DOCSLIB.ORG

Gene Regulatory Network for Lateral Root Formation in Arabidopsis Thaliana Duy Chi Trinh

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Gene Regulatory Network for Lateral Root Formation in Arabidopsis Thaliana Duy Chi Trinh Gene regulatory network for lateral root formation in Arabidopsis thaliana Duy Chi Trinh To cite this version: Duy Chi Trinh. Gene regulatory network for lateral root formation in Arabidopsis thaliana. Plants genetics. Université Montpellier, 2019. English. NNT : 2019MONTG003. tel-02304191 HAL Id: tel-02304191 https://tel.archives-ouvertes.fr/tel-02304191 Submitted on 3 Oct 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. THÈSE POUR OBTENIR LE GRADE DE DOCTEUR DE L’UNIVERSITÉ DE MONTPELLIER En Biologie du Développement École doctorale n°584 GAIA : Biodiversité, Agriculture, Alimentation, Environnement, Terre, Eau Unité de recherche DIADE : Diversité, Adaptation et Développement des Plantes Propriétés du réseau de gènes contrôlant l’organisation du primordium de racine latérale chez Arabidopsis thaliana Gene regulatory network for lateral root formation in Arabidopsis thaliana Présentée par TRINH Duy Chi Le 22 mars 2019 Sous la direction de Dr. Laurent LAPLAZE Devant le jury composé de Mr Alain GOJON, Directeur de Recherche, INRA, Montpellier Président du jury Mme Sandra BENSMIHEN, Chargé de Recherche, CNRS, Toulouse Examinateur Mr Frédéric DOMERGUE, Chargé de Recherche, CNRS, Bordeaux Rapporteur Mme Soazig GUYOMARC’H, Maitre de conférences, Université de Montpellier Invité Mr Laurent LAPLAZE, Directeur de Recherche, IRD, Montpellier Directeur de thèse Mme Valérie LEGUÉ, Professeur, Université Blaise Pascal de Clermont-Ferrand Rapporteur Mr Joop VERMEER, Professeur, Université de Zurich Examinateur This PhD was prepared in the DIADE research unit DIversité - Adaptation - DEveloppement des plantes Centre IRD de Montpellier 911 Avenue Agropolis 34394 Montpellier Cedex 5 France 1 Abstract in English Post-embryonic lateral root organogenesis plays an essential role in defining plant root system architecture, and therefore plant growth and fitness. The aim of the thesis is to elucidate the gene regulatory network regulating lateral root development and de novo root meristem formation during root branching in the model plant Arabidopsis thaliana by combining a system- biology-based analysis of lateral root primordium transcriptome dynamics with the functional characterization of genes possibly involved in regulating lateral root organogenesis. The first part of the thesis deals with the identification the target genes of PUCHI, an AP2/EREBP transcription factor that is involved in controlling cell proliferation and differentiation during lateral root formation. We showed that loss of PUCHI function leads to defects lateral root initiation and primordium growth and organisation. We found that several genes coding for proteins of the very long chain fatty acid (VLCFA) biosynthesis machinery are transiently induced in a PUCHI-dependent manner during lateral root development. Moreover, a mutant perturbed in VLCFA biosynthesis (kcs1-5) displays similar lateral root development defects as does puchi-1. In addition, roots of puchi-1 loss of function mutant show enhanced and continuous callus formation in auxin-rich callus induction medium, consistent with the recently reported role of VLCFAs in organizing separated callus proliferation on this inductive growing medium. Thus, our results demonstrate that PUCHI positively regulates the expression of VLCFA biosynthesis genes during lateral root development, and further support the hypothesis that lateral root and callus formation share common genetic regulatory mechanisms. A second part of the thesis specifically addresses the issue of identifying key regulators of root meristem organization in the developing lateral root primordium. Material enabling the tracking of meristem cell identity establishment in developing primordia with live confocal microscopy was generated. A gene network inference was run to predict potential regulatory relationships between genes of interest during the time course of lateral root development. It identified potential regulators of quiescent center formation, a key step in functional organization of the lateral root primordia into a new root apical meristem. The