DOCSLIB.ORG

Streptomyces Scabies and Identification Of

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Streptomyces Scabies and Identification Of Coronafacoyl phytotoxin biosynthesis in Streptomyces scabies and identification of common scab-associated Streptomyces species in Newfoundland By © Luke Bown A thesis submitted to the School of Graduate Studies in partial fulfillment for the requirements for the degree of Doctor of Philosophy Department of Biology Memorial University of Newfoundland September 2018 St. John’s, Newfoundland and Labrador Abstract The Streptomyces are a genus of Gram-positive Actinomycete bacteria that are best known for their ability to produce a wide variety of secondary metabolite compounds (also known as specialized metabolites). Many of these compounds can allow the Streptomyces to interact with other organisms in a symbiotic manner, while other compounds such as antibiotics can have a deleterious effect on organisms that interact with them. A subset of Streptomyces species are pathogenic to plants and have been shown to use secondary metabolites as virulence factors for host colonization and infection. For example, Streptomyces scabies (syn. S. scabiei) is a well-characterized plant pathogen that causes the economically important disease potato common scab, and it produces several secondary metabolites that are known or suspected to contribute to the infection process. One such metabolite is coronafacoyl-L-isoleucine (CFA-Ile), which is a member of the coronafacoyl family of phytotoxins that contribute to the virulence phenotype of several different plant pathogenic bacteria. The best characterized coronafacoyl phytotoxin is coronatine (COR), which is produced by Pseudomonas syringae. The biosynthesis of COR and CFA-Ile involves a gene cluster that is highly conserved in both P. syringae and S. scabies, suggesting that the biosynthetic pathway for producing these metabolites is similar in both organisms. However, there is also evidence that some differences exist in the pathways leading to coronafacoyl phytotoxin production in P. syringae and S. scabies. The first objective of this study was to further elucidate the biosynthetic pathway for producing CFA-Ile in S. scabies by studying the role of three genes, oxr, sdr and CYP107AK1, in the production of this metabolite. This study examined the mechanism of action of the Cfl ii enzyme, which is conserved in both P. syringae and S. scabies and is thought to catalyze the final step in coronafacoyl phytotoxin biosynthesis. The final objective of this study was to investigate the Streptomyces species associated with potato common scab in Newfoundland and to characterize the virulence factors that are produced by these species. The results of this study indicate that the Sdr and CYP107AK1 enzymes are utilized in the introduction of the keto group on the bicyclic hydrindane ring of the CFA polyketide. CYP107AK1 is believed to introduce a hydroxyl group onto the CFA polyketide, which is subsequently oxidized by the Sdr enzyme to form the keto group. Lack of experimental evidence prevented the determination of function for the Oxr enzyme, although it is predicted to be involved in the formation of a C-C double bond in the CFA polyketide based on homology to other F420-dependant oxidoreductase genes. The Cfl enzyme was shown to function through a process of adenylation in the ligation of CFA to an amino acid of L-isoleucine. These findings indicate that S. scabies utilizes a unique biosynthetic pathway for the biosynthesis of CFA in comparison to P. syringae. Observation of Streptomyces species associated with potato scab in Newfoundland displayed a prevalence of S. europaeiscabiei and an absence of S. scabies in the identified samples. This may indicate that S. europaeiscabiei is the predominant scab-associated pathogen on the island of Newfoundland. iii Acknowledgements I would like to