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Wyka S, Mondo S, Liu M, Nalam V, Broders K. A large accessory genome and high recombination rates may influence global distribution and broad host range of the fungal plant pathogen Claviceps purpurea. PLoS One 2022; 17:e0263496. [PMID: 35143550 PMCID: PMC8830672 DOI: 10.1371/journal.pone.0263496] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/20/2022] [Indexed: 11/18/2022] Open
Abstract
Pangenome analyses are increasingly being utilized to study the evolution of eukaryotic organisms. While pangenomes can provide insight into polymorphic gene content, inferences about the ecological and adaptive potential of such organisms also need to be accompanied by additional supportive genomic analyses. In this study we constructed a pangenome of Claviceps purpurea from 24 genomes and examined the positive selection and recombination landscape of an economically important fungal organism for pharmacology and agricultural research. Together, these analyses revealed that C. purpurea has a relatively large accessory genome (~ 38%), high recombination rates (ρ = 0.044), and transposon mediated gene duplication. However, due to observations of relatively low transposable element (TE) content (8.8%) and a lack of variability in genome sizes, prolific TE expansion may be controlled by frequent recombination. We additionally identified that within the ergoline biosynthetic cluster the lpsA1 and lpsA2 were the result of a recombination event. However, the high recombination rates observed in C. purpurea may be influencing an overall trend of purifying selection across the genome. These results showcase the use of selection and recombination landscapes to identify mechanisms contributing to pangenome structure and primary factors influencing the evolution of an organism.
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Affiliation(s)
- Stephen Wyka
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Stephen Mondo
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
- United States Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - Miao Liu
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Canada
| | - Vamsi Nalam
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kirk Broders
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL, United States of America
- Smithsonian Tropical Research Institute, Apartado Panamá, República de Panamá
- * E-mail:
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Tente E, Ereful N, Rodriguez AC, Grant P, O'Sullivan DM, Boyd LA, Gordon A. Reprogramming of the wheat transcriptome in response to infection with Claviceps purpurea, the causal agent of ergot. BMC PLANT BIOLOGY 2021; 21:316. [PMID: 34215204 PMCID: PMC8252325 DOI: 10.1186/s12870-021-03086-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/07/2021] [Indexed: 06/02/2023]
Abstract
BACKGROUND Ergot, caused by the fungal pathogen Claviceps purpurea, infects the female flowers of a range of cereal crops, including wheat. To understand the interaction between C. purpurea and hexaploid wheat we undertook an extensive examination of the reprogramming of the wheat transcriptome in response to C. purpurea infection through floral tissues (i.e. the stigma, transmitting and base ovule tissues of the ovary) and over time. RESULTS C. purpurea hyphae were observed to have grown into and down the stigma at 24 h (H) after inoculation. By 48H hyphae had grown through the transmitting tissue into the base, while by 72H hyphae had surrounded the ovule. By 5 days (D) the ovule had been replaced by fungal tissue. Differential gene expression was first observed at 1H in the stigma tissue. Many of the wheat genes differentially transcribed in response to C. purpurea infection were associated with plant hormones and included the ethylene (ET), auxin, cytokinin, gibberellic acid (GA), salicylic acid and jasmonic acid (JA) biosynthetic and signaling pathways. Hormone-associated genes were first detected in the stigma and base tissues at 24H, but not in the transmitting tissue. Genes associated with GA and JA pathways were seen in the stigma at 24H, while JA and ET-associated genes were identified in the base at 24H. In addition, several defence-related genes were differential expressed in response to C. purpurea infection, including antifungal proteins, endocytosis/exocytosis-related proteins, NBS-LRR class proteins, genes involved in programmed cell death, receptor protein kinases and transcription factors. Of particular interest was the identification of differential expression of wheat genes in the base tissue well before the appearance of fungal hyphae, suggesting that a mobile signal, either pathogen or plant-derived, is delivered to the base prior to colonisation. CONCLUSIONS Multiple host hormone biosynthesis and signalling pathways were significantly perturbed from an early stage in the wheat - C. purpurea interaction. Differential gene expression at the base of the ovary, ahead of arrival of the pathogen, indicated the potential presence of a long-distance signal modifying host gene expression.
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Affiliation(s)
- Eleni Tente
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Nelzo Ereful
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Philippine Genome Center, Plant Physiology Laboratory, Institute of Plant Breeding, University of the Philippines, Los Baños, Laguna, The Philippines
| | | | - Paul Grant
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
- Present Address: Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK
| | - Donal M O'Sullivan
- School of Agriculture, Policy and Development, University of Reading, Whiteknights, Reading, RG6 6AR, UK
| | - Lesley A Boyd
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK.
| | - Anna Gordon
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
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Wyka SA, Mondo SJ, Liu M, Dettman J, Nalam V, Broders KD. Whole-Genome Comparisons of Ergot Fungi Reveals the Divergence and Evolution of Species within the Genus Claviceps Are the Result of Varying Mechanisms Driving Genome Evolution and Host Range Expansion. Genome Biol Evol 2021; 13:evaa267. [PMID: 33512490 PMCID: PMC7883665 DOI: 10.1093/gbe/evaa267] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/26/2022] Open
Abstract
The genus Claviceps has been known for centuries as an economically important fungal genus for pharmacology and agricultural research. Only recently have researchers begun to unravel the evolutionary history of the genus, with origins in South America and classification of four distinct sections through ecological, morphological, and metabolic features (Claviceps sects. Citrinae, Paspalorum, Pusillae, and Claviceps). The first three sections are additionally characterized by narrow host range, whereas section Claviceps is considered evolutionarily more successful and adaptable as it has the largest host range and biogeographical distribution. However, the reasons for this success and adaptability remain unclear. Our study elucidates factors influencing adaptability by sequencing and annotating 50 Claviceps genomes, representing 21 species, for a comprehensive comparison of genome architecture and plasticity in relation to host range potential. Our results show the trajectory from specialized genomes (sects. Citrinae and Paspalorum) toward adaptive genomes (sects. Pusillae and Claviceps) through colocalization of transposable elements around predicted effectors and a putative loss of repeat-induced point mutation resulting in unconstrained tandem gene duplication coinciding with increased host range potential and speciation. Alterations of genomic architecture and plasticity can substantially influence and shape the evolutionary trajectory of fungal pathogens and their adaptability. Furthermore, our study provides a large increase in available genomic resources to propel future studies of Claviceps in pharmacology and agricultural research, as well as, research into deeper understanding of the evolution of adaptable plant pathogens.