characterization of some of these candidate genes was initiated. Altogether, this work participated in deciphering the genetic regulation of lateral root formation in Arabidopsis thaliana. Key words: gene regulatory network, lateral root, stem cell niche, mersitem formation, very long chain fatty acids (VLCFAs), PUCHI 2 Abstract in French L’organogenèse post-embryonnaire des racines latérales joue un rôle essentiel dans l’établissement de l’architecture du système racinaire des plantes, et donc dans leur croissance et leur performance. L’objectif de cette thèse est de caractériser le réseau de gènes régulant le développement des racines latérales et en particulier, l’organisation fonctionnelle du primordium de racine latérale, formant un nouveau méristème racinaire, chez la plante modèle Arabidopsis thaliana en combinant des études de biologie des systèmes appliquées à la dynamique du transcriptome lors de la formation des racines latérales avec la caractérisation fonctionnelle de gènes candidats pour la régulation de ce phénomène d’organogenèse. La première partie de la thèse concerne l’identification des cibles de PUCHI, un facteur de transcription de type AP2/EREBP impliqué dans le contrôle de la prolifération et de la différentiation cellulaire dans le primordium de racine latérale. Le phénotype liés à la parte de fonction de PUCHI a été caractérisé en détail et à mis en évidence un rôle de ce facteur de transcription dans l'initiation des racines latérales et le développement et l'organisation des primordia. Par l’analyse de profils spatiaux et temporels d’expression de gènes, nous avons pu mettre en évidence que l’expression de gènes codant des protéines impliquées dans la biosynthèse des acides gras à très longues chaînes (VLCFA) est transitoirement activée durant la formation de la racine latérale et que cette dynamique est dépendante de PUCHI. De plus, le mutant kcs1-5, perturbé dans la biosynthèse de VLCFAs, présente un phénotype de développement des racines latérales similaire à celui de puchi-1. Par ailleurs, la perte de fonction puchi-1 augmente fortement la formation de cals continus dans des racines cultivées sur milieu inducteur riche en auxine, ce qui est cohérent avec le rôle récemment décrit des VLCFA racinaires dans la formation et l’organisation de cals distincts lorsque la racine est cultivé sur milieu inducteur de cals. L'ensemble de nos résultats démontre que PUCHI régule positivement l’expression de gènes de biosynthèse de VLCFAs lors de la formation de racines latérales et la callogenèse. Nos résultats confortent également l’hypothèse selon laquelle la formation des racines latérales et celle de cals racinaires partagent des mécanismes de régulation communs. La seconde partie de la thèse s’intéresse à l’identification de facteurs régulateurs clés dans l’organisation fonctionnelle du primordium de racine latérale et particulièrement, l’organisation d’un nouveau méristème racinaire. J’ai contribué à produire de nouvelles lignées de plantes permettant de suivre en temps réel par microscopie confocale la mise en place des identités cellulaires caractéristiques d’un méristème racinaire dans le primordium de racine latérale en développement. En utilisant un algorithme d’inférence de réseau de gènes, j’ai produit puis analysé les relations prédites de régulation entre gènes d’intérêt, afin d’identifier des gènes candidats potentiellement impliqués dans la formation du centre quiescent, un élément clé dans l’organisation du primordium et la mise en place du nouveau méristème racinaire. La caractérisation fonctionnelle de certains de ces gènes candidats a été initiée. Ces travaux de thèse ont donc contribué à mieux comprendre les mécanismes de régulation de la formation des racines latérales chez Arabidopsis thaliana. Mots clés: réseau de régulation du gène, racines latérales, niche de cellules souches, formation de mersitem, acides gras à très longue chaine (VLCFAs), PUCHI 3 ACKNOWLEDGEMENTS First of all, I express my greatest gratitude to my PhD supervisors, Dr. Laurent Laplaze and Dr. Soazig Guyomarc’h. I feel truly privileged to be your student. You two have guided me through this journey with kindness, encouragement and great patience. Thank you very much Dr. Laurent for spending your valuable time discussing via video and answering all my requests