thank my supervisor Dr. Dawn Bignell for accepting me into her lab, for all the help that she has given me and for everything that she has taught me over the past four years. I would also like to thank my supervisory committee members, Dr. Kapil Tahlan and Dr. Martin Mulligan, for the feedback and help that they have provided me during this project. I want to thank Dr. Celine Schneider, Linda Windsor and Dr. Stefani Egli from CCART for their help with the structural analysis portion of this work. I would also like to thank the former and current members of the Bignell lab who have contributed to this work, Dr. Joanna Fyans, Mead Altowairish, Phoebe Li and especially Lancy Cheng, who provided me with an immense amount of help with all parts of this project and especially with the protein analysis. I also want to thank Brandon Piercey from the Tahlan lab who helped me with the statistical analysis used in the enzyme function portion of this study. iv Table of Contents Abstract……………………………………………………...…………………………….ii Acknowledgements…………………………...…………………….…………………….iv Table of Contents………………………………………………………………………….v List of Figures…………………………………………………………………...……….xiv List of Tables……………………………………………………………………..............xx List of Symbols, Abbreviations and Nomenclature……………………………………...xxi Chapter 1: Introduction and Overview………………………………………………….…1 1.1 Background ………………………………………………………………..…..1 1.2 Lifestyle and Reproduction………………………………….……….………...1 1.3 Secondary Metabolite Production…………………………………….………..3 1.4 Pathogenic Streptomyces………………………………………………………7 1.5 Virulence Factors…………………………………………………….………...9 1.5.1 Nec1…………………………………………………………….…..10 1.5.2 TomA…………………………………………………………….…11 1.5.3 Thaxtomin A………………………………………………………..12 1.6 Coronafacoyl Phytotoxins…………………………………………….………13 1.7 Coronafacoyl Phytotoxin Biosynthesis……………………………….………19 v 1.8 Thesis Objectives……………………………………………………….……23 1.9 References……………………………………………………………………26 1.10 Figures………………………………………………………………………43 Statement of Co-Authorship……………………………………………………………...53 Chapter 2: Production of the Streptomyces scabies coronafacoyl phytotoxins involves a novel biosynthetic pathway with an F420-dependent oxidoreductase and a short-chain dehydrogenase/reductase…………………………………………………………………57 2.1 Abstract...……………………………………………………………………..58 2.2 Introduction…………………………………………………………………..58 2.3 Results ……………………………………………………………………….62 2.3.1 Bioinformatics analyses indicate that oxr and sdr encode a predicted F420-dependent oxidoreductase and a short chain dehydrogenase/reductase, respectively……………………………………………………………….62 2.3.2 Deletion of oxr and sdr leads to a significant reduction in CFA-Ile production in S. scabies…………………………………………………..63 2.3.3 Structural elucidation of the accumulated metabolites in the sdr mutant indicates a role for Sdr in coronafacic acid biosynthesis………….65 2.3.4 The accumulated metabolites in the sdr mutant exhibit varying degrees of potato tuber tissue hypertrophy - inducing activity……………67 vi 2.4 Discussion…………………………………………………………………….68 2.5 Experimental Procedures …………………………………………………….73 2.5.1 Bacterial strains, growth conditions and maintenance………………73 2.5.2 Plasmids, cosmids, primers and DNA manipulations……………….74 2.5.3 Construction of the S. scabies oxr and sdr gene deletion mutants..75 2.5.4 Complementation of the oxr and sdr deletion mutants…………..76 2.5.5 Analysis of N-coronafacoyl phytotoxin production………………...76 2.5.6 Potato tuber slice bioassay………………………………………….77 2.5.7 Purification of N-coronafacoyl compounds………………………...77 2.5.8 Structural elucidation of N-coronafacoyl compounds from S. scabies…………………………………………………………………78 2.5.9 Bioinformatics analyses…………………………………….………79 2.6 Acknowledgements……………………………………………..