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de la Rosa S, Schol CR, Ramos Peregrina Á, Winter DJ, Hilgers AM, Maeda K, Iida Y, Tarallo M, Jia R, Beenen HG, Rocafort M, de Wit PJGM, Bowen JK, Bradshaw RE, Joosten MHAJ, Bai Y, Mesarich CH. Sequential breakdown of the Cf-9 leaf mould resistance locus in tomato by Fulvia fulva. THE NEW PHYTOLOGIST 2024; 243:1522-1538. [PMID: 38922927 DOI: 10.1111/nph.19925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024]
Abstract
Leaf mould, caused by Fulvia fulva, is a devastating disease of tomato plants. In many commercial tomato cultivars, resistance to this disease is governed by the Cf-9 locus, which encodes five paralogous receptor-like proteins. Two of these proteins confer resistance: Cf-9C recognises the previously identified F. fulva effector Avr9 and provides resistance during all plant growth stages, while Cf-9B recognises the yet-unidentified F. fulva effector Avr9B and provides mature plant resistance only. In recent years, F. fulva strains have emerged that can overcome the Cf-9 locus, with Cf-9C circumvented through Avr9 deletion. To understand how Cf-9B is circumvented, we set out to identify Avr9B. Comparative genomics, transient expression assays and gene complementation experiments were used to identify Avr9B, while gene sequencing was used to assess Avr9B allelic variation across a world-wide strain collection. A strict correlation between Avr9 deletion and resistance-breaking mutations in Avr9B was observed in strains recently collected from Cf-9 cultivars, whereas Avr9 deletion but no mutations in Avr9B were observed in older strains. This research showcases how F. fulva has evolved to sequentially break down the Cf-9 locus and stresses the urgent need for commercial tomato cultivars that carry novel, stacked resistance genes active against this pathogen.
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Affiliation(s)
- Silvia de la Rosa
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, 4410, New Zealand
| | - Christiaan R Schol
- Plant Breeding, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Ángeles Ramos Peregrina
- Plant Breeding, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - David J Winter
- Bioinformatics Group, School of Food Technology and Natural Sciences, Massey University, Palmerston North, 4410, New Zealand
| | - Anne M Hilgers
- Plant Breeding, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Kazuya Maeda
- Laboratory of Plant Pathology, Faculty of Agriculture, Setsunan University, Hirakata, Osaka, 573-0101, Japan
| | - Yuichiro Iida
- Laboratory of Plant Pathology, Faculty of Agriculture, Setsunan University, Hirakata, Osaka, 573-0101, Japan
| | - Mariana Tarallo
- Laboratory of Molecular Plant Pathology, School of Food Technology and Natural Sciences, Massey University, Palmerston North, 4410, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, 4410, New Zealand
| | - Ruifang Jia
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Henriek G Beenen
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Mercedes Rocafort
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, 4410, New Zealand
| | - Pierre J G M de Wit
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Joanna K Bowen
- The New Zealand Institute for Plant and Food Research Ltd, Mount Albert Research Centre, Auckland, 1025, New Zealand
| | - Rosie E Bradshaw
- Laboratory of Molecular Plant Pathology, School of Food Technology and Natural Sciences, Massey University, Palmerston North, 4410, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, 4410, New Zealand
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Yuling Bai
- Plant Breeding, Wageningen University & Research, Wageningen, 6708 PB, the Netherlands
| | - Carl H Mesarich
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, 4410, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, 4410, New Zealand
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2
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Zaccaron AZ, Stergiopoulos I. Analysis of five near-complete genome assemblies of the tomato pathogen Cladosporium fulvum uncovers additional accessory chromosomes and structural variations induced by transposable elements effecting the loss of avirulence genes. BMC Biol 2024; 22:25. [PMID: 38281938 PMCID: PMC10823647 DOI: 10.1186/s12915-024-01818-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/04/2024] [Indexed: 01/30/2024] Open
Abstract
BACKGROUND Fungal plant pathogens have dynamic genomes that allow them to rapidly adapt to adverse conditions and overcome host resistance. One way by which this dynamic genome plasticity is expressed is through effector gene loss, which enables plant pathogens to overcome recognition by cognate resistance genes in the host. However, the exact nature of these loses remains elusive in many fungi. This includes the tomato pathogen Cladosporium fulvum, which is the first fungal plant pathogen from which avirulence (Avr) genes were ever cloned and in which loss of Avr genes is often reported as a means of overcoming recognition by cognate tomato Cf resistance genes. A recent near-complete reference genome assembly of C. fulvum isolate Race 5 revealed a compartmentalized genome architecture and the presence of an accessory chromosome, thereby creating a basis for studying genome plasticity in fungal plant pathogens and its impact on avirulence genes. RESULTS Here, we obtained near-complete genome assemblies of four additional C. fulvum isolates. The genome assemblies had similar sizes (66.96 to 67.78 Mb), number of predicted genes (14,895 to 14,981), and estimated completeness (98.8 to 98.9%). Comparative analysis that included the genome of isolate Race 5 revealed high levels of synteny and colinearity, which extended to the density and distribution of repetitive elements and of repeat-induced point (RIP) mutations across homologous chromosomes. Nonetheless, structural variations, likely mediated by transposable elements and effecting the deletion of the avirulence genes Avr4E, Avr5, and Avr9, were also identified. The isolates further shared a core set of 13 chromosomes, but two accessory chromosomes were identified as well. Accessory chromosomes were significantly smaller in size, and one carried pseudogenized copies of two effector genes. Whole-genome alignments further revealed genomic islands of near-zero nucleotide diversity interspersed with islands of high nucleotide diversity that co-localized with repeat-rich regions. These regions were likely generated by RIP, which generally asymmetrically affected the genome of C. fulvum. CONCLUSIONS Our results reveal new evolutionary aspects of the C. fulvum genome and provide new insights on the importance of genomic structural variations in overcoming host resistance in fungal plant pathogens.
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Affiliation(s)
- Alex Z Zaccaron
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616-8751, USA
| | - Ioannis Stergiopoulos
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616-8751, USA.
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3
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Mesarich CH, Barnes I, Bradley EL, de la Rosa S, de Wit PJGM, Guo Y, Griffiths SA, Hamelin RC, Joosten MHAJ, Lu M, McCarthy HM, Schol CR, Stergiopoulos I, Tarallo M, Zaccaron AZ, Bradshaw RE. Beyond the genomes of Fulvia fulva (syn. Cladosporium fulvum) and Dothistroma septosporum: New insights into how these fungal pathogens interact with their host plants. MOLECULAR PLANT PATHOLOGY 2023; 24:474-494. [PMID: 36790136 PMCID: PMC10098069 DOI: 10.1111/mpp.13309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 05/03/2023]
Abstract
Fulvia fulva and Dothistroma septosporum are closely related apoplastic pathogens with similar lifestyles but different hosts: F. fulva is a pathogen of tomato, whilst D. septosporum is a pathogen of pine trees. In 2012, the first genome sequences of these pathogens were published, with F. fulva and D. septosporum having highly fragmented and near-complete assemblies, respectively. Since then, significant advances have been made in unravelling their genome architectures. For instance, the genome of F. fulva has now been assembled into 14 chromosomes, 13 of which have synteny with the 14 chromosomes of D. septosporum, suggesting these pathogens are even more closely related than originally thought. Considerable advances have also been made in the identification and functional characterization of virulence factors (e.g., effector proteins and secondary metabolites) from these pathogens, thereby providing new insights into how they promote host colonization or activate plant defence responses. For example, it has now been established that effector proteins from both F. fulva and D. septosporum interact with cell-surface immune receptors and co-receptors to activate the plant immune system. Progress has also been made in understanding how F. fulva and D. septosporum have evolved with their host plants, whilst intensive research into pandemics of Dothistroma needle blight in the Northern Hemisphere has shed light on the origins, migration, and genetic diversity of the global D. septosporum population. In this review, we specifically summarize advances made in our understanding of the F. fulva-tomato and D. septosporum-pine pathosystems over the last 10 years.