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Affiliation(s)
- Stephen A Wyka
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Stephen J Mondo
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
- U.S. Department of Energy Joint Genome Institute, Berkeley, California, USA
| | - Miao Liu
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada
| | - Jeremy Dettman
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada
| | - Vamsi Nalam
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Kirk D Broders
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
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Scholthof KBG, Irigoyen S, Catalan P, Mandadi KK. Brachypodium: A Monocot Grass Model Genus for Plant Biology. THE PLANT CELL 2018; 30:1673-1694. [PMID: 29997238 PMCID: PMC6139682 DOI: 10.1105/tpc.18.00083] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/25/2018] [Accepted: 07/11/2018] [Indexed: 05/21/2023]
Abstract
The genus Brachypodium represents a model system that is advancing our knowledge of the biology of grasses, including small grains, in the postgenomics era. The most widely used species, Brachypodium distachyon, is a C3 plant that is distributed worldwide. B. distachyon has a small genome, short life cycle, and small stature and is amenable to genetic transformation. Due to the intensive and thoughtful development of this grass as a model organism, it is well-suited for laboratory and field experimentation. The intent of this review is to introduce this model system genus and describe some key outcomes of nearly a decade of research since the first draft genome sequence of the flagship species, B. distachyon, was completed. We discuss characteristics and features of B. distachyon and its congeners that make the genus a valuable model system for studies in ecology, evolution, genetics, and genomics in the grasses, review current hot topics in Brachypodium research, and highlight the potential for future analysis using this system in the coming years.
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Affiliation(s)
- Karen-Beth G Scholthof
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
| | - Sonia Irigoyen
- Texas A&M AgriLife Research and Extension Center, Weslaco, Texas 78596
| | - Pilar Catalan
- Universidad de Zaragoza-Escuela Politécnica Superior de Huesca, 22071 Huesca, Spain
- Grupo de Bioquímica, Biofísica y Biología Computacional (BIFI, UNIZAR), Unidad Asociada al CSIC, Zaragoza E-50059, Spain
- Institute of Biology, Tomsk State University, Tomsk 634050, Russia
| | - Kranthi K Mandadi
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843
- Texas A&M AgriLife Research and Extension Center, Weslaco, Texas 78596
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Powell JJ, Carere J, Sablok G, Fitzgerald TL, Stiller J, Colgrave ML, Gardiner DM, Manners JM, Vogel JP, Henry RJ, Kazan K. Transcriptome analysis of Brachypodium during fungal pathogen infection reveals both shared and distinct defense responses with wheat. Sci Rep 2017; 7:17212. [PMID: 29222453 PMCID: PMC5722949 DOI: 10.1038/s41598-017-17454-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/26/2017] [Indexed: 11/09/2022] Open
Abstract
Fusarium crown rot (FCR) of wheat and barley, predominantly caused by the fungal pathogen Fusarium pseudograminearum, is a disease of economic significance. The quantitative nature of FCR resistance within cultivated wheat germplasm has significantly limited breeding efforts to enhanced FCR resistance in wheat. In this study, we characterized the molecular responses of Brachypodium distachyon (Brachypodium hereafter) to F. pseudograminearum infection using RNA-seq to determine whether Brachypodium can be exploited as a model system towards better understanding of F. pseudograminearum-wheat interaction. The transcriptional response to infection in Brachypodium was strikingly similar to that previously reported in wheat, both in shared expression patterns of wheat homologs of Brachypodium genes and functional overlap revealed through comparative gene ontology analysis in both species. Metabolites produced by various biosynthetic pathways induced in both wheat and Brachypodium were quantified, revealing a high degree of overlap between these two species in metabolic response to infection but also showed Brachypodium does not produce certain defence-related metabolites found in wheat. Functional analyses of candidate genes identified in this study will improve our understanding of resistance mechanisms and may lead to the development of new strategies to protect cereal crops from pathogen infection.
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Affiliation(s)
- Jonathan J Powell
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia.
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), University of Queensland, St Lucia, 4067, Queensland, Australia.
| | - Jason Carere
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia
| | - Gaurav Sablok
- Plant Functional Biology and Climate Change Cluster (C3), University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Sydney, Australia
| | - Timothy L Fitzgerald
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia
| | - Jiri Stiller
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia
| | - Michelle L Colgrave
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia
| | - Donald M Gardiner
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia
| | - John M Manners
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, Black Mountain, Australian Capital Territory, 2601, Australia
| | - John P Vogel
- Joint Genome Institute, United States Department of Energy, Walnut Creek, CA, 94598, USA
| | - Robert J Henry
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), University of Queensland, St Lucia, 4067, Queensland, Australia
| | - Kemal Kazan
- Commonwealth Scientific and Industrial Research Organization Agriculture and Food, St Lucia, Queensland, 4067, Australia.
- Queensland Alliance for Agriculture and Food Innovation (QAAFI), University of Queensland, St Lucia, 4067, Queensland, Australia.
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