DOCSLIB.ORG

Functional Characterization of Polyketide-Derived

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Functional Characterization of Polyketide-Derived FUNCTIONAL CHARACTERIZATION OF POLYKETIDE-DERIVED SECONDARY METABOLITES SOLANAPYRONES PRODUCED BY THE CHICKPEA BLIGHT PATHOGEN, ASCOCHYTA RABIEI: GENETICS AND CHEMICAL ECOLOGY By WONYONG KIM A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY Department of Plant Pathology AUGUST 2015 To the Faculty of Washington State University: The members of the Committee appointed to examine the dissertation of WONYONG KIM find it satisfactory and recommend that it be accepted ___________________________________ Weidong Chen, Ph.D., Chair ___________________________________ Tobin L. Peever, Ph.D. ___________________________________ George J. Vandemark, Ph.D. ___________________________________ Lee A. Hadwiger, Ph.D. ___________________________________ Ming Xian, Ph.D. ii ACKNOWLEDGEMENTS I take this opportunity to thank my major advisor, Dr. Weidong Chen. I have learned a tremendous amount from him in framing hypothesis and critical thinking in science. He gave me every possible opportunity to attend conferences to present my research and interact with scientific communities. I would also like to thank my committee members Drs. Tobin L. Peever, George J. Va ndemark, Lee A. Hadwiger and Ming Xian for their open-door policy when questions arose and for giving me ideas and suggestions that helped develop this dissertation research. I am very fortunate to have such a nice group of committee members who are experts each in their own fields such as Systematics, Genetics, Molecular Biology and Chemistry. Without their expertise and helps the research presented in this dissertation could not have been carried out. I thank to Drs. Jeong-Jin Park and Chung-Min Park for long term collaboration during my doctoral study and being as good friends. Drs. Frank M. Dugan and Akamatsu O. Hajime were also invaluable sources of advice and research materials. I thank to Dr. Lori M. Carris as her Mycology class introduced me to the wondrous world of fungi. I am also appreciative of the the support that I received from the Department of Plant Pathology in Washington State University, the USDA Cool Season Food Legume Research Program, and the USA Dry Pea and Lentil Council. Special thanks to my labmates, Liangsheng Xu, Renuka Attanayake, and Tony Chen, for their technical as well as emotional supports. iii Lastly, but most importantly, I thank my parents, Hyung-wook Kim and Seong-joo Yeo, for their loving support and continuous sacrifices throughout my life. They from an early age gave me inspiration to study agricultural science and be a person who contributes to the society in which we live. This encouraged me to continue during rough times. Special acknowledgement goes to my wife, Eunju Nam, for her understanding, encouragement and love, and lots of love to our son, Jung-wee. iv FUNCTIONAL CHARACTERIZATION OF POLYKETIDE-DERIVED SECONDARY METABOLITES SOLANAPYRONES PRODUCED BY THE CHICKPEA BLIGHT PATHOGEN, ASCOCHYTA RABIEI: GENETICS AND CHEMICAL ECOLOGY Abstract by Wonyong Kim, Ph.D. Washington State University August 2015 Chair: Weidong Chen Ascochyta rabiei causes Ascochyta blight of chickpea. The pathogen is known to produce polyketide-derived secondary metabolites, solanapyrones A, B and C, of which solanapyrone A has long been considered a key virulence factor in the chickpea-A. rabiei interaction, due to its phytotoxicity to chickpea. In order to determine the role of solanapyrones during infection process, solanapyrone-minus mutants were generated from A. rabiei strains of different pathotypes by targeting sol5 and sol4 genes, which encode the last step enzyme and a pathway-specific regulator for solanapyrone biosynthesis, respectively. In addition, phytotoxicity of solanapyrones was examined with various legumes including chickpea plants with varying degree of resistance to the disease. As a result, purified solanapyrone A showed a broad spectrum of phytotoxicity, causing necrotic lesions on all tested plants. The resulting solanapyrone-minus mutants were equally virulent as their corresponding wild-type progenitors, indicating that v solanapyrone A is neither a host-selective toxin nor a virulence factor of A. rabiei. Despite the dispensability in parasitic growth of the pathogen, solanapyrones are produced by all strains investigated in this and several previous studies. The universal production of solanapyrones prompted us to examine possible ecological roles other than parasitism. Synteny analyses of A. rabiei genome with genomes of related species revealed that the solanapyrone biosynthesis gene cluster was placed in a ‘genomic island’, where genes implicated in niche adaptation are often found. The expressions levels of the solanapyrone cluster genes were high during saprobic growth, but negligible during infection processes. Also, the gene expressions culminated at the formation of pycnidia, indicating that solanapyrones are produced in a growth and tissue-specific manner. To investigate ecological roles of solanapyrones, wild-type strains or solanapyrone-minus mutants were co-cultured with saprobic fungi that have been isolated from chickpea debris left in a field. Wild-type strains effectively suppressed the growth of the saprobic fungi, whereas solanapyrone-minus mutants did not. The half maximal inhibitory concentration of solanapyrone A against the saprobic fungi ranged from 50 to 80 μM. These results suggest that solanapyrone A plays an important role in competition and presumably in survival of the pathogen in nature. vi TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ..................................................................................................... iii ABSTRACT ........................................................................................................................... v LIST OF TABLES ................................................................................................................. x LIST OF FIGURES ............................................................................................................... xi PREFACE .............................................................................................................................. xvii CHAPTER 1: Introduction General Introduction ....................................................................................................... 