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Pathogenomics and Management of Fusarium Diseases in Plants. Pathogens 2020; 9:pathogens9050340. [PMID: 32369942 PMCID: PMC7281180 DOI: 10.3390/pathogens9050340] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 12/16/2022] Open
Abstract
There is an urgency to supplant the heavy reliance on chemical control of Fusarium diseases in different economically important, staple food crops due to development of resistance in the pathogen population, the high cost of production to the risk-averse grower, and the concomitant environmental impacts. Pathogenomics has enabled (i) the creation of genetic inventories which identify those putative genes, regulators, and effectors that are associated with virulence, pathogenicity, and primary and secondary metabolism; (ii) comparison of such genes among related pathogens; (iii) identification of potential genetic targets for chemical control; and (iv) better characterization of the complex dynamics of host–microbe interactions that lead to disease. This type of genomic data serves to inform host-induced gene silencing (HIGS) technology for targeted disruption of transcription of select genes for the control of Fusarium diseases. This review discusses the various repositories and browser access points for comparison of genomic data, the strategies for identification and selection of pathogenicity- and virulence-associated genes and effectors in different Fusarium species, HIGS and successful Fusarium disease control trials with a consideration of loss of RNAi, off-target effects, and future challenges in applying HIGS for management of Fusarium diseases.
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52
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Martynov VV, Chizhik VK. Genetics of Pathogen–Host Interaction by the Example of Potato Late Blight Disease. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420030102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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53
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Badet T, Oggenfuss U, Abraham L, McDonald BA, Croll D. A 19-isolate reference-quality global pangenome for the fungal wheat pathogen Zymoseptoria tritici. BMC Biol 2020; 18:12. [PMID: 32046716 PMCID: PMC7014611 DOI: 10.1186/s12915-020-0744-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/27/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The gene content of a species largely governs its ecological interactions and adaptive potential. A species is therefore defined by both core genes shared between all individuals and accessory genes segregating presence-absence variation. There is growing evidence that eukaryotes, similar to bacteria, show intra-specific variability in gene content. However, it remains largely unknown how functionally relevant such a pangenome structure is for eukaryotes and what mechanisms underlie the emergence of highly polymorphic genome structures. RESULTS Here, we establish a reference-quality pangenome of a fungal pathogen of wheat based on 19 complete genomes from isolates sampled across six continents. Zymoseptoria tritici causes substantial worldwide losses to wheat production due to rapidly evolved tolerance to fungicides and evasion of host resistance. We performed transcriptome-assisted annotations of each genome to construct a global pangenome. Major chromosomal rearrangements are segregating within the species and underlie extensive gene presence-absence variation. Conserved orthogroups account for only ~ 60% of the species pangenome. Investigating gene functions, we find that the accessory genome is enriched for pathogenesis-related functions and encodes genes involved in metabolite production, host tissue degradation and manipulation of the immune system. De novo transposon annotation of the 19 complete genomes shows that the highly diverse chromosomal structure is tightly associated with transposable element content. Furthermore, transposable element expansions likely underlie recent genome expansions within the species. CONCLUSIONS Taken together, our work establishes a highly complex eukaryotic pangenome providing an unprecedented toolbox to study how pangenome structure impacts crop-pathogen interactions.