with incredible efficiency. Thank you very much Dr. Soazig for finding the time between the university and the lab to be there for enthusiastic discussions, as well as for all the help with my everyday life. I and my little family, especially my daughter, deeply appreciate your generous support during our stay. I thank Dr. Sandra Bensmihen, Dr Frédéric Domergue, Dr. Alain Gojon, Dr. Valérie Legué, and Dr. Joop Vermeer for participating in my PhD defense jury. I am deeply grateful to all members of my PhD committee to my study. Thank you all very much, Dr. Thierry Joet, Dr. Patrick Lemaire, Dr. Philippe Nacry, Dr. François Parcy and Dr. Benjamin
Load more

Recommended publications
  • Mycorrhiza Helper Bacterium Streptomyces Ach 505 Induces
    Research MycorrhizaBlackwell Publishing, Ltd. helper bacterium Streptomyces AcH 505 induces differential gene expression in the ectomycorrhizal fungus Amanita muscaria Silvia D. Schrey, Michael Schellhammer, Margret Ecke, Rüdiger Hampp and Mika T. Tarkka University of Tübingen, Faculty of Biology, Institute of Botany, Physiological Ecology of Plants, Auf der Morgenstelle 1, D-72076 Tübingen, Germany Summary Author for correspondence: • The interaction between the mycorrhiza helper bacteria Streptomyces nov. sp. Mika Tarkka 505 (AcH 505) and Streptomyces annulatus 1003 (AcH 1003) with fly agaric Tel: +40 7071 2976154 (Amanita muscaria) and spruce (Picea abies) was investigated. Fax: +49 7071 295635 • The effects of both bacteria on the mycelial growth of different ectomycorrhizal Email: [email protected] fungi, on ectomycorrhiza formation, and on fungal gene expression in dual culture Received: 3 May 2005 with AcH 505 were determined. Accepted: 16 June 2005 • The fungus specificities of the streptomycetes were similar. Both bacterial species showed the strongest effect on the growth of mycelia at 9 wk of dual culture. The effect of AcH 505 on gene expression of A. muscaria was examined using the suppressive subtractive hybridization approach. The responsive fungal genes included those involved in signalling pathways, metabolism, cell structure, and the cell growth response. • These results suggest that AcH 505 and AcH 1003 enhance mycorrhiza formation mainly as a result of promotion of fungal growth, leading to changes in fungal gene expression. Differential A. muscaria transcript accumulation in dual culture may result from a direct response to bacterial substances. Key words: acetoacyl coenzyme A synthetase, Amanita muscaria, cyclophilin, ectomycorrhiza, mycorrhiza helper bacteria, streptomycetes, suppression subtractive hybridization (SSH).
    [Show full text]
  • Dicot/Monocot Root Anatomy the Figure Shown Below Is a Cross Section of the Herbaceous Dicot Root Ranunculus. the Vascular Tissu
    Dicot/Monocot Root Anatomy The figure shown below is a cross section of the herbaceous dicot root Ranunculus. The vascular tissue is in the very center of the root. The ground tissue surrounding the vascular cylinder is the cortex. An epidermis surrounds the entire root. The central region of vascular tissue is termed the vascular cylinder. Note that the innermost layer of the cortex is stained red. This layer is the endodermis. The endodermis was derived from the ground meristem and is properly part of the cortex. All the tissues inside the endodermis were derived from procambium. Xylem fills the very middle of the vascular cylinder and its boundary is marked by ridges and valleys. The valleys are filled with phloem, and there are as many strands of phloem as there are ridges of the xylem. Note that each phloem strand has one enormous sieve tube member. Outside of this cylinder of xylem and phloem, located immediately below the endodermis, is a region of cells called the pericycle. These cells give rise to lateral roots and are also important in secondary growth. Label the tissue layers in the following figure of the cross section of a mature Ranunculus root below. 1 The figure shown below is that of the monocot Zea mays (corn). Note the differences between this and the dicot root shown above. 2 Note the sclerenchymized endodermis and epidermis. In some monocot roots the hypodermis (exodermis) is also heavily sclerenchymized. There are numerous xylem points rather than the 3-5 (occasionally up to 7) generally found in the dicot root.