1 References ...................................................................................................................... 26 CHAPTER 2: Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for pathogenicity Abstract ........................................................................................................................... 38 Introduction .................................................................................................................... 39 Materials and Methods ................................................................................................... 43 Results ............................................................................................................................ 55 Discussion ....................................................................................................................... 62 Acknowledgements ........................................................................................................ 69 References ...................................................................................................................... 85 vii CHAPTER 3: Genomic Analysis of Ascochyta rabiei Identifies Dynamic Genome Environments of Solanapyrone Biosynthesis Gene Cluster and a Novel Type of Pathway-specific Regulator Abstract ........................................................................................................................... 92 Introduction .................................................................................................................... 93 Materials and Methods ................................................................................................... 97 Results ............................................................................................................................ 103 Discussion ....................................................................................................................... 110 Acknowledgements ........................................................................................................ 118 References ...................................................................................................................... 136 CHAPTER 4: Growth and Tissue-specific Production of a Secondary Metabolite, Solanapyrone A, and Its Ecological Role during Saprobic Growth of the Fungal Pathogen, Ascochyta rabiei Abstract ........................................................................................................................... 145 Introduction .................................................................................................................... 146 Materials and Methods ................................................................................................... 149 Results ............................................................................................................................ 156 Discussion ......................................................................................................................
Load more

Recommended publications
  • Biology and Host-Pathogen Interaction of Stagonosporopsis Tanaceti, the Cause of Ray Blight Disease in Pyrethrum
    Biology and host-pathogen interaction of Stagonosporopsis tanaceti, the cause of ray blight in pyrethrum Md Abdullahil Baki Bhuiyan Submitted in total fulfilment of the requirements of the degree of Doctor of Philosophy Faculty of Veterinary and Agricultural Sciences The University of Melbourne April 2017 i Declaration I declare that this thesis includes only my original work in the direction of the degree of Doctor of Philosophy. I also acknowledge all other materials use in the text. The words of this do not exceed 100,000 words. This thesis fulfils the stipulations set out for the degree of Doctor of Philosophy by the University of Melbourne. Md Abdullahil Baki Bhuiyan April 2017 ii Acknowledgements My grateful thanks to my major supervisor Professor Paul Taylor and co-supervisor Dr Marc Nicolas for their scholastic academic guidance and continuous help to accomplish this thesis. My special thanks to Paul for his friendly support, guidance and encouragement. My special thanks to Tim Groom, Manager- Agricultural Businesses, Botanical Resources Australia (BRA) Pty. Ltd. for his judicious suggestions, inspirations and invitation at BRA to discuss my findings with the industry people which made this research worthwhile. Many thanks to our lab managers Carolyn Selway, Michelle Rhee and Martin Ji; Stephen and Priya Chand (Faculty staff), Steven (Glasshouse) for their assistance and continuous support throughout the research period. I would like offer special gratitude to my lab colleagues especially Niloofar, Dina, Eden, Mee-Yung, Sophia, Azin, Jiang, Dilani, Ruvini and Aruni for their friendship and continuous support. I would like to acknowledge with special gratitude the Melbourne International Research Scholarship (MIRS) and Melbourne International Fee Remission Scholarship (MIFRS) awarded by the University of Melbourne and financial support from BRA.