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Affiliation(s)
- Carl H Mesarich
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
| | - Irene Barnes
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Ellie L Bradley
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Silvia de la Rosa
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Pierre J G M de Wit
- Laboratory of Phytopathology, Wageningen University, Wageningen, Netherlands
| | - Yanan Guo
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | | | - Richard C Hamelin
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec City, Québec, Canada
| | | | - Mengmeng Lu
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Hannah M McCarthy
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Christiaan R Schol
- Laboratory of Phytopathology, Wageningen University, Wageningen, Netherlands
- Plant Breeding, Wageningen University & Research, Wageningen, Netherlands
| | - Ioannis Stergiopoulos
- Department of Plant Pathology, University of California Davis, Davis, California, USA
| | - Mariana Tarallo
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Alex Z Zaccaron
- Department of Plant Pathology, University of California Davis, Davis, California, USA
| | - Rosie E Bradshaw
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
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Yu C, Qi J, Han H, Wang P, Liu C. Progress in pathogenesis research of Ustilago maydis, and the metabolites involved along with their biosynthesis. MOLECULAR PLANT PATHOLOGY 2023; 24:495-509. [PMID: 36808861 PMCID: PMC10098057 DOI: 10.1111/mpp.13307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/26/2022] [Accepted: 01/13/2023] [Indexed: 05/03/2023]
Abstract
Ustilago maydis is a pathogenic fungus that causes corn smut. Because of its easy cultivation and genetic transformation, U. maydis has become an important model organism for plant-pathogenic basidiomycetes. U. maydis is able to infect maize by producing effectors and secreted proteins as well as surfactant-like metabolites. In addition, the production of melanin and iron carriers is also associated with its pathogenicity. Here, advances in our understanding of the pathogenicity of U. maydis, the metabolites involved in the pathogenic process, and the biosynthesis of these metabolites, are reviewed and discussed. This summary will provide new insights into the pathogenicity of U. maydis and the functions of associated metabolites, as well as new clues for deciphering the biosynthesis of metabolites.
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Affiliation(s)
- Chunyan Yu
- Key Laboratory for Enzyme and Enzyme‐Like Material Engineering of Heilongjiang, College of Life ScienceNortheast Forestry UniversityHarbinChina
| | - Jianzhao Qi
- Key Laboratory for Enzyme and Enzyme‐Like Material Engineering of Heilongjiang, College of Life ScienceNortheast Forestry UniversityHarbinChina
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & PharmacyNorthwest A&F UniversityYanglingChina
| | - Haiyan Han
- Key Laboratory for Enzyme and Enzyme‐Like Material Engineering of Heilongjiang, College of Life ScienceNortheast Forestry UniversityHarbinChina
| | - Pengchao Wang
- Key Laboratory for Enzyme and Enzyme‐Like Material Engineering of Heilongjiang, College of Life ScienceNortheast Forestry UniversityHarbinChina
| | - Chengwei Liu
- Key Laboratory for Enzyme and Enzyme‐Like Material Engineering of Heilongjiang, College of Life ScienceNortheast Forestry UniversityHarbinChina
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5
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Snelders NC, Boshoven JC, Song Y, Schmitz N, Fiorin GL, Rovenich H, van den Berg GCM, Torres DE, Petti GC, Prockl Z, Faino L, Seidl MF, Thomma BPHJ. A highly polymorphic effector protein promotes fungal virulence through suppression of plant-associated Actinobacteria. THE NEW PHYTOLOGIST 2023; 237:944-958. [PMID: 36300791 DOI: 10.1111/nph.18576] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
Plant pathogens secrete effector proteins to support host colonization through a wide range of molecular mechanisms, while plant immune systems evolved receptors to recognize effectors or their activities to mount immune responses to halt pathogens. Importantly, plants do not act as single organisms, but rather as holobionts that actively shape their microbiota as a determinant of health. The soil-borne fungal pathogen Verticillium dahliae was recently demonstrated to exploit the VdAve1 effector to manipulate the host microbiota to promote vascular wilt disease in the absence of the corresponding immune receptor Ve1. We identify a multiallelic V. dahliae gene displaying c. 65% sequence similarity to VdAve1, named VdAve1-like (VdAve1L), which shows extreme sequence variation, including alleles that encode dysfunctional proteins, indicative of selection pressure to overcome host recognition. We show that the orphan cell surface receptor Ve2, encoded at the Ve locus, does not recognize VdAve1L. Additionally, we demonstrate that the full-length variant VdAve1L2 possesses antimicrobial activity, like VdAve1, yet with a divergent activity spectrum, that is exploited by V. dahliae to mediate tomato colonization through the direct suppression of antagonistic Actinobacteria in the host microbiota. Our findings open up strategies for more targeted biocontrol against microbial plant pathogens.
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Affiliation(s)
- Nick C Snelders
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
- Theoretical Biology and Bioinformatics Group, Department of Biology, University of Utrecht, 3584CH, Utrecht, the Netherlands
| | - Jordi C Boshoven
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
| | - Yin Song
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Natalie Schmitz
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Gabriel L Fiorin
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
| | - Hanna Rovenich
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Grardy C M van den Berg
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
| | - David E Torres
- Theoretical Biology and Bioinformatics Group, Department of Biology, University of Utrecht, 3584CH, Utrecht, the Netherlands
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
| | - Gabriella C Petti
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Zoe Prockl
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Luigi Faino
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
- Department of Ambiental Biology, Sapienza University of Rome, 00185, Rome, Italy
| | - Michael F Seidl
- Theoretical Biology and Bioinformatics Group, Department of Biology, University of Utrecht, 3584CH, Utrecht, the Netherlands
| | - Bart P H J Thomma
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB, Wageningen, the Netherlands
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6
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Saubin M, Louet C, Bousset L, Fabre F, Frey P, Fudal I, Grognard F, Hamelin F, Mailleret L, Stoeckel S, Touzeau S, Petre B, Halkett F. Improving sustainable crop protection using population genetics concepts. Mol Ecol 2022; 32:2461-2471. [PMID: 35906846 DOI: 10.1111/mec.16634] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 10/16/2022]
Abstract
Growing genetically resistant plants allows pathogen populations to be controlled and reduces the use of pesticides. However, pathogens can quickly overcome such resistance. In this context, how can we achieve sustainable crop protection? This crucial question has remained largely unanswered despite decades of intense debate and research effort. In this study, we used a bibliographic analysis to show that the research field of resistance durability has evolved into three subfields: (i) 'plant breeding' (generating new genetic material), (ii) 'molecular interactions' (exploring the molecular dialogue governing plant-pathogen interactions) and (iii) 'epidemiology and evolution' (explaining and forecasting of pathogen population dynamics resulting from selection pressure(s) exerted by resistant plants). We argue that this triple split of the field impedes integrated research progress and ultimately compromises the sustainable management of genetic resistance. After identifying a gap among the three subfields, we argue that the theoretical framework of population genetics could bridge this gap. Indeed, population genetics formally explains the evolution of all heritable traits, and allows genetic changes to be tracked along with variation in population dynamics. This provides an integrated view of pathogen adaptation, in particular via evolutionary-epidemiological feedbacks. In this Opinion Note, we detail examples illustrating how such a framework can better inform best practices for developing and managing genetically resistant cultivars.
