which when patterns (PAMP). In the second branch, either a direct life of a protein to the identity of its amino (N-) terminal requires continuous instability of NPR1 at target fed orally is transported across the gut epithelium to the or an indirect recognition of the pathogen through residue. Proteins become substrates for the pathway gene promoters through its ubiquitin-dependent haemolymph of insects, however this carrier has little disease-resistance (R) proteins is used for response to following proteolytic cleavage that may be followed proteasomal degradation. However, the factors insecticidal toxicity. The toxicity can be increased by pathogen virulence factors. While extensive genetic by enzymatic modification including oxidation and involved in regulation of NPR1 transcriptional activity fusion to the spider-venom peptide ω-hexatoxin-Hv1a screens successfully identified a number of PRRs and arginylation to produce novel N-termini. These new are not fully understood. Here, we show that three (Hv1a) from the Funnel web spider (Hadronyche versuta). components which affect abundance and maturation N-termini can act as signals (degrons) for recognition members of the HECT domain containing family of E3 This peptide specifically targets insect’s voltage- of PRRs, signal transduction mechanisms that lead to by specific E3 ligases and subsequent degradation via ligases, UPL1, UPL3 and UPL5 are required for NPR1- gated calcium channels in the central nervous system defence responses is thus far limited. This partly stems the 26S proteasome. We will discuss the pros and cons dependent gene activation. Disruption of these UPL however, when fed on its own orally, has little toxic effect from limitations of forward genetics caused by lethality of N-terminal peptide enrichment by Terminal Amine ligases renders plants insensitive to SA and susceptible on Mamestra brassicae (cabbage moth) larvae and the and/or genetic redundancy. Accordingly, we have been Isotope Labelling of Substrates (TAILS) as a means to infection. Disruption of UPL3 resulted in an overall aphid species Acyrthosiphon pisum (Pea), Sitobion avenae taking phosphoproteomic approach to understand the to identify potential substrates and downstream reduction in protein ubiquitination following SA (Cereal) and Myzus persicae (Peach-potato). The fusion basic framework of the PRR-mediated immune system. targets of the Arabidopsis N-end rule pathway. New treatment. RNA-seq analysis demonstrated an almost protein GNA-Hv1a, when orally delivered, is transported Our recent findings based on phosphoproteomics insight into control of storage reserve mobilisation by complete loss of SA-and NPR1-induced immune to the insect’s haemolymph carrying the toxin to the in Arabidopsis and studies of an emerging model the Arg/-N-end rule will be presented. The utility of responsive genes. Taken together, our study shows that site of action, reducing the survival of the insect pests. plant Marchantia polymorpha will be presented. TAILS for proteome annotation, analysis of N-terminal the E3 ligase activities of UPL1, UPL3 and UPL5 play This technology provides a novel target in pest control post-translational modifications and protease profiling central roles in regulating NPR1-dependent immune and is non-harmful to the environment and non-target will also be discussed. responses in plants. organisms. My work determined if the orientation of the toxin to the carrier affected the insecticidal activity of the fusion proteins. This involved expressing the fusion proteins in yeast (Pichia pastoris) as an expression host, purifying the protein, analysing the protein stability and carrying out bioassays on the aforementioned pest species. CELL SECTION SYMPOSIUM POSTER ABSTRACTS 62 CELL SECTION SYMPOSIUM AUTHOR INDEX 63

C S 17.9 7 INVESTIGATING THE AUTHOR INDEX DEGRADATION OF ARABIDOPSIS RIN4 FRAGMENTS AFTER CLEAVAGE BY THE PSEUDOMONAS SYRINGAE EFFECTOR AvrRpt2