    [Show full text]
  • Chapter 11 Marine Fungi Associated with Antarctic Macroalgae
    Chapter 11 Marine Fungi Associated with Antarctic Macroalgae Mayara B. Ogaki, Maria T. de Paula, Daniele Ruas, Franciane M. Pellizzari, César X. García-Laviña, and Luiz H. Rosa Abstract Fungi are well known for their important roles in terrestrial ecosystems, but filamentous and yeast forms are also active components of microbial communi- ties from marine ecosystems. Marine fungi are particularly abundant and relevant in coastal systems where they can be found in association with large organic substrata, like seaweeds. Antarctica is a rather unexplored region of the planet that is being influenced by strong and rapid climate change. In the past decade, several efforts have been made to get a thorough inventory of marine fungi from different environ- ments, with a particular emphasis on those associated with the large communities of seaweeds that abound in littoral and infralittoral ecosystems. The algicolous fungal communities obtained were characterized by a few dominant species and a large number of singletons, as well as a balance among endemic, indigenous, and cold-­ adapted cosmopolitan species. The long-term monitoring of this balance and the dynamics of richness, dominance, and distributional patterns of these algicolous fungal communities is proposed to understand and model the influence of climate change on the maritime Antarctic biota. In addition, several fungal isolates from marine Antarctic environments have shown great potential as producers of bioactive natural products and enzymes and may represent attractive sources of biotechno- logical products. M. B. Ogaki · M. T. de Paula · D. Ruas · L. H. Rosa (*) Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil e-mail: [email protected] F.
    [Show full text]
  • Swim Bladder Mycosis in Farmed Rainbow Trout Oncorhynchus Mykiss Caused by Phoma Herbarum and Experimental Verification of Pathogenicity
    Vol. 138: 237–246, 2020 DISEASES OF AQUATIC ORGANISMS Published online April 9 https://doi.org/10.3354/dao03464 Dis Aquat Org Swim bladder mycosis in farmed rainbow trout Oncorhynchus mykiss caused by Phoma herbarum and experimental verification of pathogenicity Jirˇí Rˇ ehulka1, Alena Kubátová2, Vit Hubka2,3,* 1Department of Zoology, Silesian Museum, 746 01 Opava, Czech Republic 2Department of Botany, Faculty of Science, Charles University, 128 01 Prague 2, Czech Republic 3Laboratory of Fungal Genetics and Metabolism, Institute of Microbiology of the Academy of Sciences of the Czech Republic, v. v. i., 142 20 Prague 4, Czech Republic ABSTRACT: In this study, spontaneous swim bladder mycosis was documented in a farmed finger- ling rainbow trout from a raceway culture system. At necropsy, the gross lesions included a thick- ened swim bladder wall, and the posterior portion of the swim bladder was enlarged due to mas- sive hyperplasia of muscle. A microscopic wet mount examination of the swim bladder contents revealed abundant septate hyphae, and histopathological examination showed periodic acid- Schiff-positive mycelia in the lumen and wall of the swim bladder. Histopathological examination of the thickened posterior swim bladder revealed muscle hyperplasia with expansion by inflam- matory cells. The causative agent was identified as Phoma herbarum through morphological an - alysis and DNA sequencing. The disease was reproduced in rainbow trout fingerlings using intra - peritoneal injection of a spore suspension. Necropsy in dead and moribund fish revealed ex tensive congestion and haemorrhages in the serosa of visceral organs and in liver and abdominal serosan- guinous fluid. Histopathological examination showed severe hepatic congestion, sinusoidal dilata- tion, Kupffer cell reactivity, leukostasis and degenerative changes.