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Affiliation(s)
| | - Clémentine Louet
- Université de Lorraine, INRAE, IAM, Nancy, France.,Université Paris Saclay, INRAE, BIOGER, Thiverval-Grignon, France
| | - Lydia Bousset
- INRAE, Agrocampus Ouest, Université de Rennes, IGEPP, Le Rheu, France
| | - Frédéric Fabre
- INRAE, Bordeaux Sciences Agro, SAVE, F-33882 Villenave d'Ornon, France
| | - Pascal Frey
- Université de Lorraine, INRAE, IAM, Nancy, France
| | - Isabelle Fudal
- Université Paris Saclay, INRAE, BIOGER, Thiverval-Grignon, France
| | - Frédéric Grognard
- Université Côte d'Azur, Inria, INRAE, CNRS, Sorbonne Université, Biocore team, Sophia Antipolis, France
| | - Frédéric Hamelin
- INRAE, Agrocampus Ouest, Université de Rennes, IGEPP, Le Rheu, France
| | - Ludovic Mailleret
- Université Côte d'Azur, Inria, INRAE, CNRS, Sorbonne Université, Biocore team, Sophia Antipolis, France.,Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | - Solenn Stoeckel
- INRAE, Agrocampus Ouest, Université de Rennes, IGEPP, Le Rheu, France
| | - Suzanne Touzeau
- Université Côte d'Azur, Inria, INRAE, CNRS, Sorbonne Université, Biocore team, Sophia Antipolis, France
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Li X, Yang S, Zhang M, Yang Y, Peng L. Identification of Pathogenicity-Related Effector Proteins and the Role of Piwsc1 in the Virulence of Penicillium italicum on Citrus Fruits. J Fungi (Basel) 2022; 8:jof8060646. [PMID: 35736129 PMCID: PMC9224591 DOI: 10.3390/jof8060646] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 06/12/2022] [Accepted: 06/16/2022] [Indexed: 02/01/2023] Open
Abstract
Blue mold caused by Penicillium italicum is one of the two major postharvest diseases of citrus fruits. The interactions of pathogens with their hosts are complicated, and virulence factors that mediate pathogenicity have not yet been identified. In present study, a prediction pipeline approach based on bioinformatics and transcriptomic data is designed to determine the effector proteins of P. italicum. Three hundred and seventy-five secreted proteins of P. italicum were identified, many of which (29.07%) were enzymes for carbohydrate utilization. Twenty-nine candidates were further analyzed and the expression patterns of 12 randomly selected candidate effector genes were monitored during the early stages of growth on PDA and infection of Navel oranges for validation. Functional analysis of a cell wall integrity-related gene Piwsc1, a core candidate, was performed by gene knockout. The deletion of Piwsc1 resulted in reduced virulence on citrus fruits, as presented by an approximate 57% reduction in the diameter of lesions. In addition, the mycelial growth rate, spore germination rate, and sporulation of ΔPiwsc1 decreased. The findings provide us with new insights to understand the pathogenesis of P. italicum and develop an effective and sustainable control method for blue mold.
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Sudermann MA, McGilp L, Vogel G, Regnier M, Jaramillo AR, Smart CD. The Diversity of Passalora fulva Isolates Collected from Tomato Plants in U.S. High Tunnels. PHYTOPATHOLOGY 2022; 112:1350-1360. [PMID: 35021861 DOI: 10.1094/phyto-06-21-0244-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
High tunnels extend the growing season of high value crops, including tomatoes, but the environmental conditions within high tunnels favor the spread of the tomato leaf mold pathogen, Passalora fulva (syn. Cladosporium fulvum). Tomato leaf mold results in defoliation, and if severe, losses in yield. Despite substantial research, little is known regarding the genetic structure and diversity of populations of P. fulva associated with high tunnel tomato production in the United States. From 2016 to 2019, a total of 50 P. fulva isolates were collected from tomato leaf samples in high tunnels in the Northeast and Minnesota. Other Cladosporium species were also isolated from the leaf surfaces. Koch's postulates were conducted to confirm that P. fulva was the cause of the disease symptoms observed. Race determination experiments revealed that the isolates belonged to either race 0 (six isolates) or race 2 (44 isolates). Polymorphisms were identified within four previously characterized effector genes: Avr2, Avr4, Avr4e, and Avr9. The largest number of polymorphisms were observed for Avr2. Both mating type genes, MAT1-1-1 and MAT1-2-1, were present in the isolate collection. For further insights into the pathogen diversity, the 50 isolates were genotyped at 7,514 single-nucleotide polymorphism loci using genotyping-by-sequencing. Differentiation by region but not by year was observed. Within the collection of 50 isolates, there were 18 distinct genotypes. Information regarding P. fulva population diversity will enable better management recommendations for growers, as high tunnel production of tomatoes expands.
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Affiliation(s)
- Martha A Sudermann
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, U.S.A
| | - Lillian McGilp
- Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, U.S.A
| | - Gregory Vogel
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, U.S.A
- Plant Breeding and Genetics Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Melissa Regnier
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, U.S.A
- Laboratory of Mycology and Phytopathology, Department of Biological Sciences, Universidad de los Andes, Bogotá 111711, Colombia
| | - Alejandra Rodríguez Jaramillo
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, U.S.A
| | - Christine D Smart
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Geneva, NY 14456, U.S.A
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9
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Zaccaron AZ, Chen LH, Samaras A, Stergiopoulos I. A chromosome-scale genome assembly of the tomato pathogen Cladosporium fulvum reveals a compartmentalized genome architecture and the presence of a dispensable chromosome. Microb Genom 2022; 8:000819. [PMID: 35471194 PMCID: PMC9453070 DOI: 10.1099/mgen.0.000819] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 03/29/2022] [Indexed: 01/25/2023] Open
Abstract
Cladosporium fulvum is a fungal pathogen that causes leaf mould of tomato. The reference genome of this pathogen was released in 2012 but its high repetitive DNA content prevented a contiguous assembly and further prohibited the analysis of its genome architecture. In this study, we combined third generation sequencing technology with the Hi-C chromatin conformation capture technique, to produce a high-quality and near complete genome assembly and gene annotation of a Race 5 isolate of C. fulvum. The resulting genome assembly contained 67.17 Mb organized into 14 chromosomes (Chr1-to-Chr14), all of which were assembled telomere-to-telomere. The smallest of the chromosomes, Chr14, is only 460 kb in size and contains 25 genes that all encode hypothetical proteins. Notably, PCR assays revealed that Chr14 was absent in 19 out of 24 isolates of a world-wide collection of C. fulvum, indicating that Chr14 is dispensable. Thus, C. fulvum is currently the second species of Capnodiales shown to harbour dispensable chromosomes. The genome of C. fulvum Race 5 is 49.7 % repetitive and contains 14 690 predicted genes with an estimated completeness of 98.9%, currently one of the highest among the Capnodiales. Genome structure analysis revealed a compartmentalized architecture composed of gene-dense and repeat-poor regions interspersed with gene-sparse and repeat-rich regions. Nearly 39.2 % of the C. fulvum Race 5 genome is affected by Repeat-Induced Point (RIP) mutations and evidence of RIP leakage toward non-repetitive regions was observed in all chromosomes, indicating the RIP plays an important role in the evolution of this pathogen. Finally, 345 genes encoding candidate effectors were identified in C. fulvum Race 5, with a significant enrichment of their location in gene-sparse regions, in accordance with the 'two-speed genome' model of evolution. Overall, the new reference genome of C. fulvum presents several notable features and is a valuable resource for studies in plant pathogens.