MONDAY 11 DECEMBER 2017

KEVIN GOSLIN (MAYNOOTH UNIVERSITY, IRELAND), RÉMI DE MARCHI (MAYNOOTH UNIVERSITY, IRELAND), LENNART ESCHEN- Ahirwar, R N C S 1 7.4 0 Do Choi, Y C S 1 7.3 4 LIPPOLD (LEIBNIZ INSTITUTE OF PLANT BIOCHEMISTRY, GERMANY), SUSANA RIVAS Anggarani, M C S 1 7.3 9 Dong, H C S 1 7.5 8 (LABORATOIRE DES INTERACTIONS PLANTES- MICROORGANISMES (CNRS INRA), FRANCE), Ardeshir, R A CS17.78 Frungillo, L C S 1 7.7 5 JUSTIN LEE (LEIBNIZ INSTITUTE OF PLANT BIOCHEMISTRY, GERMANY), EMMANUELLE GRACIET Asseck, L C S 1 7.7 7 García, S A C S 1 7.4 5 (MAYNOOTH UNIVERSITY, IRELAND) Bachmair, A C S 1 7.8 Gibbs, D J C S 1 7.2 5 [email protected] C S 1 7.3 0 C S 1 7.97 Plants rely on a complex immune system in order to Baerenfaller, K Goslin, K defend themselves against invading pathogens. The C S 1 7.8 8 C S 1 7.2 0 Arabidopsis thaliana protein RPM1-INTERACTING Bailey, M Graciet, E PROTEIN 4 (RIN4) is a negative regulator of plant C S 1 7.5 2 C S 1 7.9 3 immunity that plays a role in both Pathogen- Bender, K W Grey, H Associated Molecular Pattern (PAMP)-triggered C S 1 7.1 9 C S 1 7.3 8 immunity (PTI) and effector-triggered immunity Calderon-Villalobos, L I A Guo, H (ETI). RIN4 is targeted and modified by several C S 1 7.6 9 C S 1 7.74 bacterial effectors, including the Pseudomonas Campanaro, A A C Gwyther, R syringae protease effector AvrRpt2. Cleavage of RIN4 C S 1 7.1 6 CS17.17 by AvrRpt2 results in the generation of three RIN4 Chaplin, A K Hay, R T fragments and resistance protein RPS2-mediated ETI. C S 1 7.4 C S 1 7.1 2 Notably, two of the RIN4 fragments that are released Christie, J Hemsley, P after AvrRpt2 cleavage bear so-called destabilising C S 1 7.3 C S 1 7.8 7 N-terminal residues, which could act as degradation Coaker, G Hõrak, H signals and target the RIN4 fragments for destruction C S 1 7.7 3 C S 1 7.6 8 through the ubiquitin-dependent N-end rule pathway Croley, F Hurst, C H of protein degradation. In addition to RIN4, AvrRpt2 C S 1 7.6 2 C S 1 7.2 8 cleaves several other Arabidopsis proteins from the Davidson, M L H Jones, A NOI-domain-containing protein family. In many C S 1 7.3 2 C S 1 7.5 0 cases, cleavage of these proteins by AvrRpt2 results in De Smet, I Joung, Y H peptides that bear N-terminal destabilising residues. In C S 1 7.8 5 C S 1 7.5 7 this study, we sought to determine if protein fragments DeFalco, T A Kaiserli, E resulting from AvrRpt2 cleavage are degraded through C S 1 7.8 9 C S 1 7.67 the N-end rule pathway. Finding answers to this Derkacheva, M Keyani, R question could be key to our understanding of the CS17.41 C S 1 7.5 6 immune responses that occur downstream cleavage Di Martino, M Kim, D S of RIN4 and related proteins. CELL SECTION SYMPOSIUM AUTHOR INDEX 64 CELL SECTION SYMPOSIUM AUTHOR INDEX 65 AUTHOR INDEX AUTHOR INDEX

Klose, C C S 1 7.6 Millyard, L C S 1 7.8 2 Stampfl, H C S 1 7.9 1

Korbei, B C S 1 7.2 1 Monreal, J A C S 1 7.7 0 Stanovova, M V C S 1 7.8 1

Kwaaitaal, M A C J C S 1 7.1 0 Moody, L A C S 1 7.9 2 Suetsugu, N C S 1 7.6 4

Labandera, A M C S 1 7.6 0 Morrell, B E S C S 1 7.9 4 Sullivan, S C S 1 7.4 6

Labuz, J M C S 1 7.1 1 Nakagami, H C S 1 7.9 5 Tedds, H M C S 1 7.6 6

Lambertucci, S L H C S 1 7.9 0 Niazi, A K C S 1 7.8 4, 86 Theodoulou, F L C S 1 7.9 6

Landymore, J C S 1 7.4 8 Olsen, J V C S 1 7.1 Trujillo, M C S 1 7.2 2

Laurila, M A C S 1 7.7 6 Orosa, B C S 1 7.71 Turnbull, D C S 1 7.4 9

Leftley, N J C S 1 7.7 9 Pavicic, M CS17.61 Uzilday, B C S 1 7.8 0

Lightbourn, L A C S 1 7.4 4, 63 Perrella, G C S 1 7.5 9 Van Breusegem, F CS17.24

Loake, G J C S 1 7.2 3 Pham, J C S 1 7.4 2 Vanhaeren, H C S 1 7.5 3

Lucyshyn, D C S 1 7.1 5, 51 Ravanel, S C S 1 7.1 4 Vert, G C S 1 7.3 1

Luis, I M C S 1 7.4 3 Rudolf, E-E CS17.26 Vissenberg, K C S 1 7.5

Lupanga, U C S 1 7.5 5 Sadanandom, A C S 1 7.7 Vu, L D C S 1 7.3 7

MacNeill, G J C S 1 7.3 3 Serre, N B C B C S 1 7.5 4 Williams, C C S 1 7.6 5

Maria Lois, L C S 1 7.9 Sheikh, A H C S 1 7.3 6 Wirtz, M C S 1 7.1 3

Marques dos Santos, B C S 1 7.8 3 Siddiqui, M A C S 1 7.3 5 Zawawi, D D C S 1 7.7 2

Mata-Perez, C C S 1 7.27 Skelly, M J C S 1 7.47 Zipfel, C C S 1 7.2

Menke, F C S 1 7.2 9 Spoel, S C S 1 7.1 8 SOCIETY FOR EXPERIMENTAL BIOLOGY

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