    [Show full text]
  • Eudicots Monocots Stems Embryos Roots Leaf Venation Pollen Flowers
    Monocots Eudicots Embryos One cotyledon Two cotyledons Leaf venation Veins Veins usually parallel usually netlike Stems Vascular tissue Vascular tissue scattered usually arranged in ring Roots Root system usually Taproot (main root) fibrous (no main root) usually present Pollen Pollen grain with Pollen grain with one opening three openings Flowers Floral organs usually Floral organs usually in in multiples of three multiples of four or five © 2014 Pearson Education, Inc. 1 Reproductive shoot (flower) Apical bud Node Internode Apical bud Shoot Vegetative shoot system Blade Leaf Petiole Axillary bud Stem Taproot Lateral Root (branch) system roots © 2014 Pearson Education, Inc. 2 © 2014 Pearson Education, Inc. 3 Storage roots Pneumatophores “Strangling” aerial roots © 2014 Pearson Education, Inc. 4 Stolon Rhizome Root Rhizomes Stolons Tubers © 2014 Pearson Education, Inc. 5 Spines Tendrils Storage leaves Stem Reproductive leaves Storage leaves © 2014 Pearson Education, Inc. 6 Dermal tissue Ground tissue Vascular tissue © 2014 Pearson Education, Inc. 7 Parenchyma cells with chloroplasts (in Elodea leaf) 60 µm (LM) © 2014 Pearson Education, Inc. 8 Collenchyma cells (in Helianthus stem) (LM) 5 µm © 2014 Pearson Education, Inc. 9 5 µm Sclereid cells (in pear) (LM) 25 µm Cell wall Fiber cells (cross section from ash tree) (LM) © 2014 Pearson Education, Inc. 10 Vessel Tracheids 100 µm Pits Tracheids and vessels (colorized SEM) Perforation plate Vessel element Vessel elements, with perforated end walls Tracheids © 2014 Pearson Education, Inc. 11 Sieve-tube elements: 3 µm longitudinal view (LM) Sieve plate Sieve-tube element (left) and companion cell: Companion cross section (TEM) cells Sieve-tube elements Plasmodesma Sieve plate 30 µm Nucleus of companion cell 15 µm Sieve-tube elements: longitudinal view Sieve plate with pores (LM) © 2014 Pearson Education, Inc.