……………79 2.7 References……………………………………………………………………80 2.8 Figures and Tables……………………………………………………………87 2.7 Supplementary Materials……………………………………………………101 Chapter 3: Biosynthesis and evolution of coronafacoyl phytotoxin production in the common scab pathogen Streptomyces scabies…………………………………………..119 3.1 Abstract……………………………………………………………………...120 vii 3.2 Introduction…………………………………………………………………121 3.3 Results………………………………………………………………………124 3.3.1 CYP107AK1 encodes a predicted cytochrome P450 monooxygenase…………………………………………………………124 3.3.2 Gene deletion analysis confirms that CYP107AK1 plays a direct role in CFA biosynthesis in S. scabies………………………………………125 3.3.3 The attached oxygen at position C-2 is important for the bioactivity of CFA-Ile…………………………………………………………….……127 3.3.4 The CYP107AK1 gene is conserved in a subset of bacterial CFA biosynthetic gene clusters……………………………………………….127 3.3.5 Gene content and phylogenetic analyses provide insights into the evolution of coronafacoyl phytotoxin biosynthesis in bacteria…………129 3.4 Discussion…………………………………………………………………...132 3.5 Experimental Procedures……………………………………………………137 3.5.1 Bacterial strains and culture conditions……………………………137 3.5.2 Construction of the S. scabies ∆CYP107AK1 gene deletion mutant…………………………………………………………………...138 3.5.3 Analysis of N-coronafacoyl phytotoxin production………………139 viii 3.5.4 Purification of N-coronafacoyl biosynthetic intermediates……….139 3.5.5 Structural elucidation of the N-coronafacoyl biosynthetic intermediates…………………………………………………………....139 3.5.6 Potato tuber slice bioassay…………………………………………140 3.5.7 Bioinformatics analyses…………………………………………...141 3.6 Acknowledgements…………………………………………………………142 3.7 References…………………………………………………………………..142 3.8 Figures and Tables…………………………………………………………..150 3.9 Supplementary Information………………………………………………....161 Chapter 4: Purification of N-Coronafacoyl phytotoxins from Streptomyces scabies…...167 4.1 Abstract……………………………………………………………………...167 4.2 Introduction…………………………………………………………………167 4.3 Materials and Reagents……………………………………………………...169 4.4 Equipment…………………………………………………………………...171
Load more

Recommended publications
  • Poisonous Plants of the Southern United States
    Poisonous Plants of the Southern United States Poisonous Plants of the Southern United States Common Name Genus and Species Page atamasco lily Zephyranthes atamasco 21 bitter sneezeweed Helenium amarum 20 black cherry Prunus serotina 6 black locust Robinia pseudoacacia 14 black nightshade Solanum nigrum 16 bladderpod Glottidium vesicarium 11 bracken fern Pteridium aquilinum 5 buttercup Ranunculus abortivus 9 castor bean Ricinus communis 17 cherry laurel Prunus caroliniana 6 chinaberry Melia azederach 14 choke cherry Prunus virginiana 6 coffee senna Cassia occidentalis 12 common buttonbush Cephalanthus occidentalis 25 common cocklebur Xanthium pensylvanicum 15 common sneezeweed Helenium autumnale 19 common yarrow Achillea millefolium 23 eastern baccharis Baccharis halimifolia 18 fetterbush Leucothoe axillaris 24 fetterbush Leucothoe racemosa 24 fetterbush Leucothoe recurva 24 great laurel Rhododendron maxima 9 hairy vetch Vicia villosa 27 hemp dogbane Apocynum cannabinum 23 horsenettle Solanum carolinense 15 jimsonweed Datura stramonium 8 johnsongrass Sorghum halepense 7 lantana Lantana camara 10 maleberry Lyonia ligustrina 24 Mexican pricklepoppy Argemone mexicana 27 milkweed Asclepias tuberosa 22 mountain laurel Kalmia latifolia 6 mustard Brassica sp . 25 oleander Nerium oleander 10 perilla mint Perilla frutescens 28 poison hemlock Conium maculatum 17 poison ivy Rhus radicans 20 poison oak Rhus toxicodendron 20 poison sumac Rhus vernix 21 pokeberry Phytolacca americana 8 rattlebox Daubentonia punicea 11 red buckeye Aesculus pavia 16 redroot pigweed Amaranthus retroflexus 18 rosebay Rhododendron calawbiense 9 sesbania Sesbania exaltata 12 scotch broom Cytisus scoparius 13 sheep laurel Kalmia angustifolia 6 showy crotalaria Crotalaria spectabilis 5 sicklepod Cassia obtusifolia 12 spotted water hemlock Cicuta maculata 17 St. John's wort Hypericum perforatum 26 stagger grass Amianthum muscaetoxicum 22 sweet clover Melilotus sp .