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Affiliation(s)
- Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Leen Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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54
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Badet T, Oggenfuss U, Abraham L, McDonald BA, Croll D. A 19-isolate reference-quality global pangenome for the fungal wheat pathogen Zymoseptoria tritici. BMC Biol 2020; 18:12. [PMID: 32046716 DOI: 10.1101/803098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 01/27/2020] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND The gene content of a species largely governs its ecological interactions and adaptive potential. A species is therefore defined by both core genes shared between all individuals and accessory genes segregating presence-absence variation. There is growing evidence that eukaryotes, similar to bacteria, show intra-specific variability in gene content. However, it remains largely unknown how functionally relevant such a pangenome structure is for eukaryotes and what mechanisms underlie the emergence of highly polymorphic genome structures. RESULTS Here, we establish a reference-quality pangenome of a fungal pathogen of wheat based on 19 complete genomes from isolates sampled across six continents. Zymoseptoria tritici causes substantial worldwide losses to wheat production due to rapidly evolved tolerance to fungicides and evasion of host resistance. We performed transcriptome-assisted annotations of each genome to construct a global pangenome. Major chromosomal rearrangements are segregating within the species and underlie extensive gene presence-absence variation. Conserved orthogroups account for only ~ 60% of the species pangenome. Investigating gene functions, we find that the accessory genome is enriched for pathogenesis-related functions and encodes genes involved in metabolite production, host tissue degradation and manipulation of the immune system. De novo transposon annotation of the 19 complete genomes shows that the highly diverse chromosomal structure is tightly associated with transposable element content. Furthermore, transposable element expansions likely underlie recent genome expansions within the species. CONCLUSIONS Taken together, our work establishes a highly complex eukaryotic pangenome providing an unprecedented toolbox to study how pangenome structure impacts crop-pathogen interactions.
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Affiliation(s)
- Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Leen Abraham
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.
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55
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Fouché S, Badet T, Oggenfuss U, Plissonneau C, Francisco CS, Croll D. Stress-Driven Transposable Element De-repression Dynamics and Virulence Evolution in a Fungal Pathogen. Mol Biol Evol 2020; 37:221-239. [PMID: 31553475 DOI: 10.1093/molbev/msz216] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Transposable elements (TEs) are drivers of genome evolution and affect the expression landscape of the host genome. Stress is a major factor inducing TE activity; however, the regulatory mechanisms underlying de-repression are poorly understood. Plant pathogens are excellent models to dissect the impact of stress on TEs. The process of plant infection induces stress for the pathogen, and virulence factors (i.e., effectors) located in TE-rich regions become expressed. To dissect TE de-repression dynamics and contributions to virulence, we analyzed the TE expression landscape of four strains of the major wheat pathogen Zymoseptoria tritici. We experimentally exposed strains to nutrient starvation and host infection stress. Contrary to expectations, we show that the two distinct conditions induce the expression of different sets of TEs. In particular, the most highly expressed TEs, including miniature inverted-repeat transposable element and long terminal repeat-Gypsy element, show highly distinct de-repression across stress conditions. Both the genomic context of TEs and the genetic background stress (i.e., different strains harboring the same TEs) were major predictors of de-repression under stress. Gene expression profiles under stress varied significantly depending on the proximity to the closest TEs and genomic defenses against TEs were largely ineffective to prevent de-repression. Next, we analyzed the locus encoding the Avr3D1 effector. We show that the insertion and subsequent silencing of TEs in close proximity likely contributed to reduced expression and virulence on a specific wheat cultivar. The complexity of TE responsiveness to stress across genetic backgrounds and genomic locations demonstrates substantial intraspecific genetic variation to control TEs with consequences for virulence.
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Affiliation(s)
- Simone Fouché
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.,Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Thomas Badet
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Clémence Plissonneau
- Plant Pathology, Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | | | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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56
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Frantzeskakis L, Di Pietro A, Rep M, Schirawski J, Wu CH, Panstruga R. Rapid evolution in plant-microbe interactions - a molecular genomics perspective. THE NEW PHYTOLOGIST 2020; 225:1134-1142. [PMID: 31134629 DOI: 10.1111/nph.15966] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/14/2019] [Indexed: 06/09/2023]
Abstract
Rapid (co-)evolution at multiple timescales is a hallmark of plant-microbe interactions. The mechanistic basis for the rapid evolution largely rests on the features of the genomes of the interacting partners involved. Here, we review recent insights into genomic characteristics and mechanisms that enable rapid evolution of both plants and phytopathogens. These comprise fresh insights in allelic series of matching pairs of resistance and avirulence genes, the generation of novel pathogen effectors, the recently recognised small RNA warfare, and genomic aspects of secondary metabolite biosynthesis. In addition, we discuss the putative contributions of permissive host environments, transcriptional plasticity and the role of ploidy on the interactions. We conclude that the means underlying the rapid evolution of plant-microbe interactions are multifaceted and depend on the particular nature of each interaction.