    [Show full text]
  • Newly Identified Helper Bacteria Stimulate Ectomycorrhizal Formation
    ORIGINAL RESEARCH ARTICLE published: 24 October 2014 doi: 10.3389/fpls.2014.00579 Newly identified helper bacteria stimulate ectomycorrhizal formation in Populus Jessy L. Labbé*, David J. Weston , Nora Dunkirk , Dale A. Pelletier and Gerald A. Tuskan Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA Edited by: Mycorrhiza helper bacteria (MHB) are known to increase host root colonization by Brigitte Mauch-Mani, Université de mycorrhizal fungi but the molecular mechanisms and potential tripartite interactions are Neuchâtel, Switzerland poorly understood. Through an effort to study Populus microbiome, we isolated 21 Reviewed by: Pseudomonas strains from native Populus deltoides roots. These bacterial isolates were Dale Ronald Walters, Scottish Agricultural College, Scotland characterized and screened for MHB effectiveness on the Populus-Laccaria system. Two Ana Pineda, Wageningen University, additional Pseudomonas strains (i.e., Pf-5 and BBc6R8) from existing collections were Netherlands included for comparative purposes. We analyzed the effect of co-cultivation of these *Correspondence: 23 individual Pseudomonas strains on Laccaria bicolor “S238N” growth rate, mycelial Jessy L. Labbé, Biosciences architecture and transcriptional changes. Nineteen of the 23 Pseudomonas strains tested Division, Oak Ridge National Laboratory, P.O. Box 2008, had positive effects on L. bicolor S238N growth, as well as on mycelial architecture, with MS-6407, Oak Ridge, TN strains GM41 and GM18 having the most significant effect. Four of seven L. bicolor 37831-6407, USA reporter genes, Tra1, Tectonin2, Gcn5, and Cipc1, thought to be regulated during the e-mail: [email protected] interaction with MHB strain BBc6R8, were induced or repressed, while interacting with Pseudomonas strains GM17, GM33, GM41, GM48, Pf-5, and BBc6R8.
    [Show full text]
  • Inhibition of Primary Roots and Stimulation of Lateral Root
    Mol. Cells 29, 251-258, March 31, 2010 DOI/10.1007/s10059-010-0032-0 Molecules and Cells ©2010 KSMCB Inhibition of Primary Roots and Stimulation of Lateral Root Development in Arabidopsis thaliana by the Rhizobacterium Serratia marcescens 90-166 Is through Both Auxin-Dependent and -Independent Signaling Pathways Chun-Lin Shi1,4, Hyo-Bee Park1, Jong Suk Lee1,2, Sangryeol Ryu2, and Choong-Min Ryu1,3,* The rhizobacterium Serratia marcescens strain 90-166 was found in the rhizosphere and rhizoplane, colonize roots and previously reported to promote plant growth and induce stimulate plant growth. As more plant tissues are analyzed for resistance in Arabidopsis thaliana. In this study, the influ- the presence of bacteria, an increasing number of indole acetic ence of strain 90-166 on root development was studied in acid (IAA)-producing PGPR are being detected (Dey et al., vitro. We observed inhibition of primary root elongation, 2004; Rosenblueth and Martinez-Romero, 2006; Unno et al., enhanced lateral root emergence, and early emergence of 2005). Studies of PGPR such as Azospirillum spp. revealed second order lateral roots after inoculation with strain 90- that bacterial IAA biosynthesis contributed to plant root prolif- 166 at a certain distance from the root. Using the DR5::GUS eration (Dobbelaere et al., 1999; Tsavkelova et al., 2007), as transgenic A. thaliana plant and an auxin transport inhibitor, Azospirillum mutants deficient in IAA production did not en- N-1-naphthylphthalamic acid, the altered root development hance root development (Dobbelaere et al., 1999). Increased was still elicited by strain 90-166, indicating that this was not root formation enhances plant mineral uptake and root secre- a result of changes in plant auxin levels.