    [Show full text]
  • Classical Biological Control of Arthropods in Australia
    Classical Biological Contents Control of Arthropods Arthropod index in Australia General index List of targets D.F. Waterhouse D.P.A. Sands CSIRo Entomology Australian Centre for International Agricultural Research Canberra 2001 Back Forward Contents Arthropod index General index List of targets The Australian Centre for International Agricultural Research (ACIAR) was established in June 1982 by an Act of the Australian Parliament. Its primary mandate is to help identify agricultural problems in developing countries and to commission collaborative research between Australian and developing country researchers in fields where Australia has special competence. Where trade names are used this constitutes neither endorsement of nor discrimination against any product by the Centre. ACIAR MONOGRAPH SERIES This peer-reviewed series contains the results of original research supported by ACIAR, or material deemed relevant to ACIAR’s research objectives. The series is distributed internationally, with an emphasis on the Third World. © Australian Centre for International Agricultural Research, GPO Box 1571, Canberra ACT 2601, Australia Waterhouse, D.F. and Sands, D.P.A. 2001. Classical biological control of arthropods in Australia. ACIAR Monograph No. 77, 560 pages. ISBN 0 642 45709 3 (print) ISBN 0 642 45710 7 (electronic) Published in association with CSIRO Entomology (Canberra) and CSIRO Publishing (Melbourne) Scientific editing by Dr Mary Webb, Arawang Editorial, Canberra Design and typesetting by ClarusDesign, Canberra Printed by Brown Prior Anderson, Melbourne Cover: An ichneumonid parasitoid Megarhyssa nortoni ovipositing on a larva of sirex wood wasp, Sirex noctilio. Back Forward Contents Arthropod index General index Foreword List of targets WHEN THE CSIR Division of Economic Entomology, now Commonwealth Scientific and Industrial Research Organisation (CSIRO) Entomology, was established in 1928, classical biological control was given as one of its core activities.
    [Show full text]
  • Kaistella Soli Sp. Nov., Isolated from Oil-Contaminated Soil
    A001 Kaistella soli sp. nov., Isolated from Oil-contaminated Soil Dhiraj Kumar Chaudhary1, Ram Hari Dahal2, Dong-Uk Kim3, and Yongseok Hong1* 1Department of Environmental Engineering, Korea University Sejong Campus, 2Department of Microbiology, School of Medicine, Kyungpook National University, 3Department of Biological Science, College of Science and Engineering, Sangji University A light yellow-colored, rod-shaped bacterial strain DKR-2T was isolated from oil-contaminated experimental soil. The strain was Gram-stain-negative, catalase and oxidase positive, and grew at temperature 10–35°C, at pH 6.0– 9.0, and at 0–1.5% (w/v) NaCl concentration. The phylogenetic analysis and 16S rRNA gene sequence analysis suggested that the strain DKR-2T was affiliated to the genus Kaistella, with the closest species being Kaistella haifensis H38T (97.6% sequence similarity). The chemotaxonomic profiles revealed the presence of phosphatidylethanolamine as the principal polar lipids;iso-C15:0, antiso-C15:0, and summed feature 9 (iso-C17:1 9c and/or C16:0 10-methyl) as the main fatty acids; and menaquinone-6 as a major menaquinone. The DNA G + C content was 39.5%. In addition, the average nucleotide identity (ANIu) and in silico DNA–DNA hybridization (dDDH) relatedness values between strain DKR-2T and phylogenically closest members were below the threshold values for species delineation. The polyphasic taxonomic features illustrated in this study clearly implied that strain DKR-2T represents a novel species in the genus Kaistella, for which the name Kaistella soli sp. nov. is proposed with the type strain DKR-2T (= KACC 22070T = NBRC 114725T). [This study was supported by Creative Challenge Research Foundation Support Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF- 2020R1I1A1A01071920).] A002 Chitinibacter bivalviorum sp.