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Affiliation(s)
- Alex Z. Zaccaron
- Department of Plant Pathology, University of California Davis, Davis, USA
| | - Li-Hung Chen
- Department of Plant Pathology, University of California Davis, Davis, USA
- Present address: Department of Plant Pathology, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Anastasios Samaras
- Department of Plant Pathology, University of California Davis, Davis, USA
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10
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Bentham AR, Petit-Houdenot Y, Win J, Chuma I, Terauchi R, Banfield MJ, Kamoun S, Langner T. A single amino acid polymorphism in a conserved effector of the multihost blast fungus pathogen expands host-target binding spectrum. PLoS Pathog 2021; 17:e1009957. [PMID: 34758051 PMCID: PMC8608293 DOI: 10.1371/journal.ppat.1009957] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 11/22/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
Accelerated gene evolution is a hallmark of pathogen adaptation and specialization following host-jumps. However, the molecular processes associated with adaptive evolution between host-specific lineages of a multihost plant pathogen remain poorly understood. In the blast fungus Magnaporthe oryzae (Syn. Pyricularia oryzae), host specialization on different grass hosts is generally associated with dynamic patterns of gain and loss of virulence effector genes that tend to define the distinct genetic lineages of this pathogen. Here, we unravelled the biochemical and structural basis of adaptive evolution of APikL2, an exceptionally conserved paralog of the well-studied rice-lineage specific effector AVR-Pik. Whereas AVR-Pik and other members of the six-gene AVR-Pik family show specific patterns of presence/absence polymorphisms between grass-specific lineages of M. oryzae, APikL2 stands out by being ubiquitously present in all blast fungus lineages from 13 different host species. Using biochemical, biophysical and structural biology methods, we show that a single aspartate to asparagine polymorphism expands the binding spectrum of APikL2 to host proteins of the heavy-metal associated (HMA) domain family. This mutation maps to one of the APikL2-HMA binding interfaces and contributes to an altered hydrogen-bonding network. By combining phylogenetic ancestral reconstruction with an analysis of the structural consequences of allelic diversification, we revealed a common mechanism of effector specialization in the AVR-Pik/APikL2 family that involves two major HMA-binding interfaces. Together, our findings provide a detailed molecular evolution and structural biology framework for diversification and adaptation of a fungal pathogen effector family following host-jumps.
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Affiliation(s)
- Adam R. Bentham
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Yohann Petit-Houdenot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, France
| | - Joe Win
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Izumi Chuma
- Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Ryohei Terauchi
- Kyoto University, Kyoto, Japan
- Iwate Biotechnology Research Center, Kitakami, Japan
| | - Mark J. Banfield
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
| | - Thorsten Langner
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, United Kingdom
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11
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Shen LL, Waheed A, Wang YP, Nkurikiyimfura O, Wang ZH, Yang LN, Zhan J. Multiple Mechanisms Drive the Evolutionary Adaptation of Phytophthora infestans Effector Avr1 to Host Resistance. J Fungi (Basel) 2021; 7:jof7100789. [PMID: 34682211 PMCID: PMC8538934 DOI: 10.3390/jof7100789] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/08/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
Effectors, a group of small proteins secreted by pathogens, play a central role in antagonistic interactions between plant hosts and pathogens. The evolution of effector genes threatens plant disease management and sustainable food production, but population genetic analyses to understand evolutionary mechanisms of effector genes are limited compared to molecular and functional studies. Here we investigated the evolution of the Avr1 effector gene from 111 Phytophthora infestans isolates collected from six areas covering three potato cropping regions in China using a population genetic approach. High genetic variation of the effector gene resulted from diverse mechanisms including base substitution, pre-termination, intragenic recombination and diversifying selection. Nearly 80% of the 111 sequences had a point mutation in the 512th nucleotide (T512G), which generated a pre-termination stop codon truncating 38 amino acids in the C-terminal, suggesting that the C-terminal may not be essential to ecological and biological functions of P. infestans. A significant correlation between the frequency of Avr1 sequences with the pre-termination and annual mean temperature in the collection sites suggests that thermal heterogeneity might be one of contributors to the diversifying selection, although biological and biochemical mechanisms of the likely thermal adaptation are not known currently. Our results highlight the risk of rapid adaptation of P. infestans and possibly other pathogens as well to host resistance, and the application of eco-evolutionary principles is necessary for sustainable disease management in agricultural ecosystems.
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Affiliation(s)
- Lin-Lin Shen
- Key Lab for Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education, Fuzhou 350002, China; (L.-L.S.); (A.W.); (O.N.)
| | - Abdul Waheed
- Key Lab for Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education, Fuzhou 350002, China; (L.-L.S.); (A.W.); (O.N.)
| | - Yan-Ping Wang
- College of Chemistry and Life Sciences, Sichuan Provincial Key Laboratory for Development and Utilization of Characteristic Horticultural Biological Resources, Chengdu Normal University, Chengdu 611130, China;
| | - Oswald Nkurikiyimfura
- Key Lab for Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education, Fuzhou 350002, China; (L.-L.S.); (A.W.); (O.N.)
| | - Zong-Hua Wang
- Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
- Institute of Oceanography, Minjiang University, Fuzhou 350108, China
| | - Li-Na Yang
- Key Lab for Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education, Fuzhou 350002, China; (L.-L.S.); (A.W.); (O.N.)
- Institute of Oceanography, Minjiang University, Fuzhou 350108, China
- Correspondence: (L.-N.Y.); (J.Z.); Tel.: +86-177-2080-5328 (L.-N.Y.); +46-18-673-639 (J.Z.)
| | - Jiasui Zhan
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Correspondence: (L.-N.Y.); (J.Z.); Tel.: +86-177-2080-5328 (L.-N.Y.); +46-18-673-639 (J.Z.)