    [Show full text]
  • Isolation and Identification of Fungi from Leaves Infected with False Mildew on Safflower Crops in the Yaqui Valley, Mexico
    Isolation and identification of fungi from leaves infected with false mildew on safflower crops in the Yaqui Valley, Mexico Eber Addi Quintana-Obregón 1, Maribel Plascencia-Jatomea 1, Armando Burgos-Hérnandez 1, Pedro Figueroa-Lopez 2, Mario Onofre Cortez-Rocha 1 1 Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Colonia Centro. C.P. 83000 Hermosillo, Sonora, México. 2 Campo Experimental Norman E. Borlaug-INIFAP. C. Norman Borlaug Km.12 Cd. Obregón, Sonora C.P. 85000 3 1 0 2 Aislamiento e identificación de hongos de las hojas infectadas con la falsa cenicilla , 7 en cultivos de cártamo en el Valle del Yaqui, México 2 - 9 1 Resumen. La falsa cenicilla es una enfermedad que afecta seriamente los cultivos de cártamo en : 7 3 el Valle del Yaqui, México, y es causada por la infección de un hongo perteneciente al género A Ramularia. En el presente estudio, un hongo aislado de hojas contaminadas fue cultivado bajo Í G diferentes condiciones de crecimiento con la finalidad de estudiar su desarrollo micelial y O L producción de esporas, determinándose que el medio sólido de , 18 C de O Septoria tritici ° C I incubación y fotoperiodos de 12 h luz-oscuridad, fueron las condiciones más adecuadas para el M desarrollo del hongo. Este aislamiento fue identificado morfológicamente como Ramularia E D , pero genómicamente como , por lo que no se puede cercosporelloides Cercosporella acroptili A aún concluir que especie causa esta enfermedad. Adicionalmente, en la periferia de las N A C infecciones estudiadas se detectó la presencia de Alternaria tenuissima y Cladosporium I X cladosporioides.
    [Show full text]
  • Biotechnology of Neglected and Underutilized Crops Biotechnology of Neglected and Underutilized Crops Shri Mohan Jain · S
    Shri Mohan Jain · S. Dutta Gupta Editors Biotechnology of Neglected and Underutilized Crops Biotechnology of Neglected and Underutilized Crops Shri Mohan Jain · S. Dutta Gupta Editors Biotechnology of Neglected and Underutilized Crops 1 3 Editors Shri Mohan Jain S. Dutta Gupta Department of Agricultural Sciences Department of Agricultural University of Helsinki and Food Engineering Helsinki Indian Institute of Technology Kharagpur Finland Kharagpur India ISBN 978-94-007-5499-7 ISBN 978-94-007-5500-0 (eBook) DOI 10.1007/978-94-007-5500-0 Springer Dordrecht Heidelberg New York London Library of Congress Control Number: 2013934379 © Springer Science+Business Media Dordrecht 2013 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law.
    [Show full text]
  • Biology and Recent Developments in the Systematics of Phoma, a Complex Genus of Major Quarantine Significance Reviews, Critiques
    Fungal Diversity Reviews, Critiques and New Technologies Reviews, Critiques and New Technologies Biology and recent developments in the systematics of Phoma, a complex genus of major quarantine significance Aveskamp, M.M.1*, De Gruyter, J.1, 2 and Crous, P.W.1 1CBS Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands 2Plant Protection Service (PD), P.O. Box 9102, 6700 HC Wageningen, The Netherlands Aveskamp, M.M., De Gruyter, J. and Crous, P.W. (2008). Biology and recent developments in the systematics of Phoma, a complex genus of major quarantine significance. Fungal Diversity 31: 1-18. Species of the coelomycetous genus Phoma are ubiquitously present in the environment, and occupy numerous ecological niches. More than 220 species are currently recognised, but the actual number of taxa within this genus is probably much higher, as only a fraction of the thousands of species described in literature have been verified in vitro. For as long as the genus exists, identification has posed problems to taxonomists due to the asexual nature of most species, the high morphological variability in vivo, and the vague generic circumscription according to the Saccardoan system. In recent years the genus was revised in a series of papers by Gerhard Boerema and co-workers, using culturing techniques and morphological data. This resulted in an extensive handbook, the “Phoma Identification Manual” which was published in 2004. The present review discusses the taxonomic revision of Phoma and its teleomorphs, with a special focus on its molecular biology and papers published in the post-Boerema era. Key words: coelomycetes, Phoma, systematics, taxonomy.