    [Show full text]
  • Alloactinosynnema Sp
    University of New Mexico UNM Digital Repository Chemistry ETDs Electronic Theses and Dissertations Summer 7-11-2017 AN INTEGRATED BIOINFORMATIC/ EXPERIMENTAL APPROACH FOR DISCOVERING NOVEL TYPE II POLYKETIDES ENCODED IN ACTINOBACTERIAL GENOMES Wubin Gao University of New Mexico Follow this and additional works at: https://digitalrepository.unm.edu/chem_etds Part of the Bioinformatics Commons, Chemistry Commons, and the Other Microbiology Commons Recommended Citation Gao, Wubin. "AN INTEGRATED BIOINFORMATIC/EXPERIMENTAL APPROACH FOR DISCOVERING NOVEL TYPE II POLYKETIDES ENCODED IN ACTINOBACTERIAL GENOMES." (2017). https://digitalrepository.unm.edu/chem_etds/73 This Dissertation is brought to you for free and open access by the Electronic Theses and Dissertations at UNM Digital Repository. It has been accepted for inclusion in Chemistry ETDs by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. Wubin Gao Candidate Chemistry and Chemical Biology Department This dissertation is approved, and it is acceptable in quality and form for publication: Approved by the Dissertation Committee: Jeremy S. Edwards, Chairperson Charles E. Melançon III, Advisor Lina Cui Changjian (Jim) Feng i AN INTEGRATED BIOINFORMATIC/EXPERIMENTAL APPROACH FOR DISCOVERING NOVEL TYPE II POLYKETIDES ENCODED IN ACTINOBACTERIAL GENOMES by WUBIN GAO B.S., Bioengineering, China University of Mining and Technology, Beijing, 2012 DISSERTATION Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Chemistry The University of New Mexico Albuquerque, New Mexico July 2017 ii DEDICATION This dissertation is dedicated to my altruistic parents, Wannian Gao and Saifeng Li, who never stopped encouraging me to learn more and always supported my decisions on study and life.
    [Show full text]
  • Genomic and Phylogenomic Insights Into the Family Streptomycetaceae Lead to Proposal of Charcoactinosporaceae Fam. Nov. and 8 No
    bioRxiv preprint doi: https://doi.org/10.1101/2020.07.08.193797; this version posted July 8, 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. 1 Genomic and phylogenomic insights into the family Streptomycetaceae 2 lead to proposal of Charcoactinosporaceae fam. nov. and 8 novel genera 3 with emended descriptions of Streptomyces calvus 4 Munusamy Madhaiyan1, †, * Venkatakrishnan Sivaraj Saravanan2, † Wah-Seng See-Too3, † 5 1Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 6 Singapore 117604; 2Department of Microbiology, Indira Gandhi College of Arts and Science, 7 Kathirkamam 605009, Pondicherry, India; 3Division of Genetics and Molecular Biology, 8 Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, 9 Malaysia 10 *Corresponding author: Temasek Life Sciences Laboratory, 1 Research Link, National 11 University of Singapore, Singapore 117604; E-mail: [email protected] 12 †All these authors have contributed equally to this work 13 Abstract 14 Streptomycetaceae is one of the oldest families within phylum Actinobacteria and it is large and 15 diverse in terms of number of described taxa. The members of the family are known for their 16 ability to produce medically important secondary metabolites and antibiotics. In this study, 17 strains showing low 16S rRNA gene similarity (<97.3 %) with other members of 18 Streptomycetaceae were identified and subjected to phylogenomic analysis using 33 orthologous 19 gene clusters (OGC) for accurate taxonomic reassignment resulted in identification of eight 20 distinct and deeply branching clades, further average amino acid identity (AAI) analysis showed 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.07.08.193797; this version posted July 8, 2020.