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Affiliation(s)
| | - Antonio Di Pietro
- Departamento de Genética and Campus de Excelencia Agroalimentario (ceiA3), Universidad de Córdoba, 14071, Córdoba, Spain
| | - Martijn Rep
- Faculty of Science, Swammerdam Institute for Life Sciences, University of Amsterdam, PO Box 94215, 1090 GE, Amsterdam, the Netherlands
| | - Jan Schirawski
- Microbial Genetics, Institute of Applied Microbiology, RWTH Aachen University, Aachen, Germany
| | - Chih-Hang Wu
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen University, Worringerweg 1, Aachen, 52056, Germany
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57
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Tralamazza SM, Rocha LO, Oggenfuss U, Corrêa B, Croll D. Complex Evolutionary Origins of Specialized Metabolite Gene Cluster Diversity among the Plant Pathogenic Fungi of the Fusarium graminearum Species Complex. Genome Biol Evol 2019; 11:3106-3122. [PMID: 31609418 PMCID: PMC6836718 DOI: 10.1093/gbe/evz225] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2019] [Indexed: 12/26/2022] Open
Abstract
Fungal genomes encode highly organized gene clusters that underlie the production of specialized (or secondary) metabolites. Gene clusters encode key functions to exploit plant hosts or environmental niches. Promiscuous exchange among species and frequent reconfigurations make gene clusters some of the most dynamic elements of fungal genomes. Despite evidence for high diversity in gene cluster content among closely related strains, the microevolutionary processes driving gene cluster gain, loss, and neofunctionalization are largely unknown. We analyzed the Fusarium graminearum species complex (FGSC) composed of plant pathogens producing potent mycotoxins and causing Fusarium head blight on cereals. We de novo assembled genomes of previously uncharacterized FGSC members (two strains of F. austroamericanum, F. cortaderiae, and F. meridionale). Our analyses of 8 species of the FGSC in addition to 15 other Fusarium species identified a pangenome of 54 gene clusters within FGSC. We found that multiple independent losses were a key factor generating extant cluster diversity within the FGSC and the Fusarium genus. We identified a modular gene cluster conserved among distantly related fungi, which was likely reconfigured to encode different functions. We also found strong evidence that a rare cluster in FGSC was gained through an ancient horizontal transfer between bacteria and fungi. Chromosomal rearrangements underlying cluster loss were often complex and were likely facilitated by an enrichment in specific transposable elements. Our findings identify important transitory stages in the birth and death process of specialized metabolism gene clusters among very closely related species.
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Affiliation(s)
- Sabina Moser Tralamazza
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Brazil
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Switzerland
| | - Liliana Oliveira Rocha
- Food Engineering Faculty, Department of Food Science, University of Campinas, Av. Monteiro Lobato, Brazil
| | - Ursula Oggenfuss
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Switzerland
| | - Benedito Corrêa
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Brazil
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchatel, Switzerland
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58
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Derbyshire M, Mbengue M, Barascud M, Navaud O, Raffaele S. Small RNAs from the plant pathogenic fungus Sclerotinia sclerotiorum highlight host candidate genes associated with quantitative disease resistance. MOLECULAR PLANT PATHOLOGY 2019; 20:1279-1297. [PMID: 31361080 PMCID: PMC6715603 DOI: 10.1111/mpp.12841] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Fungal plant pathogens secrete effector proteins and metabolites to cause disease. Additionally, some species transfer small RNAs (sRNAs) into plant cells to silence host mRNAs through complementary base pairing and suppress plant immunity. The fungus Sclerotinia sclerotiorum infects over 600 plant species, but little is known about the molecular processes that govern interactions with its many hosts. In particular, evidence for the production of sRNAs by S. sclerotiorum during infection is lacking. We sequenced sRNAs produced by S. sclerotiorum in vitro and during infection of two host species, Arabidopsis thaliana and Phaseolus vulgaris. We found that S. sclerotiorum produces at least 374 distinct highly abundant sRNAs during infection, mostly originating from repeat-rich plastic genomic regions. We predicted the targets of these sRNAs in A. thaliana and found that these genes were significantly more down-regulated during infection than the rest of the genome. Predicted targets of S. sclerotiorum sRNAs in A. thaliana were enriched for functional domains associated with plant immunity and were more strongly associated with quantitative disease resistance in a genome-wide association study (GWAS) than the rest of the genome. Mutants in A. thaliana predicted sRNA target genes SERK2 and SNAK2 were more susceptible to S. sclerotiorum than wild-type, suggesting that S. sclerotiorum sRNAs may contribute to the silencing of immune components in plants. The prediction of fungal sRNA targets in plant genomes can be combined with other global approaches, such as GWAS, to assist in the identification of plant genes involved in quantitative disease resistance.