    [Show full text]
  • Livro-Inpp.Pdf
    GOVERNMENT OF BRAZIL President of Republic Michel Miguel Elias Temer Lulia Minister for Science, Technology, Innovation and Communications Gilberto Kassab MUSEU PARAENSE EMÍLIO GOELDI Director Nilson Gabas Júnior Research and Postgraduate Coordinator Ana Vilacy Moreira Galucio Communication and Extension Coordinator Maria Emilia Cruz Sales Coordinator of the National Research Institute of the Pantanal Maria de Lourdes Pinheiro Ruivo EDITORIAL BOARD Adriano Costa Quaresma (Instituto Nacional de Pesquisas da Amazônia) Carlos Ernesto G.Reynaud Schaefer (Universidade Federal de Viçosa) Fernando Zagury Vaz-de-Mello (Universidade Federal de Mato Grosso) Gilvan Ferreira da Silva (Embrapa Amazônia Ocidental) Spartaco Astolfi Filho (Universidade Federal do Amazonas) Victor Hugo Pereira Moutinho (Universidade Federal do Oeste Paraense) Wolfgang Johannes Junk (Max Planck Institutes) Coleção Adolpho Ducke Museu Paraense Emílio Goeldi Natural resources in wetlands: from Pantanal to Amazonia Marcos Antônio Soares Mário Augusto Gonçalves Jardim Editors Belém 2017 Editorial Project Iraneide Silva Editorial Production Iraneide Silva Angela Botelho Graphic Design and Electronic Publishing Andréa Pinheiro Photos Marcos Antônio Soares Review Iraneide Silva Marcos Antônio Soares Mário Augusto G.Jardim Print Graphic Santa Marta Dados Internacionais de Catalogação na Publicação (CIP) Natural resources in wetlands: from Pantanal to Amazonia / Marcos Antonio Soares, Mário Augusto Gonçalves Jardim. organizers. Belém : MPEG, 2017. 288 p.: il. (Coleção Adolpho Ducke) ISBN 978-85-61377-93-9 1. Natural resources – Brazil - Pantanal. 2. Amazonia. I. Soares, Marcos Antonio. II. Jardim, Mário Augusto Gonçalves. CDD 333.72098115 © Copyright por/by Museu Paraense Emílio Goeldi, 2017. Todos os direitos reservados. A reprodução não autorizada desta publicação, no todo ou em parte, constitui violação dos direitos autorais (Lei nº 9.610).
    [Show full text]
  • A Mechanistic Weather-Driven Model for Ascochyta Rabiei Infection and Disease Development in Chickpea
    plants Article A Mechanistic Weather-Driven Model for Ascochyta rabiei Infection and Disease Development in Chickpea Irene Salotti and Vittorio Rossi * Department of Sustainable Crop Production (DI.PRO.VES.), Università Cattolica del Sacro Cuore, Via E. Parmense 84, 29122 Piacenza, Italy; [email protected] * Correspondence: [email protected] Abstract: Ascochyta blight caused by Ascochyta rabiei is an important disease of chickpea. By using systems analysis, we retrieved and analyzed the published information on A. rabiei to develop a mechanistic, weather-driven model for the prediction of Ascochyta blight epidemics. The ability of the model to predict primary infections was evaluated using published data obtained from trials conducted in Washington (USA) in 2004 and 2005, Israel in 1996 and 1998, and Spain from 1988 to 1992. The model showed good accuracy and specificity in predicting primary infections. The probability of correctly predicting infections was 0.838 and the probability that there was no infection when not predicted was 0.776. The model’s ability to predict disease progress during the growing season was also evaluated by using data collected in Australia from 1996 to 1998 and in Southern Italy in 2019; a high concordance correlation coefficient (CCC = 0.947) between predicted and observed data was obtained, with an average distance between real and fitted data of root mean square error (RMSE) = 0.103, indicating that the model was reliable, accurate, and robust in predicting seasonal dynamics of Ascochyta blight epidemics. The model could help growers schedule fungicide treatments to control Ascochyta blight on chickpea. Citation: Salotti, I.; Rossi, V.