    [Show full text]
  • Mould Growth on Building Materials Secondary Matabolites, Mycoxocins and Biomarkers
    Downloaded from orbit.dtu.dk on: Oct 05, 2021 Mould growth on building materials Secondary matabolites, mycoxocins and biomarkers Nielsen, Kristian Fog Publication date: 2001 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Nielsen, K. F. (2001). Mould growth on building materials: Secondary matabolites, mycoxocins and biomarkers. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Mould growth on building materials Secondary metabolites, mycotoxins and biomarkers Kristian Fog Nielsen The Mycology Group Biocentrum-DTU Technical University of Denmark Lyngby 2002 Mould growth on building materials Secondary metabolites, mycotoxins and biomarkers ISBN 87-88584-65-8 © Kristian Fog Nielsen [email protected] Phone + 45 4525 2600 Fax. + 45 4588 4922. The Mycology Group, Biocentrum-DTU Technical University of Denmark, Building 221 Søltofts Plads, Building 221, DK-2800 Kgs. Lyngby, Denmark Energy and Indoor Climate Division Danish Building Research Institute Dr.
    [Show full text]
  • Antimicrobial Activity of Actinomycetes and Characterization of Actinomycin-Producing Strain KRG-1 Isolated from Karoo, South Africa
    Brazilian Journal of Pharmaceutical Sciences Article http://dx.doi.org/10.1590/s2175-97902019000217249 Antimicrobial activity of actinomycetes and characterization of actinomycin-producing strain KRG-1 isolated from Karoo, South Africa Ivana Charousová 1,2*, Juraj Medo2, Lukáš Hleba2, Miroslava Císarová3, Soňa Javoreková2 1 Apha medical s.r.o., Clinical Microbiology Laboratory, Slovak Republic, 2 Slovak University of Agriculture in Nitra, Faculty of Biotechnology and Food Sciences, Department of Microbiology, Slovak Republic, 3 University of SS. Cyril and Methodius in Trnava, Faculty of Natural Sciences, Department of Biology, Slovak Republic In the present study we reported the antimicrobial activity of actinomycetes isolated from aridic soil sample collected in Karoo, South Africa. Eighty-six actinomycete strains were isolated and purified, out of them thirty-four morphologically different strains were tested for antimicrobial activity. Among 35 isolates, 10 (28.57%) showed both antibacterial and antifungal activity. The ethyl acetate extract of strain KRG-1 showed the strongest antimicrobial activity and therefore was selected for further investigation. The almost complete nucleotide sequence of the 16S rRNA gene as well as distinctive matrix-assisted laser desorption/ionization-time-of-flight/mass spectrometry (MALDI-TOF/MS) profile of whole-cell proteins acquired for strain KRG-1 led to the identification ofStreptomyces antibioticus KRG-1 (GenBank accession number: KX827270). The ethyl acetate extract of KRG-1 was fractionated by HPLC method against the most suppressed bacterium Staphylococcus aureus (Newman). LC//MS analysis led to the identification of the active peak that exhibited UV-VIS maxima at 442 nm and the ESI-HRMS spectrum + + showing the prominent ion clusters for [M-H2O+H] at m/z 635.3109 and for [M+Na] at m/z 1269.6148.