    [Show full text]
  • Shoot-Derived Cytokinins Systemically Regulate Root Nodulation
    ARTICLE Received 26 Mar 2014 | Accepted 13 Aug 2014 | Published 19 Sep 2014 DOI: 10.1038/ncomms5983 Shoot-derived cytokinins systemically regulate root nodulation Takema Sasaki1,2, Takuya Suzaki1,2, Takashi Soyano1, Mikiko Kojima3, Hitoshi Sakakibara3 & Masayoshi Kawaguchi1,2 Legumes establish symbiotic associations with nitrogen-fixing bacteria (rhizobia) in root nodules to obtain nitrogen. Legumes control nodule number through long-distance communication between roots and shoots, maintaining the proper symbiotic balance. Rhizobial infection triggers the production of mobile CLE-RS1/2 peptides in Lotus japonicus roots; the perception of the signal by receptor kinase HAR1 in shoots presumably induces the production of an unidentified shoot-derived inhibitor (SDI) that translocates to roots and blocks further nodule development. Here we show that, CLE-RS1/2-HAR1 signalling activates the production of shoot-derived cytokinins, which have an SDI-like capacity to systemically suppress nodulation. In addition, we show that LjIPT3 is involved in nodulation-related cytokinin production in shoots. The expression of LjIPT3 is activated in an HAR1-dependent manner. We further demonstrate shoot-to-root long-distance transport of cytokinin in L. japonicus seedlings. These findings add essential components to our understanding of how legumes control nodulation to balance nutritional requirements and energy status. 1 Division of Symbiotic Systems, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan. 2 Department of Basic Biology in the School of Life Science of the Graduate University for Advanced Studies, Nishigonaka 38, Myodaiji, Okazaki 444-8585, Japan. 3 Plant Productivity Systems Research Group, RIKEN Center for Sustainable Resource Science, 1-7-22, Suehiro, Tsurumi, Yokohama 230-0045, Japan.
    [Show full text]
  • The Role of Auxin and Ethylene in Adventitious Root Formation in Arabidopsis and Tomato
    THE ROLE OF AUXIN AND ETHYLENE IN ADVENTITIOUS ROOT FORMATION IN ARABIDOPSIS AND TOMATO BY POORNIMA SUKUMAR A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY In the Department of Biology May 2010 Winston-Salem, North Carolina Approved By: Gloria K. Muday, Ph.D., Advisor Examining Committee: Brenda S. J. Winkel, Ph.D., Chair Susan E. Fahrbach, Ph.D. Anita K. McCauley, Ph.D. Brian W. Tague, Ph.D. ACKNOWLEDGMENTS “Live as if you were to die tomorrow. Learn as if you were to live forever.” Mohandas Gandhi First and foremost, I would like to thank my advisor Dr Gloria Muday for all her help with scientific as well as several aspects of my graduate student life. I appreciate your constant encouragement, support, and advice throughout my graduate studies. I owe my passion for science and teaching to your incessant enthusiasm and challenges. I am grateful to my committee members, Dr Brian Tague, Dr Susan Fahrbach, Dr Anita McCauley, and Dr Brenda Winkel for their encouragement, and assistance. I am indebted to you for providing valuable suggestions and ideas for making this project possible. I appreciate the friendship and technical assistance by all my lab mates. In particular, I like to thank Sangeeta Negi for helping me with tomato research and making the lab more fun. I am grateful to Dan Lewis for his advice and help with figuring out imaging and molecular techniques, and Mary Beth Lovin for her sincere friendship and positive thoughts.
    [Show full text]
  • Application of Ectomycorrhizal Fungi in Vegetative Propagation of Conifers
    Plant Cell, Tissue and Organ Culture 78: 83–91, 2004. 83 © 2004 Kluwer Academic Publishers. Printed in the Netherlands. Review article Application of ectomycorrhizal fungi in vegetative propagation of conifers Karoliina Niemi1,2,∗, Carolyn Scagel3 & Hely Häggman4,5 1Department of Applied Biology, University of Helsinki, P.O. Box 27, FIN-00014 Helsinki, Finland; 2Finnish Forest Research Institute, Parkano Research Station, FIN-39700 Parkano, Finland; 3USDA, Agricultural Re- search Service, Horticultural Crops Research Laboratory, Corvallis, OR 97330, USA; 4Finnish Forest Research Institute, Punkaharju Research Station, FIN-58450 Punkaharju, Finland; 5Department of Biology, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland (∗request for offprints: Fax: +358-9-191 58582; E-mail: Karoliina.Niemi@helsinki.fi) Received 7 February 2003; accepted in revised form 15 October 2003 Key words: acclimatization, adventitious rooting, cutting production, ectomycorrhizas, hypocotyl cuttings, organogenesis, plant growth regulators, somatic embryogenesis Abstract In forestry, vegetative propagation is important for the production of selected genotypes and shortening the se- lection cycles in genetic improvement programs. In vivo cutting production, in vitro organogenesis and somatic embryogenesis are applicable with conifers. However, with most coniferous species these methods are not yet suitable for commercial application. Large-scale production of clonal material using cuttings or organogenesis is hindered by rooting problems and difficulties in the maturation and conversion limit the use of somatic embryo- genesis. Economically important conifers form symbiotic relationship mostly with ectomycorrhizal (ECM) fungi, which increase the fitness of the host tree. Several studies have shown the potential of using ECM fungi in conifer vegetative propagation. Inoculation with specific fungi can enhance root formation and/or subsequent root branch- ing of in vivo cuttings and in vitro adventitious shoots.