    [Show full text]
  • Taxonomy and Multigene Phylogenetic Evaluation of Novel Species in Boeremia and Epicoccum with New Records of Ascochyta and Didymella (Didymellaceae)
    Mycosphere 8(8): 1080–1101 (2017) www.mycosphere.org ISSN 2077 7019 Article Doi 10.5943/mycosphere/8/8/9 Copyright © Guizhou Academy of Agricultural Sciences Taxonomy and multigene phylogenetic evaluation of novel species in Boeremia and Epicoccum with new records of Ascochyta and Didymella (Didymellaceae) Jayasiri SC1,2, Hyde KD2,3, Jones EBG4, Jeewon R5, Ariyawansa HA6, Bhat JD7, Camporesi E8 and Kang JC1 1 Engineering and Research Center for Southwest Bio-Pharmaceutical Resources of National Education Ministry of China, Guizhou University, Guiyang, Guizhou Province 550025, P.R. China 2Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand 3World Agro forestry Centre East and Central Asia Office, 132 Lanhei Road, Kunming 650201, P. R. China 4Botany and Microbiology Department, College of Science, King Saud University, Riyadh, 1145, Saudi Arabia 5Department of Health Sciences, Faculty of Science, University of Mauritius, Reduit, Mauritius 6Department of Plant Pathology and Microbiology, College of BioResources and Agriculture, National Taiwan University, No.1, Sec.4, Roosevelt Road, Taipei 106, Taiwan, ROC. 7No. 128/1-J, Azad Housing Society, Curca, P.O. Goa Velha, 403108, India 89A.M.B. Gruppo Micologico Forlivese “Antonio Cicognani”, Via Roma 18, Forlì, Italy; A.M.B. CircoloMicologico “Giovanni Carini”, C.P. 314, Brescia, Italy; Società per gliStudiNaturalisticidella Romagna, C.P. 144, Bagnacavallo (RA), Italy *Correspondence: [email protected] Jayasiri SC, Hyde KD, Jones EBG, Jeewon R, Ariyawansa HA, Bhat JD, Camporesi E, Kang JC 2017 – Taxonomy and multigene phylogenetic evaluation of novel species in Boeremia and Epicoccum with new records of Ascochyta and Didymella (Didymellaceae).
    [Show full text]
  • The Phylogeny of Plant and Animal Pathogens in the Ascomycota
    Physiological and Molecular Plant Pathology (2001) 59, 165±187 doi:10.1006/pmpp.2001.0355, available online at http://www.idealibrary.com on MINI-REVIEW The phylogeny of plant and animal pathogens in the Ascomycota MARY L. BERBEE* Department of Botany, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4, Canada (Accepted for publication August 2001) What makes a fungus pathogenic? In this review, phylogenetic inference is used to speculate on the evolution of plant and animal pathogens in the fungal Phylum Ascomycota. A phylogeny is presented using 297 18S ribosomal DNA sequences from GenBank and it is shown that most known plant pathogens are concentrated in four classes in the Ascomycota. Animal pathogens are also concentrated, but in two ascomycete classes that contain few, if any, plant pathogens. Rather than appearing as a constant character of a class, the ability to cause disease in plants and animals was gained and lost repeatedly. The genes that code for some traits involved in pathogenicity or virulence have been cloned and characterized, and so the evolutionary relationships of a few of the genes for enzymes and toxins known to play roles in diseases were explored. In general, these genes are too narrowly distributed and too recent in origin to explain the broad patterns of origin of pathogens. Co-evolution could potentially be part of an explanation for phylogenetic patterns of pathogenesis. Robust phylogenies not only of the fungi, but also of host plants and animals are becoming available, allowing for critical analysis of the nature of co-evolutionary warfare. Host animals, particularly human hosts have had little obvious eect on fungal evolution and most cases of fungal disease in humans appear to represent an evolutionary dead end for the fungus.