    [Show full text]
  • Poisonous Plant Guide Reprinted from the Merck Veterinary Manual, 8Th Ed., 1998, with Permission of the Publisher, Merck & Co., Inc.,Whitehouse Station, N.J
    Poisonous Plant Guide Reprinted from The Merck Veterinary Manual, 8th ed., 1998, with permission of the publisher, Merck & Co., Inc.,Whitehouse Station, N.J. This chart may be used as a guide to preventing pet exposure to poisonous plants. Call your veterinarian immediately if you suspect your pet has been exposed to any poisonous substance. Agave Brunfelsia Americana (Agavaceae): Caladium pauciflora var spp (Araceae): Century Plant, Aloe Barbadensis (vera) (Liliaceae): floribunda (Solanaceae): Caladium, Fancy leaf American aloe Barbados aloe, Curacao aloe Yesterday-today-and-tomorrow, caladium, Angel wings Lady-of-the-night CHARACTERISTICS: Clumps of thick, CHARACTERISTICS: Succulent herb with cluster of Aglaonema CHARACTERISTICS: Perennial herbs with long-shaped blue/green leaves with hook narrow fleshy, spinous or coarsely serrated margin CHARACTERISTICS: Evergreen shrubs to small trees with (margin) and pointed spines (tip). Central modestum simple, heart-shaped thin, highlighted veins, leaves, with hook spines on leaf margin. Dense alternate, undivided, toothless, thick rather leathery flower stalk with small tubular (Araceae): variegated leaves; yellow green spathe; grown spiked tubular yellow flowers at end of single stalk. lustrous leaves.Winter-blooming; large showy flowers in clusters. Chinese evergreen, from rhizomes. Painted drop tongue sometimes fragrant flowers, clustered or solitary TOXIC PRINCIPLES AND EFFECTS: Contains anthraquinone at the branch ends, with 5-lobed tubular calyx, TOXIC PRINCIPLES AND EFFECTS: Calcium oxalate TOXIC PRINCIPLES AND EFFECTS: Sap contains glycosides (barbaloin, emodin) and chrysophanic CHARACTERISTICS: Central stem with solid 5 petals, and funnel-shaped corolla. crystals and unknowns found in all parts, especially calcium oxalate crystals; saponins and acid in the latex of the leaves; higher medium green or splotched gray/green Fruits berry-like capsules.
    [Show full text]
  • Community Ecology and Sirex Noctilio: Interactions with Microbial Symbionts and Native Insects
    ABSTRACT Title of Document: Community Ecology and Sirex noctilio: Interactions with Microbial Symbionts and Native Insects Brian Matthew Thompson, Doctor of Philosophy, 2013 Directed By: Assistant Professor, Daniel S. Gruner, Department of Entomology Sirex noctilio is an invasive woodwasp with a global distribution that feeds on the sapwood of pine trees. Wood-feeding in the basal Hymenoptera (sawflies) arose out of sequential adaptations to feeding on nutrient poor and digestively refractive internal plant organs (xylem). Symbiotic association with White-rot fungi are thought to aid overcoming nutritional and digestive barriers, including exceedingly low nitrogen (N) and refractory lignocellulosic polymers. In this dissertation I evaluate wood-feeding relative to nutrition, symbiosis and biotic resistance to invasion of exotic North American habitats in Sirex noctilio [Hymenoptera: Siricidae]. I evaluated nutrient relations within fungal mutualism using: 1) functional morphological analysis of insect feeding, 2) sterol molecules to determine diet sources and 3) metagenomic and isotopic analyses for discovery of novel microbial associates and their associated nutrient pathways. Nutritional constraints of wood feeding are potentially compounded by the presence of diverse fungal and insect communities as they divide the tree resource. I examined the role biotic resistance to Sirex and its fungal mutualist, Amylostereum, in North America using field and laboratory experiments. Morphological evidence supported a role for Amylostereum in external digestion of wood. Observational evidence confirmed Sirex larvae did not ingest wood biomass but preferentially extracted liquid substances via specialized structures of mandibles. Sterol analysis indicated plant compounds as the primary constituent of the diet, while metagenomic analysis of bacteria and their metabolic pathways showed a bacterial microbiome adapted to short chain plant polymers, starch and sugar metabolism.
    [Show full text]
  • Proving the Mode of Action of Phytotoxic Phytochemicals
    plants Review Proving the Mode of Action of Phytotoxic Phytochemicals Stephen O. Duke 1,* , Zhiqiang Pan 2 and Joanna Bajsa-Hirschel 2 1 National Center for Natural Products Research, School of Pharmacy, University of Mississippi, Oxford, MS 38655, USA 2 Natural Products Utilization Research Unit, Agricultural Research Service, United States Department of Agriculture, Oxford, MS 38655, USA; [email protected] (Z.P.); [email protected] (J.B.-H.) * Correspondence: [email protected]; Tel.: +1-662-915-7882 Received: 20 November 2020; Accepted: 7 December 2020; Published: 11 December 2020 Abstract: Knowledge of the mode of action of an allelochemical can be valuable for several reasons, such as proving and elucidating the role of the compound in nature and evaluating its potential utility as a pesticide. However, discovery of the molecular target site of a natural phytotoxin can be challenging. Because of this, we know little about the molecular targets of relatively few allelochemicals. It is much simpler to describe the secondary effects of these compounds, and, as a result, there is much information about these effects, which usually tell us little about the mode of action. This review describes the many approaches to molecular target site discovery, with an attempt to point out the pitfalls of each approach. Clues from molecular structure, phenotypic effects, physiological effects, omics studies, genetic approaches, and use of artificial intelligence are discussed. All these approaches can be confounded if the phytotoxin has more than one molecular target at similar concentrations or is a prophytotoxin, requiring structural alteration to create an active compound.