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Affiliation(s)
- Mark Derbyshire
- Centre for Crop and Disease ManagementCurtin UniversityPerthWestern AustraliaAustralia
| | - Malick Mbengue
- Laboratoire des Interactions Plantes Micro‐organismesINRA, CNRS, Université de ToulouseCastanet TolosanFrance
| | - Marielle Barascud
- Laboratoire des Interactions Plantes Micro‐organismesINRA, CNRS, Université de ToulouseCastanet TolosanFrance
| | - Olivier Navaud
- Laboratoire des Interactions Plantes Micro‐organismesINRA, CNRS, Université de ToulouseCastanet TolosanFrance
| | - Sylvain Raffaele
- Laboratoire des Interactions Plantes Micro‐organismesINRA, CNRS, Université de ToulouseCastanet TolosanFrance
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59
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Hartmann FE, Rodríguez de la Vega RC, Carpentier F, Gladieux P, Cornille A, Hood ME, Giraud T. Understanding Adaptation, Coevolution, Host Specialization, and Mating System in Castrating Anther-Smut Fungi by Combining Population and Comparative Genomics. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:431-457. [PMID: 31337277 DOI: 10.1146/annurev-phyto-082718-095947] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Anther-smut fungi provide a powerful system to study host-pathogen specialization and coevolution, with hundreds of Microbotryum species specialized on diverse Caryophyllaceae plants, castrating their hosts through manipulation of the hosts' reproductive organs to facilitate disease transmission. Microbotryum fungi have exceptional genomic characteristics, including dimorphic mating-type chromosomes, that make this genus anexcellent model for studying the evolution of mating systems and their influence on population genetics structure and adaptive potential. Important insights into adaptation, coevolution, host specialization, and mating system evolution have been gained using anther-smut fungi, with new insights made possible by the recent advent of genomic approaches. We illustrate with Microbotryum case studies how using a combination of comparative genomics, population genomics, and transcriptomics approaches enables the integration of different evolutionary perspectives across different timescales. We also highlight current challenges and suggest future studies that will contribute to advancing our understanding of the mechanisms underlying adaptive processes in populations of fungal pathogens.