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12
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Soyer JL, Clairet C, Gay EJ, Lapalu N, Rouxel T, Stukenbrock EH, Fudal I. Genome-wide mapping of histone modifications during axenic growth in two species of Leptosphaeria maculans showing contrasting genomic organization. Chromosome Res 2021; 29:219-236. [PMID: 34018080 PMCID: PMC8159818 DOI: 10.1007/s10577-021-09658-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/16/2021] [Accepted: 03/03/2021] [Indexed: 12/25/2022]
Abstract
Leptosphaeria maculans 'brassicae' (Lmb) and Leptosphaeria maculans 'lepidii' (Lml) are closely related phytopathogenic species that exhibit a large macrosynteny but contrasting genome structure. Lmb has more than 30% of repeats clustered in large repeat-rich regions, while the Lml genome has only a small amount of evenly distributed repeats. Repeat-rich regions of Lmb are enriched in effector genes, expressed during plant infection. The distinct genome structures of Lmb and Lml provide an excellent model for comparing the organization of pathogenicity genes in relation to the chromatin landscape in two closely related phytopathogenic fungi. Here, we performed chromatin immunoprecipitation (ChIP) during axenic culture, targeting histone modifications typical for heterochromatin or euchromatin, combined with transcriptomic analysis to analyze the influence of chromatin organization on gene expression. In both species, we found that facultative heterochromatin is enriched with genes lacking functional annotation, including numerous effector and species-specific genes. Notably, orthologous genes located in H3K27me3 domains are enriched with effector genes. Compared to other fungal species, including Lml, Lmb is distinct in having large H3K9me3 domains associated with repeat-rich regions that contain numerous species-specific effector genes. Discovery of these two distinctive heterochromatin landscapes now raises questions about their involvement in the regulation of pathogenicity, the dynamics of these domains during plant infection and the selective advantage to the fungus to host effector genes in H3K9me3 or H3K27me3 domains.
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Affiliation(s)
- Jessica L Soyer
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France.
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.
- Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany.
| | - Colin Clairet
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Elise J Gay
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Nicolas Lapalu
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Thierry Rouxel
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
| | - Eva H Stukenbrock
- Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
- Christian-Albrechts University of Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Isabelle Fudal
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, 78850, Thiverval-Grignon, France
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13
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Chavarro‐Carrero EA, Vermeulen JP, E. Torres D, Usami T, Schouten HJ, Bai Y, Seidl MF, Thomma BPHJ. Comparative genomics reveals the in planta-secreted Verticillium dahliae Av2 effector protein recognized in tomato plants that carry the V2 resistance locus. Environ Microbiol 2021; 23:1941-1958. [PMID: 33078534 PMCID: PMC8246953 DOI: 10.1111/1462-2920.15288] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 12/12/2022]
Abstract
Plant pathogens secrete effector molecules during host invasion to promote colonization. However, some of these effectors become recognized by host receptors to mount a defence response and establish immunity. Recently, a novel resistance was identified in wild tomato, mediated by the single dominant V2 locus, to control strains of the soil-borne vascular wilt fungus Verticillium dahliae that belong to race 2. With comparative genomics of race 2 strains and resistance-breaking race 3 strains, we identified the avirulence effector that activates V2 resistance, termed Av2. We identified 277 kb of race 2-specific sequence comprising only two genes encoding predicted secreted proteins that are expressed during tomato colonization. Subsequent functional analysis based on genetic complementation into race 3 isolates and targeted deletion from the race 1 isolate JR2 and race 2 isolate TO22 confirmed that one of the two candidates encodes the avirulence effector Av2 that is recognized in V2 tomato plants. Two Av2 allelic variants were identified that encode Av2 variants that differ by a single acid. Thus far, a role in virulence could not be demonstrated for either of the two variants.
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Affiliation(s)
| | - Jasper P. Vermeulen
- Laboratory of PhytopathologyWageningen University and ResearchWageningen6708 PBThe Netherlands
- Laboratory of Plant BreedingWageningen University and ResearchWageningen6708 PBThe Netherlands
| | - David E. Torres
- Laboratory of PhytopathologyWageningen University and ResearchWageningen6708 PBThe Netherlands
- Theoretical Biology and Bioinformatics Group, Department of BiologyUtrecht UniversityUtrechtThe Netherlands
| | - Toshiyuki Usami
- Graduate School of HorticultureChiba UniversityMatsudo, Chiba271‐8510Japan
| | - Henk J. Schouten
- Laboratory of Plant BreedingWageningen University and ResearchWageningen6708 PBThe Netherlands
| | - Yuling Bai
- Laboratory of Plant BreedingWageningen University and ResearchWageningen6708 PBThe Netherlands
| | - Michael F. Seidl
- Laboratory of PhytopathologyWageningen University and ResearchWageningen6708 PBThe Netherlands
- Theoretical Biology and Bioinformatics Group, Department of BiologyUtrecht UniversityUtrechtThe Netherlands
| | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen University and ResearchWageningen6708 PBThe Netherlands
- Cluster of Excellence on Plant Sciences (CEPLAS)University of Cologne, Botanical InstituteCologneGermany
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14
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Kourelis J, Malik S, Mattinson O, Krauter S, Kahlon PS, Paulus JK, van der Hoorn RAL. Evolution of a guarded decoy protease and its receptor in solanaceous plants. Nat Commun 2020; 11:4393. [PMID: 32879321 PMCID: PMC7468133 DOI: 10.1038/s41467-020-18069-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/03/2020] [Indexed: 12/26/2022] Open
Abstract
Rcr3 is a secreted protease of tomato that is targeted by fungal effector Avr2, a secreted protease inhibitor of the fungal pathogen Cladosporium fulvum. The Avr2-Rcr3 complex is recognized by receptor-like protein Cf-2, triggering hypersensitive cell death (HR) and disease resistance. Avr2 also targets Rcr3 paralog Pip1, which is not required for Avr2 recognition but contributes to basal resistance. Thus, Rcr3 acts as a guarded decoy in this interaction, trapping the fungus into a recognition event. Here we show that Rcr3 evolved > 50 million years ago (Mya), whereas Cf-2 evolved <6Mya by co-opting the pre-existing Rcr3 in the Solanum genus. Ancient Rcr3 homologs present in tomato, potato, eggplants, pepper, petunia and tobacco can be inhibited by Avr2 with the exception of tobacco Rcr3. Four variant residues in Rcr3 promote Avr2 inhibition, but the Rcr3 that co-evolved with Cf-2 lacks three of these residues, indicating that the Rcr3 co-receptor is suboptimal for Avr2 binding. Pepper Rcr3 triggers HR with Cf-2 and Avr2 when engineered for enhanced inhibition by Avr2. Nicotiana benthamiana (Nb) is a natural null mutant carrying Rcr3 and Pip1 alleles with deleterious frame-shift mutations. Resurrected NbRcr3 and NbPip1 alleles were active proteases and further NbRcr3 engineering facilitated Avr2 inhibition, uncoupled from HR signalling. The evolution of a receptor co-opting a conserved pathogen target contrasts with other indirect pathogen recognition mechanisms.
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Affiliation(s)
- Jiorgos Kourelis
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Shivani Malik
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Oliver Mattinson
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Sonja Krauter
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Parvinderdeep S Kahlon
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Judith K Paulus
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK
| | - Renier A L van der Hoorn
- Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB, Oxford, UK.