    [Show full text]
  • Draft Genome Sequencing and Secretome Analysis of Fungal
    www.nature.com/scientificreports OPEN Draft genome sequencing and secretome analysis of fungal phytopathogen Ascochyta Received: 28 October 2015 Accepted: 04 April 2016 rabiei provides insight into the Published: 19 April 2016 necrotrophic effector repertoire Sandhya Verma, Rajesh Kumar Gazara, Shadab Nizam, Sabiha Parween, Debasis Chattopadhyay & Praveen Kumar Verma Constant evolutionary pressure acting on pathogens refines their molecular strategies to attain successful pathogenesis. Recent studies have shown that pathogenicity mechanisms of necrotrophic fungi are far more intricate than earlier evaluated. However, only a few studies have explored necrotrophic fungal pathogens. Ascochyta rabiei is a necrotrophic fungus that causes devastating blight disease of chickpea (Cicer arietinum). Here, we report a 34.6 megabase draft genome assembly of A. rabiei. The genome assembly covered more than 99% of the gene space and 4,259 simple sequence repeats were identified in the assembly. A total of 10,596 high confidence protein-coding genes were predicted which includes a large and diverse inventory of secretory proteins, transporters and primary and secondary metabolism enzymes reflecting the necrotrophic lifestyle ofA. rabiei. A wide range of genes encoding carbohydrate- active enzymes capable for degradation of complex polysaccharides were also identified. Comprehensive analysis predicted a set of 758 secretory proteins including both classical and non-classical secreted proteins. Several of these predicted secretory proteins showed high cysteine content and numerous tandem repeats. Together, our analyses would broadly expand our knowledge and offer insights into the pathogenesis and necrotrophic lifestyle of fungal phytopathogens. Chickpea (Cicer arietinum L.), an important high-protein source, is an annual legume crop grown worldwide.
    [Show full text]
  • First Report of Alternaria Carthami Causing Leaf Spots on Carthamus Tinctorius in Brazil
    New Disease Reports (2016) 33, 3. http://dx.doi.org/10.5197/j.2044-0588.2016.033.003 First report of Alternaria carthami causing leaf spots on Carthamus tinctorius in Brazil J.L. Alves 1, R.M. Saraiva 1, E.S.G. Mizubuti 1, S.M.T.P.G. Carneiro 2, L.C. Borsato 2, J.H.C. Woudenberg 3 and V. Lourenço Jr. 4* 1 Universidade Federal de Viçosa, Departamento de Fitopatologia, 36570-000, Viçosa, Minas Gerais, Brazil; 2 Instituto Agronômico do Paraná – IAPAR, Área de Proteção de Plantas, 86047-902, Londrina, Paraná, Brazil; 3 CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD, Utrecht, The Netherlands; 4 Embrapa Hortaliças, 70351-970, Brasília, Distrito Federal, Brazil *E-mail: [email protected] Received: 01 Oct 2015. Published: 22 Jan 2016. Keywords: Alternaria alternata, safflower Carthamus tinctorius (safflower) is an important commercial flower which The fungus was re-isolated from the inoculated plants and the morphology is cultivated mainly for its seeds, from which vegetable oil can be was the same as the inoculated isolate (Fig. 2). No symptoms developed in extracted. In March 2013, approximately 50% of the safflower cv. Goiás at control plants sprayed with distilled water. the Instituto Agronômico do Paraná in Londrina (Paraná, Brazil) showed At least seven species of Alternaria are recorded from C. tinctorius (Farr & brown spots with concentric rings on leaves and elongated or irregular Rossman, 2014). A. carthami is known as a destructive disease of safflower necrotic lesions on petioles, stems and flower heads. One distinct and is recorded worldwide.
    [Show full text]