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Affiliation(s)
- Fanny E Hartmann
- Ecologie Systématique Evolution, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, 91400 Orsay, France;
| | | | - Fantin Carpentier
- Ecologie Systématique Evolution, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, 91400 Orsay, France;
| | - Pierre Gladieux
- UMR BGPI, Univ. Montpellier, INRA, CIRAD, Montpellier SupAgro, 34398 Montpellier, France
| | - Amandine Cornille
- Génétique Quantitative et Evolution-Le Moulon, INRA; Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Michael E Hood
- Biology Department, Amherst College, Amherst, Massachusetts 01002-5000, USA
| | - Tatiana Giraud
- Ecologie Systématique Evolution, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, 91400 Orsay, France;
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60
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Chen XR, Zhang Y, Li HY, Zhang ZH, Sheng GL, Li YP, Xing YP, Huang SX, Tao H, Kuan T, Zhai Y, Ma W. The RXLR Effector PcAvh1 Is Required for Full Virulence of Phytophthora capsici. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:986-1000. [PMID: 30811314 DOI: 10.1094/mpmi-09-18-0251-r] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Plant pathogens employ diverse secreted effector proteins to manipulate host physiology and defense in order to foster diseases. The destructive Phytophthora pathogens encode hundreds of cytoplasmic effectors, which are believed to function inside the plant cells. Many of these cytoplasmic effectors contain the conserved N-terminal RXLR motif. Understanding the virulence function of RXLR effectors will provide important knowledge of Phytophthora pathogenesis. Here, we report the characterization of RXLR effector PcAvh1 from the broad-host range pathogen Phytophthora capsici. Only expressed during infection, PcAvh1 is quickly induced at the early infection stages. CRISPR/Cas9-knockout of PcAvh1 in P. capsici severely impairs virulence while overexpression enhances disease development in Nicotiana benthamiana and bell pepper, demonstrating that PcAvh1 is an essential virulence factor. Ectopic expression of PcAvh1 induces cell death in N. benthamiana, tomato, and bell pepper. Using yeast two-hybrid screening, we found that PcAvh1 interacts with the scaffolding subunit of the protein phosphatase 2A (PP2Aa) in plant cells. Virus-induced gene silencing of PP2Aa in N. benthamiana attenuates resistance to P. capsici and results in dwarfism, suggesting that PP2Aa regulates plant immunity and growth. Collectively, these results suggest that PcAvh1 contributes to P. capsici infection, probably through its interaction with host PP2Aa.
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Affiliation(s)
- Xiao-Ren Chen
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
- 2Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
| | - Ye Zhang
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Hai-Yang Li
- 3College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu Province 210095, China
| | - Zi-Hui Zhang
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Gui-Lin Sheng
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Yan-Peng Li
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Yu-Ping Xing
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Shen-Xin Huang
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Hang Tao
- 1College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu Province 225009, China
| | - Tung Kuan
- 2Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
| | - Yi Zhai
- 2Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
| | - Wenbo Ma
- 2Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
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61
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Transposable Elements Adaptive Role in Genome Plasticity, Pathogenicity and Evolution in Fungal Phytopathogens. Int J Mol Sci 2019; 20:ijms20143597. [PMID: 31340492 PMCID: PMC6679389 DOI: 10.3390/ijms20143597] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/18/2019] [Accepted: 06/25/2019] [Indexed: 01/08/2023] Open
Abstract
Transposable elements (TEs) are agents of genetic variability in phytopathogens as they are a source of adaptive evolution through genome diversification. Although many studies have uncovered information on TEs, the exact mechanism behind TE-induced changes within the genome remains poorly understood. Furthermore, convergent trends towards bigger genomes, emergence of novel genes and gain or loss of genes implicate a TE-regulated genome plasticity of fungal phytopathogens. TEs are able to alter gene expression by revamping the cis-regulatory elements or recruiting epigenetic control. Recent findings show that TEs recruit epigenetic control on the expression of effector genes as part of the coordinated infection strategy. In addition to genome plasticity and diversity, fungal pathogenicity is an area of economic concern. A survey of TE distribution suggests that their proximity to pathogenicity genes TEs may act as sites for emergence of novel pathogenicity factors via nucleotide changes and expansion or reduction of the gene family. Through a systematic survey of literature, we were able to conclude that the role of TEs in fungi is wide: ranging from genome plasticity, pathogenicity to adaptive behavior in evolution. This review also identifies the gaps in knowledge that requires further elucidation for a better understanding of TEs' contribution to genome architecture and versatility.