    [Show full text]
  • Arabidopsis AZG2, an Auxin Induced Putative Cytokinin Transporter, Regulates Lateral Root Emergence
    bioRxiv preprint doi: https://doi.org/10.1101/2020.01.31.927970; this version posted February 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Title: Arabidopsis AZG2, an auxin induced putative cytokinin transporter, regulates lateral root emergence Tomás M. Tessi1, Sabine Brumm2, Eva Winklbauer2, Benjamin Schumacher2, Carlos I. Lescano1, Claudio A. González3, Dierk Wanke2, Verónica G. Maurino4, Klaus Harter2, Marcelo Desimone1. 1 Instituto Multidisciplinario de Biología Vegetal, CONICET, Av. Vélez Sarsfield 299, 5000 Córdoba, Argentine. 2 Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, 72076 Tübingen, Germany. 3 Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba. Av. Vélez Sarsfield 299, 5000 Córdoba, Argentine. 4 Plant Molecular Physiology and Biotechnology Group, Institute of Developmental and Molecular Biology of Plants, Heinrich Heine University Düsseldorf, Düsseldorf, Germany. Address correspondence to: Marcelo Desimone, E-mail: [email protected] bioRxiv preprint doi: https://doi.org/10.1101/2020.01.31.927970; this version posted February 2, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. ABSTRACT The phytohormones cytokinin (CK) and auxin are key regulators of plant growth and development. During the last decade specialised transport mechanisms turned out to be the key for the control of local and long distance hormone distributions.
    [Show full text]
  • Primary and Secondary Thickening in the Stem of Cordyline Fruticosa (Agavaceae)
    “main” — 2010/8/6 — 20:44 — page 653 — #1 Anais da Academia Brasileira de Ciências (2010) 82(3): 653-662 (Annals of the Brazilian Academy of Sciences) ISSN 0001-3765 www.scielo.br/aabc Primary and secondary thickening in the stem of Cordyline fruticosa (Agavaceae) MARINA B. CATTAI and NANUZA L. DE MENEZES Instituto de Biociências, Universidade de São Paulo Rua do Matão, 277, Cidade Universitária, Butantã, 05508-090 São Paulo, SP, Brasil Manuscript received on March 4, 2010; accepted for publication on May 5, 2010 ABSTRACT The growth in thickness of monocotyledon stems can be either primary, or primary and secondary. Most of the authors consider this thickening as a result of the PTM (Primary Thickening Meristem) and the STM (Secondary Thickening Meristem) activity. There are differences in the interpretation of which meristem would be responsible for primary thickening. In Cordyline fruticosa the procambium forms two types of vascular bundles: collateral leaf traces (with proto and metaxylem and proto and metaphloem), and concentric cauline bundles (with metaxylem and metaphloem). The procambium also forms the pericycle, the outermost layer of the vascular cylinder consisting of smaller and less intensely colored cells that are divided irregularly to form new vascular bundles. The pericycle continues the procambial activity, but only produces concentric cauline bundles. It was possible to conclude that the pericycle is responsible for the primary thickening of this species. Further away from the apex, the pericyclic cells undergo periclinal divisions and produce a meristematic layer: the secondary thickening meristem. The analysis of serial sections shows that the pericycle and STM are continuous in this species, and it is clear that the STM originates in the pericycle.