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15
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Morales JG, Gaviria AE, Gilchrist E. Allelic Variation and Selection in Effector Genes of Phytophthora infestans (Mont.) de Bary. Pathogens 2020; 9:pathogens9070551. [PMID: 32659973 PMCID: PMC7400436 DOI: 10.3390/pathogens9070551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 12/12/2022] Open
Abstract
Phytophthora infestans is a devastating plant pathogen in several crops such as potato (Solanum tuberosum), tomato (Solanum lycopersicum) and Andean fruits such as tree tomato (Solanum betaceum), lulo (Solanum quitoense), uchuva (Physalis peruviana) and wild species in the genus Solanum sp. Despite intense research performed around the world, P. infestans populations from Colombia, South America, are poorly understood. Of particular importance is knowledge about pathogen effector proteins, which are responsible for virulence. The present work was performed with the objective to analyze gene sequences coding for effector proteins of P. infestans from isolates collected from different hosts and geographical regions. Several genetic parameters, phylogenetic analyses and neutrality tests for non-synonymous and synonymous substitutions were calculated. Non-synonymous substitutions were identified for all genes that exhibited polymorphisms at the DNA level. Significant negative selection values were found for two genes (PITG_08994 and PITG_12737) suggesting active coevolution with the corresponding host resistance proteins. Implications for pathogen virulence mechanisms and disease management are discussed.
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Affiliation(s)
- Juan G. Morales
- Group and Laboratory of Fitotecnia Tropical, Departamento de Ciencias Agronómicas, Facultad de Ciencias Agrarias, Universidad Nacional de Colombia sede Medellín, Medellín, 050034 Antioquia, Colombia; (A.E.G.); (E.G.)
- Correspondence: ; Tel.: +0057-4-4309088
| | - Astrid E. Gaviria
- Group and Laboratory of Fitotecnia Tropical, Departamento de Ciencias Agronómicas, Facultad de Ciencias Agrarias, Universidad Nacional de Colombia sede Medellín, Medellín, 050034 Antioquia, Colombia; (A.E.G.); (E.G.)
| | - Elizabeth Gilchrist
- Group and Laboratory of Fitotecnia Tropical, Departamento de Ciencias Agronómicas, Facultad de Ciencias Agrarias, Universidad Nacional de Colombia sede Medellín, Medellín, 050034 Antioquia, Colombia; (A.E.G.); (E.G.)
- Universidad EAFIT, 050034 Medellín, Colombia
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16
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Lin X, Wang S, de Rond L, Bertolin N, Wouters RHM, Wouters D, Domazakis E, Bitew MK, Win J, Dong S, Visser RGF, Birch P, Kamoun S, Vleeshouwers VGAA. Divergent Evolution of PcF/SCR74 Effectors in Oomycetes Is Associated with Distinct Recognition Patterns in Solanaceous Plants. mBio 2020; 11:e00947-20. [PMID: 32605983 PMCID: PMC7327169 DOI: 10.1128/mbio.00947-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/02/2020] [Indexed: 01/03/2023] Open
Abstract
Plants deploy cell surface receptors known as pattern-recognition receptors (PRRs) that recognize non-self molecules from pathogens and microbes to defend against invaders. PRRs typically recognize microbe-associated molecular patterns (MAMPs) that are usually widely conserved, some even across kingdoms. Here, we report an oomycete-specific family of small secreted cysteine-rich (SCR) proteins that displays divergent patterns of sequence variation in the Irish potato famine pathogen Phytophthora infestans A subclass that includes the conserved effector PcF from Phytophthora cactorum activates immunity in a wide range of plant species. In contrast, the more diverse SCR74 subclass is specific to P. infestans and tends to trigger immune responses only in a limited number of wild potato genotypes. The SCR74 response was recently mapped to a G-type lectin receptor kinase (G-LecRK) locus in the wild potato Solanum microdontum subsp. gigantophyllum. The G-LecRK locus displays a high diversity in Solanum host species compared to other solanaceous plants. We propose that the diversification of the SCR74 proteins in P. infestans is driven by a fast coevolutionary arms race with cell surface immune receptors in wild potato, which contrasts the presumed slower dynamics between conserved apoplastic effectors and PRRs. Understanding the molecular determinants of plant immune responses to these divergent molecular patterns in oomycetes is expected to contribute to deploying multiple layers of disease resistance in crop plants.IMPORTANCE Immune receptors at the plant cell surface can recognize invading microbes. The perceived microbial molecules are typically widely conserved and therefore the matching surface receptors can detect a broad spectrum of pathogens. Here we describe a family of Phytophthora small extracellular proteins that consists of conserved subfamilies that are widely recognized by solanaceous plants. Remarkably, one subclass of SCR74 proteins is highly diverse, restricted to the late blight pathogen Phytophthora infestans and is specifically detected in wild potato plants. The diversification of this subfamily exhibits signatures of a coevolutionary arms race with surface receptors in potato. Insights into the molecular interaction between these potato-specific receptors and the recognized Phytophthora proteins are expected to contribute to disease resistance breeding in potato.
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Affiliation(s)
- Xiao Lin
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Shumei Wang
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
| | - Laura de Rond
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Nicoletta Bertolin
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Roland H M Wouters
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Doret Wouters
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Emmanouil Domazakis
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Mulusew Kassa Bitew
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Joe Win
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Suomeng Dong
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
| | - Richard G F Visser
- Wageningen UR Plant Breeding, Wageningen University and Research, Wageningen, The Netherlands
| | - Paul Birch
- Cell and Molecular Sciences, The James Hutton Institute, Dundee, United Kingdom
- School of Life Sciences, Division of Plant Sciences, University of Dundee at the James Hutton Institute, Dundee, United Kingdom
| | - Sophien Kamoun
- The Sainsbury Laboratory, University of East Anglia, Norwich, United Kingdom
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17
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Iakovidis M, Soumpourou E, Anderson E, Etherington G, Yourstone S, Thomas C. Genes Encoding Recognition of the Cladosporium fulvum Effector Protein Ecp5 Are Encoded at Several Loci in the Tomato Genome. G3 (BETHESDA, MD.) 2020; 10:1753-1763. [PMID: 32209596 PMCID: PMC7202015 DOI: 10.1534/g3.120.401119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 03/12/2020] [Indexed: 12/12/2022]
Abstract
The molecular interactions between tomato and Cladosporium fulvum have been an important model for molecular plant pathology. Complex genetic loci on tomato chromosomes 1 and 6 harbor genes for resistance to Cladosporium fulvum, encoding receptor like-proteins that perceive distinct Cladosporium fulvum effectors and trigger plant defenses. Here, we report classical mapping strategies for loci in tomato accessions that respond to Cladosporium fulvum effector Ecp5, which is very sequence-monomorphic. We screened 139 wild tomato accessions for an Ecp5-induced hypersensitive response, and in five accessions, the Ecp5-induced hypersensitive response segregated as a monogenic trait, mapping to distinct loci in the tomato genome. We identified at least three loci on chromosomes 1, 7 and 12 that harbor distinct Cf-Ecp5 genes in four different accessions. Our mapping showed that the Cf-Ecp5 in Solanum pimpinellifolium G1.1161 is located at the Milky Way locus. The Cf-Ecp5 in Solanum pimpinellifolium LA0722 was mapped to the bottom arm of chromosome 7, while the Cf-Ecp5 genes in Solanum lycopersicum Ontario 7522 and Solanum pimpinellifolium LA2852 were mapped to the same locus on the top arm of chromosome 12. Bi-parental crosses between accessions carrying distinct Cf-Ecp5 genes revealed putative genetically unlinked suppressors of the Ecp5-induced hypersensitive response. Our mapping also showed that Cf-11 is located on chromosome 11, close to the Cf-3 locus. The Ecp5-induced hypersensitive response is widely distributed within tomato species and is variable in strength. This novel example of convergent evolution could be used for choosing different functional Cf-Ecp5 genes according to individual plant breeding needs.