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62
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van der Nest MA, Steenkamp ET, Roodt D, Soal NC, Palmer M, Chan WY, Wilken PM, Duong TA, Naidoo K, Santana QC, Trollip C, De Vos L, van Wyk S, McTaggart AR, Wingfield MJ, Wingfield BD. Genomic analysis of the aggressive tree pathogen Ceratocystis albifundus. Fungal Biol 2019; 123:351-363. [PMID: 31053324 DOI: 10.1016/j.funbio.2019.02.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 12/13/2022]
Abstract
The overall goal of this study was to determine whether the genome of an important plant pathogen in Africa, Ceratocystis albifundus, is structured into subgenomic compartments, and if so, to establish how these compartments are distributed across the genome. For this purpose, the publicly available genome of C. albifundus was complemented with the genome sequences for four additional isolates using the Illumina HiSeq platform. In addition, a reference genome for one of the individuals was assembled using both PacBio and Illumina HiSeq technologies. Our results showed a high degree of synteny between the five genomes, although several regions lacked detectable long-range synteny. These regions were associated with the presence of accessory genes, lower genetic similarity, variation in read-map depth, as well as transposable elements and genes associated with host-pathogen interactions (e.g. effectors and CAZymes). Such patterns are regarded as hallmarks of accelerated evolution, particularly of accessory subgenomic compartments in fungal pathogens. Our findings thus showed that the genome of C. albifundus is made-up of core and accessory subgenomic compartments, which is an important step towards characterizing its pangenome. This study also highlights the value of comparative genomics for understanding mechanisms that may underly and influence the biology and evolution of pathogens.
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Affiliation(s)
- Magriet A van der Nest
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Danielle Roodt
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Nicole C Soal
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Wai-Yin Chan
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - P Markus Wilken
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tuan A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Kershney Naidoo
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Quentin C Santana
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Conrad Trollip
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Lieschen De Vos
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Stephanie van Wyk
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Alistair R McTaggart
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Michael J Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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63
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Mohd-Assaad N, McDonald BA, Croll D. The emergence of the multi-species NIP1 effector in Rhynchosporium was accompanied by high rates of gene duplications and losses. Environ Microbiol 2019; 21:2677-2695. [PMID: 30838748 DOI: 10.1111/1462-2920.14583] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 02/23/2019] [Accepted: 03/04/2019] [Indexed: 01/28/2023]
Abstract
Plant pathogens secrete effector proteins to manipulate the host and facilitate infection. Cognate hosts trigger strong defence responses upon detection of these effectors. Consequently, pathogens and hosts undergo rapid coevolutionary arms races driven by adaptive evolution of effectors and receptors. Because of their high rate of turnover, most effectors are thought to be species-specific and the evolutionary trajectories are poorly understood. Here, we investigate the necrosis-inducing protein 1 (NIP1) effector in the multihost pathogen genus Rhynchosporium. We retraced the evolutionary history of the NIP1 locus using whole-genome assemblies of 146 strains covering four closely related species. NIP1 orthologues were present in all species but the locus consistently segregated presence-absence polymorphisms suggesting long-term balancing selection. We also identified previously unknown paralogues of NIP1 that were shared among multiple species and showed substantial copy-number variation within R. commune. The NIP1A paralogue was under significant positive selection suggesting that NIP1A is the dominant effector variant coevolving with host immune receptors. Consistent with this prediction, we found that copy number variation at NIP1A had a stronger effect on virulence than NIP1B. Our analyses unravelled the origins and diversification mechanisms of a pathogen effector family shedding light on how pathogens gain adaptive genetic variation.