    [Show full text]
  • Mechanical Induction of Lateral Root Initiation in Arabidopsis Thaliana
    The Pennsylvania State University The Graduate School The Huck Institutes of the Life Sciences MECHANICAL INDUCTION OF LATERAL ROOT INITIATION A Dissertation in Integrative Biosciences by Gregory L. Richter ©2009 Gregory L. Richter Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy May 2009 ii The dissertation of Gregory L. Richter was reviewed and approved* by the following: Richard Cyr Professor of Biology Dissertation Advisor and Chair of Committee Simon Gilroy Professor of Botany David Braun Assistant Professor of Biology Randen Patterson Assistant Professor of Biology Timothy McNellis Associate Professor of Plant Pathology Peter Hudson Willaman Professor of Biology Director, Huck Institutes of the Life Sciences *Signatures are on file in the Graduate School iii ABSTRACT Unlike mammals whose development is limited to a short temporal window, plants produce organs de novo throughout their lifetime in order to adapt their architecture to the prevailing environmental conditions. Development of the root system represents a morphogenetic program where the positioning of new lateral organs occurs through the periodic recruitment of pericycle cells to become founder cells of a new lateral root (LR) primordium. While the hormone auxin appears intimately involved in specifying LR formation, it remains unclear why some pericycle cells are specified to initiate a LR while others are not. In the following thesis, I show that mechanical forces can act as one of the triggers for founder cell formation and so entrain the pattern of LR production to the environment. I observed that transient physical bending of the root was capable of eliciting LR formation to the convex side of the curve.
    [Show full text]
  • Endofungal Bacteria Increase Fitness of Their Host Fungi and Impact Their Association with Crop Plants
    Impact of endofungal bacteria in fungus-plant interactions Alabid et al. Curr. Issues Mol. Biol. (2019) 30: 59-74. caister.com/cimb Endofungal Bacteria Increase Fitness of their Host Fungi and Impact their Association with Crop Plants Ibrahim Alabid1, Stefanie P. Glaeser2 and Karl- their role in supporting sustainable agriculture by Heinz Kogel1* promoting plant growth, improving plant resistance, and decreasing yield loss caused by many microbial 1Institute of Phytopathology, IFZ Research Centre pathogens. for Biosystems, Land Use and Nutrition, Justus Liebig University, D-35392 Giessen, Germany Endobacteria in plant-colonizing fungi 2Institute of Applied Microbiology, IFZ Research Endofungal bacteria inhabit the cytoplasm of fungal Centre for Biosystems, Land Use and Nutrition, cells (Figure 1). They commonly establish beneficial Justus Liebig University, D-35392 Giessen, relationships (positive symbioses) with their plant- Germany colonizing host fungi thereby forming tripartite interactions that comprise the bacterium, the fungus *[email protected] and the plant (Perotto and Bonfante, 1997; Bonfante and Anca, 2009; Desirò et al., 2014; Moebius et al., DOI: https://dx.doi.org/10.21775/cimb.030.059 2014; Erlacher et al., 2015; Glaeser et al., 2016; Salvioli et al., 2016). From the historical perspective, Abstract: Mosse (1970) was the first to describe intracellular Endofungal bacteria are bacterial symbionts of fungi structures very similar to bacteria, called Bacteria- that exist within fungal hyphae and spores. There is Like Organisms (BLOs) inside fungal hyphae increasing evidence that these bacteria, alone or in (Figure 2). Since then, BLOs and bacteria were combination with their fungal hosts play a critical detected in glomeromycotan arbuscular mycorrhiza role in tripartite symbioses with plants, where they may contribute to plant growth and disease resistance to microbial pathogens.
    [Show full text]