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Affiliation(s)
- Michail Iakovidis
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Eleni Soumpourou
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Elisabeth Anderson
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | | | - Scott Yourstone
- Department of Biological Sciences, University of North Carolina at Chapel Hill, NC, 27510
| | - Colwyn Thomas
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
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18
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Human MP, Berger DK, Crampton BG. Time-Course RNAseq Reveals Exserohilum turcicum Effectors and Pathogenicity Determinants. Front Microbiol 2020; 11:360. [PMID: 32265851 PMCID: PMC7099616 DOI: 10.3389/fmicb.2020.00360] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/18/2020] [Indexed: 11/16/2022] Open
Abstract
Exserohilum turcicum (sexual stage Setosphaeria turcica) is the hemibiotrophic causal agent of northern leaf blight of maize and sorghum. This study aimed to identify the genes involved in host colonization during the biotrophic and necrotrophic phases of infection. It also aimed to identify race-specific differences in gene expression. RNAseq of maize seedlings inoculated with a race 13N or 23N E. turcicum isolate was conducted before inoculation and at 2, 5, 7, and 13 days post-inoculation (dpi). Biological replicates were pooled per time point for each race and sequenced. A bioinformatics pipeline was used to identify candidate effectors, and expression was validated for selected candidates. Fungal biomass was positively correlated with the percentages of E. turcicum reads mapped, which were low at early time points (2-7 dpi) with a significant increase at 13 dpi, indicating a lifestyle switch from biotrophy to necrotrophy between 7 and 13 dpi. AVRHt1 is the putative E. turcicum effector recognized by the maize resistance gene Ht1. Consistent with this, AVRHt1 was expressed in planta by race 23N, but transcripts were absent in race 13N. In addition, specific transposable elements were expressed in 23N only. Genes encoding the virulence-associated peptidases leupeptin-inhibiting protein 1 and fungalysin were expressed in planta. Transcriptional profiles of genes involved in secondary metabolite synthesis or cell wall degradation revealed the importance of these genes during late stages of infection (13 dpi). A total of 346 expressed candidate effectors were identified, including Ecp6 and proteins similar to the secreted in xylem (SIX) effectors common to formae speciales of Fusarium oxysporum, SIX13 and SIX5. Expression profiling of Ecp6 and SIX13-like indicated a peak in expression at 5 and 7 dpi compared to 2 and 13 dpi. Sequencing of SIX13-like from diverse isolates of E. turcicum revealed host-specific polymorphisms that were mostly non-synonymous, resulting in two groups of SIX13-like proteins that corresponded to the maize or sorghum origin of each isolate. This study suggests putative mechanisms whereby E. turcicum causes disease. Identification of the candidate effector SIX13-like is consistent with the infection mode of E. turcicum through the xylem of susceptible hosts.
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Affiliation(s)
| | | | - Bridget Genevieve Crampton
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Guo Y, Hunziker L, Mesarich CH, Chettri P, Dupont PY, Ganley RJ, McDougal RL, Barnes I, Bradshaw RE. DsEcp2-1 is a polymorphic effector that restricts growth of Dothistroma septosporum in pine. Fungal Genet Biol 2020; 135:103300. [PMID: 31730909 DOI: 10.1016/j.fgb.2019.103300] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 11/05/2019] [Accepted: 11/05/2019] [Indexed: 12/22/2022]
Abstract
The detrimental effect of fungal pathogens on forest trees is an increasingly important problem that has implications for the health of our planet. Despite this, the study of molecular plant-microbe interactions in forest trees is in its infancy, and very little is known about the roles of effector molecules from forest pathogens. Dothistroma septosporum causes a devastating needle blight disease of pines, and intriguingly, is closely related to Cladosporium fulvum, a tomato pathogen in which pioneering effector biology studies have been carried out. Here, we studied D. septosporum effectors that are shared with C. fulvum, by comparing gene sequences from global isolates of D. septosporum and assessing effector function in both host and non-host plants. Many of the effectors were predicted to be non-functional in D. septosporum due to their pseudogenization or low expression in planta, suggesting adaptation to lifestyle and host. Effector sequences were polymorphic among a global collection of D. septosporum isolates, but there was no evidence for positive selection. The DsEcp2-1 effector elicited cell death in the non-host plant Nicotiana tabacum, whilst D. septosporum DsEcp2-1 mutants showed increased colonization of pine needles. Together these results suggest that DsEcp2-1 might be recognized by an immune receptor in both angiosperm and gymnosperm plants. This work may lead to the identification of plant targets for DsEcp2-1 that will provide much needed information on the molecular basis of gymnosperm-pathogen interactions in forests, and may also lead to novel methods of disease control.
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Affiliation(s)
- Yanan Guo
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand.
| | - Lukas Hunziker
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand
| | - Carl H Mesarich
- Bio-Protection Research Centre, School of Agriculture and Environment, Massey University, Palmerston North 4474, New Zealand
| | - Pranav Chettri
- AgResearch Ltd, Grasslands Research Centre, Palmerston North, New Zealand
| | - Pierre-Yves Dupont
- Institute of Environmental Science and Research, Christchurch 8041, New Zealand
| | - Rebecca J Ganley
- The New Zealand Institute for Plant & Food Research Limited, Te Puke, New Zealand
| | - Rebecca L McDougal
- Scion, New Zealand Forest Research Institute Ltd, Rotorua 3010, New Zealand
| | - Irene Barnes
- Department of Genetics, Biochemistry and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, South Africa
| | - Rosie E Bradshaw
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North 4474, New Zealand
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Volk H, Marton K, Flajšman M, Radišek S, Tian H, Hein I, Podlipnik Č, Thomma BPHJ, Košmelj K, Javornik B, Berne S. Chitin-Binding Protein of Verticillium nonalfalfae Disguises Fungus from Plant Chitinases and Suppresses Chitin-Triggered Host Immunity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1378-1390. [PMID: 31063047 DOI: 10.1094/mpmi-03-19-0079-r] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
During fungal infections, plant cells secrete chitinases, which digest chitin in the fungal cell walls. The recognition of released chitin oligomers via lysin motif (LysM)-containing immune host receptors results in the activation of defense signaling pathways. We report here that Verticillium nonalfalfae, a hemibiotrophic xylem-invading fungus, prevents these digestion and recognition processes by secreting a carbohydrate-binding motif 18 (CBM18)-chitin-binding protein, VnaChtBP, which is transcriptionally activated specifically during the parasitic life stages. VnaChtBP is encoded by the Vna8.213 gene, which is highly conserved within the species, suggesting high evolutionary stability and importance for the fungal lifestyle. In a pathogenicity assay, however, Vna8.213 knockout mutants exhibited wilting symptoms similar to the wild-type fungus, suggesting that Vna8.213 activity is functionally redundant during fungal infection of hop. In a binding assay, recombinant VnaChtBP bound chitin and chitin oligomers in vitro with submicromolar affinity and protected fungal hyphae from degradation by plant chitinases. Moreover, the chitin-triggered production of reactive oxygen species from hop suspension cells was abolished in the presence of VnaChtBP, indicating that VnaChtBP also acts as a suppressor of chitin-triggered immunity. Using a yeast-two-hybrid assay, circular dichroism, homology modeling, and molecular docking, we demonstrated that VnaChtBP forms dimers in the absence of ligands and that this interaction is stabilized by the binding of chitin hexamers with a similar preference in the two binding sites. Our data suggest that, in addition to chitin-binding LysM (CBM50) and Avr4 (CBM14) fungal effectors, structurally unrelated CBM18 effectors have convergently evolved to prevent hydrolysis of the fungal cell wall against plant chitinases and to interfere with chitin-triggered host immunity.