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Affiliation(s)
- Norfarhan Mohd-Assaad
- Plant Pathology, Institute of Integrative Biology, ETH, Zurich, 8092 Zurich, Switzerland.,School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH, Zurich, 8092 Zurich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
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64
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Tanaka S, Schweizer G, Rössel N, Fukada F, Thines M, Kahmann R. Neofunctionalization of the secreted Tin2 effector in the fungal pathogen Ustilago maydis. Nat Microbiol 2018; 4:251-257. [PMID: 30510169 DOI: 10.1038/s41564-018-0304-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 10/24/2018] [Indexed: 01/23/2023]
Abstract
Plant-pathogenic fungi hijack their hosts by secreting effector proteins. Effectors serve to suppress plant immune responses and modulate the host metabolism to benefit the pathogen. Smut fungi are biotrophic pathogens that also parasitize important cereals, including maize1. Symptom development is usually restricted to the plant inflorescences. Ustilago maydis is an exception in its ability to cause tumours in both inflorescences and leaves of maize, and in inducing anthocyanin biosynthesis through the secreted Tin2 effector2,3. How the unique lifestyle of U. maydis has evolved remains to be elucidated. Here we show that Tin2 in U. maydis has been neofunctionalized. We functionally compared Tin2 effectors of U. maydis and the related smut Sporisorium reilianum, which results in symptoms only in the inflorescences of maize and fails to induce anthocyanin. We show that Tin2 effectors from both fungi target distinct paralogues of a maize protein kinase, leading to stabilization and inhibition, respectively. An ancestral Tin2 effector functionally replaced the virulence function of S. reilianum Tin2 but failed to induce anthocyanin, and was unable to substitute for Tin2 in U. maydis. This shows that Tin2 in U. maydis has acquired a specialized function, probably connected to the distinct pathogenic lifestyle of this fungus.
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Affiliation(s)
- Shigeyuki Tanaka
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Gabriel Schweizer
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.,University of Zurich, Department of Evolutionary Biology and Environmental Studies, Zurich, Switzerland
| | - Nicole Rössel
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Fumi Fukada
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Marco Thines
- Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe University, Frankfurt am Main, Germany.,Senckenberg Biodiversity and Climate Research Center, Frankfurt am Main, Germany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
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65
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Upson JL, Zess EK, Białas A, Wu CH, Kamoun S. The coming of age of EvoMPMI: evolutionary molecular plant-microbe interactions across multiple timescales. CURRENT OPINION IN PLANT BIOLOGY 2018; 44:108-116. [PMID: 29604609 DOI: 10.1016/j.pbi.2018.03.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/06/2018] [Accepted: 03/08/2018] [Indexed: 05/11/2023]
Abstract
Plant-microbe interactions are great model systems to study co-evolutionary dynamics across multiple timescales. However, mechanistic research on plant-microbe interactions has often been conducted with little consideration of evolutionary concepts and methods. Conversely, evolutionary research has rarely integrated the range of mechanisms and models from the molecular plant-microbe interactions field. In recent years, the incipient field of evolutionary molecular plant-microbe interactions (EvoMPMI) has emerged to bridge this gap. Here, we report on some of the recent advances in EvoMPMI. In particular, we highlight new systems to study microbe interactions with early diverging land plants, and new findings from studies of adaptive evolution in pathogens and plants. By linking mechanistic and evolutionary research, EvoMPMI promises to expand our understanding of plant-microbe interactions.
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Affiliation(s)
- Jessica L Upson
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
| | - Erin K Zess
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
| | | | - Chih-Hang Wu
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK
| | - Sophien Kamoun
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK.
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66
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Sabelleck B, Panstruga R. Novel jack-in-the-box effector of the barley powdery mildew pathogen? JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3511-3514. [PMID: 29947808 PMCID: PMC6022647 DOI: 10.1093/jxb/ery192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This article comments on: Nottensteiner M, Zechmann B, McCollum C, Hückelhoven R. 2018. A barley powdery mildew fungus non-autonomous retrotransposon encodes a peptide that supports penetration success on barley. Journal of Experimental Botany 69, 3745–3758.