    [Show full text]
  • The Emergence of Grass Root Chemical Ecology
    COMMENTARY The emergence of grass root chemical ecology Stephen O. Duke* Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture, P.O. Box 8048, University, MS 38677 llelopathy is defined by most isoxazolin-5-on-2yl)-alanine, which inhib- converted to L-DOPA, a known phyto- scientists as the adverse effect its root growth on nonlegume plant toxin. Bertin et al. state that this is un- of one plant species on another species (12), although this nonprotein likely because L-DOPA is significantly through production of phyto- amino acid is much less phytotoxic than less phytotoxic than m-tyrosine. How- Atoxins (allelochemicals), although more m-tyrosine. ever, m-tyrosine might be taken up expansive definitions have been formu- Finding that m-tyrosine is a potent more readily by plant cells than lated. Allelopathy is but one component phytotoxin leads to many interesting L-DOPA, leaving conversion to L-DOPA of plant/plant interference, the other questions deserving further inquiry. as a potentially more limiting step. Can being competition for resources such as First, how does the producing species m-tyrosine be converted to L-DOPA by nutrients, light, and water. Allelopathy protect itself from autotoxicity? It seems a cell-free extract of a species suscepti- has been a recognized phenomenon for that m-tyrosine is broadly phytotoxic ble to m-tyrosine? If so, is the process many years (1), but prominent ecologists with some differences in plant species highly efficient in vivo? Synthetic pro- have argued that allelopathy is seldom susceptibility, so what mechanism does herbicides that are inactive at the molec- a significant component of interference the producing plant use to avoid the ular target site are much more effective (e.g., ref.
    [Show full text]
  • Interactions Between the Woodwasp Sirex Noctilio and Co-Habiting Phloem- and Woodboring Beetles, and Their Fungal Associates in Southern Ontario
    Interactions between the Woodwasp Sirex noctilio and Co-habiting Phloem- and Woodboring Beetles, and their Fungal Associates in southern Ontario by Kathleen Ryan A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Faculty of Forestry University of Toronto ©Copyright by Kathleen Ryan 2011 Interactions between the Woodwasp Sirex noctilio and Co-habiting Phloem- and Woodboring Beetles, and their Fungal Associates in southern Ontario Kathleen Ryan Doctor of Philosophy Faculty of Forestry University of Toronto 2011 Abstract In its introduced southern hemisphere range, Sirex noctilio causes considerable mortality in non-native pine forests. In its native Eurasian range however, S. noctilio is of little concern perhaps due to interactions with a well-developed community of pine-inhabiting insects and their associated microorganisms. If such interactions occur, they may limit the woodwasp’s impact in its newly introduced range in North America. My research addresses two broad questions: 1) Does S. noctilio share its habitat with other insects and if so, with whom? 2) Is there evidence that co-habitants affect S. noctilio , and if so how might such interactions occur? Field studies undertaken to describe the woodwasp’s host-attack ecology in Pinus sylvestris showed S. noctilio activity occurred between mid-July and late August, and other phloem- and woodborers sometimes entered the tree after the woodwasp. Tree mortality occurred from two weeks to several months after initial woodwasp symptoms. Suppressed or intermediate trees, those with ≤ 25% residual foliage, or those with stem injury or previous woodwasp symptoms were most likely to have symptoms of woodwasp attack.
    [Show full text]