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Affiliation(s)
- Björn Sabelleck
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg, Aachen, Germany
| | - Ralph Panstruga
- RWTH Aachen University, Institute for Biology I, Unit of Plant Molecular Cell Biology, Worringerweg, Aachen, Germany
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67
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Mohd-Assaad N, McDonald BA, Croll D. Genome-Wide Detection of Genes Under Positive Selection in Worldwide Populations of the Barley Scald Pathogen. Genome Biol Evol 2018; 10:1315-1332. [PMID: 29722810 PMCID: PMC5972619 DOI: 10.1093/gbe/evy087] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2018] [Indexed: 12/29/2022] Open
Abstract
Coevolution between hosts and pathogens generates strong selection pressures to maintain resistance and infectivity, respectively. Genomes of plant pathogens often encode major effect loci for the ability to successfully infect specific host genotypes. Hence, spatial heterogeneity in host genotypes coupled with abiotic factors could lead to locally adapted pathogen populations. However, the genetic basis of local adaptation is poorly understood. Rhynchosporium commune, the pathogen causing barley scald disease, interacts at least partially in a gene-for-gene manner with its host. We analyzed global field populations of 125 R. commune isolates to identify candidate genes for local adaptation. Whole genome sequencing data showed that the pathogen is subdivided into three genetic clusters associated with distinct geographic and climatic regions. Using haplotype-based selection scans applied independently to each genetic cluster, we found strong evidence for selective sweeps throughout the genome. Comparisons of loci under selection among clusters revealed little overlap, suggesting that ecological differences associated with each cluster led to variable selection regimes. The strongest signals of selection were found predominantly in the two clusters composed of isolates from Central Europe and Ethiopia. The strongest selective sweep regions encoded protein functions related to biotic and abiotic stress responses. Selective sweep regions were enriched in genes encoding functions in cellular localization, protein transport activity, and DNA damage responses. In contrast to the prevailing view that a small number of gene-for-gene interactions govern plant pathogen evolution, our analyses suggest that the evolutionary trajectory is largely determined by spatially heterogeneous biotic and abiotic selection pressures.
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Affiliation(s)
- Norfarhan Mohd-Assaad
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Switzerland
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Hartmann FE, Rodríguez de la Vega RC, Brandenburg JT, Carpentier F, Giraud T. Gene Presence-Absence Polymorphism in Castrating Anther-Smut Fungi: Recent Gene Gains and Phylogeographic Structure. Genome Biol Evol 2018; 10:1298-1314. [PMID: 29722826 PMCID: PMC5967549 DOI: 10.1093/gbe/evy089] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2018] [Indexed: 12/14/2022] Open
Abstract
Gene presence-absence polymorphisms segregating within species are a significant source of genetic variation but have been little investigated to date in natural populations. In plant pathogens, the gain or loss of genes encoding proteins interacting directly with the host, such as secreted proteins, probably plays an important role in coevolution and local adaptation. We investigated gene presence-absence polymorphism in populations of two closely related species of castrating anther-smut fungi, Microbotryum lychnidis-dioicae (MvSl) and M. silenes-dioicae (MvSd), from across Europe, on the basis of Illumina genome sequencing data and high-quality genome references. We observed presence-absence polymorphism for 186 autosomal genes (2% of all genes) in MvSl, and only 51 autosomal genes in MvSd. Distinct genes displayed presence-absence polymorphism in the two species. Genes displaying presence-absence polymorphism were frequently located in subtelomeric and centromeric regions and close to repetitive elements, and comparison with outgroups indicated that most were present in a single species, being recently acquired through duplications in multiple-gene families. Gene presence-absence polymorphism in MvSl showed a phylogeographic structure corresponding to clusters detected based on SNPs. In addition, gene absence alleles were rare within species and skewed toward low-frequency variants. These findings are consistent with a deleterious or neutral effect for most gene presence-absence polymorphism. Some of the observed gene loss and gain events may however be adaptive, as suggested by the putative functions of the corresponding encoded proteins (e.g., secreted proteins) or their localization within previously identified selective sweeps. The adaptive roles in plant and anther-smut fungi interactions of candidate genes however need to be experimentally tested in future studies.
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Affiliation(s)
- Fanny E Hartmann
- Department Génétique et Ecologie Evolutives, Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Ricardo C Rodríguez de la Vega
- Department Génétique et Ecologie Evolutives, Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Jean-Tristan Brandenburg
- Department Génétique et Ecologie Evolutives, Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Fantin Carpentier
- Department Génétique et Ecologie Evolutives, Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
| | - Tatiana Giraud
- Department Génétique et Ecologie Evolutives, Ecologie Systématique Evolution, Bâtiment 360, Univ. Paris-Sud, AgroParisTech, CNRS, Université Paris-Saclay, Orsay, France
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