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Affiliation(s)
- Helena Volk
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Kristina Marton
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Marko Flajšman
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Sebastjan Radišek
- Slovenian Institute of Hop Research and Brewing, Cesta Žalskega tabora 2, SI-3310 Žalec, Slovenia
| | - Hui Tian
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Ingo Hein
- The James Hutton Institute (JHI), Invergowrie, Dundee DD2 5DA, Scotland, U.K
- The University of Dundee, School of Life Sciences, Division of Plant Sciences at the JHI, Invergowrie
| | - Črtomir Podlipnik
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Bart P H J Thomma
- Laboratory of Phytopathology, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Katarina Košmelj
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Branka Javornik
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
| | - Sabina Berne
- Department of Agronomy, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
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Zuo W, Ökmen B, Depotter JRL, Ebert MK, Redkar A, Misas Villamil J, Doehlemann G. Molecular Interactions Between Smut Fungi and Their Host Plants. ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:411-430. [PMID: 31337276 DOI: 10.1146/annurev-phyto-082718-100139] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Smut fungi are a large group of biotrophic plant pathogens that infect mostly monocot species, including economically relevant cereal crops. For years, Ustilago maydis has stood out as the model system to study the genetics and cell biology of smut fungi as well as the pathogenic development of biotrophic plant pathogens. The identification and functional characterization of secreted effectors and their role in virulence have particularly been driven forward using the U. maydis-maize pathosystem. Today, advancing tools for additional smut fungi such as Ustilago hordei and Sporisorium reilianum, as well as an increasing number of available genome sequences, provide excellent opportunities to investigate in parallel the effector function and evolution associated with different lifestyles and host specificities. In addition, genome analyses revealed similarities in the genomic signature between pathogenic smuts and epiphytic Pseudozyma species. This review elaborates on how knowledge about fungal lifestyles, genome biology, and functional effector biology has helped in understanding the biology of this important group of fungal pathogens. We highlight the contribution of the U. maydis model system but also discuss the differences from other smut fungi, which raises the importance of comparative genomic and genetic analyses in future research.
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Affiliation(s)
- Weiliang Zuo
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
| | - Bilal Ökmen
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
| | - Jasper R L Depotter
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
| | - Malaika K Ebert
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
| | - Amey Redkar
- Current affiliation: Department of Genetics, University of Córdoba, 14071 Córdoba, Spain
| | - Johana Misas Villamil
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
| | - Gunther Doehlemann
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674 Cologne, Germany;
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Prasad Singh P, Srivastava D, Jaiswar A, Adholeya A. Effector proteins of Rhizophagus proliferus: conserved protein domains may play a role in host-specific interaction with different plant species. Braz J Microbiol 2019; 50:593-601. [PMID: 31250404 PMCID: PMC6863257 DOI: 10.1007/s42770-019-00099-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/29/2019] [Indexed: 12/27/2022] Open
Abstract
Arbuscular mycorrhizal (AM) fungi show high promiscuity in terms of host. Effector proteins expressed by AM fungi are found important in establishing interaction with host. However, the mechanistic underlying host-specific interactions of the fungi remain unknown. The present study aimed (i) to identify effectors encoded by Rhizophagus proliferus and (ii) to understand molecular specificity encoded in effectors for interaction with specific plant species. The effectors predicted from the whole genome sequence were annotated by homology search in NCBI non-redundant protein, Interproscan, and pathogen-host interaction (PHI) databases. In total, 416 small secreted peptides (SSPs) were predicted, which were effector peptides with presence of nuclear localization signal, small cysteine-rich, and repeat-containing proteins domains. Similar to the functionally validated SP7 effectors in Rhizophagus irregularis, two proteins (RP8598 and RP23081) were identified in R. proliferus. To understand whether interaction between SP7 and the plant target protein, ERF19, is specific in nature, we examined protein-peptide interaction using in silico molecular docking. Pairwise interaction of RP8598 and RP23081 with the ethylene-responsive factors (ERF19) coded by five different plant species (Lotus japonicus, Solanum lycopersicum, Ocimum tenuiflorum, Medicago truncatula, Diospyros kaki) was investigated. Prediction of high-quality interaction of SP7 effector with ERF19 protein expressed only by specific plant species was observed in in silico molecular docking, which may reiterate the role of effectors in host specificity. The outcomes from our study indicated that sequence precision encoded in the effector peptides of AM fungi and immunomodulatory proteins of host may regulate host specificity in these fungi.
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Affiliation(s)
- Pushplata Prasad Singh
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gwal Pahari, Gurgaon Faridabad Road, Gurugram, Haryana, 122001, India.
| | - Divya Srivastava
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gwal Pahari, Gurgaon Faridabad Road, Gurugram, Haryana, 122001, India
| | - Akanksha Jaiswar
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gwal Pahari, Gurgaon Faridabad Road, Gurugram, Haryana, 122001, India
| | - Alok Adholeya
- TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gwal Pahari, Gurgaon Faridabad Road, Gurugram, Haryana, 122001, India
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An B, Hou X, Guo Y, Zhao S, Luo H, He C, Wang Q. The effector SIX8 is required for virulence of Fusarium oxysporum f.sp. cubense tropical race 4 to Cavendish banana. Fungal Biol 2019; 123:423-430. [DOI: 10.1016/j.funbio.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 03/03/2019] [Accepted: 03/05/2019] [Indexed: 01/10/2023]
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24
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Olukayode T, Quime B, Shen YC, Yanoria MJ, Zhang S, Yang J, Zhu X, Shen WC, von Tiedemann A, Zhou B. Dynamic Insertion of Pot3 in AvrPib Prevailing in a Field Rice Blast Population in the Philippines Led to the High Virulence Frequency Against the Resistance Gene Pib in Rice. PHYTOPATHOLOGY 2019; 109:870-877. [PMID: 30501464 DOI: 10.1094/phyto-06-18-0198-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The Magnaporthe oryzae avirulence gene AvrPib is required for the resistance mediated by its cognate resistance gene Pib, which has been intensively used in indica rice breeding programs in many Asian countries. However, the sequence diversity of AvrPib among geographically distinct M. oryzae populations was recently shown to be increasing. Here, we selected a field population consisting of 248 rice blast isolates collected from a disease hotspot in Philippine for the analysis of AvrPib haplotypes and their pathogenicity against Pib. We found that all of the isolates were virulent to Pib and each of them contained an insertion of Pot3 transposon in AvrPib. Moreover, Pot3 insertion was detected in different genomic positions, resulting in three different AvrPib haplotypes, designated avrPib-H1 to H3. We further conducted a genome-wide Pot2 fingerprinting analysis by repetitive element palindromic polymerase chain reaction (PCR) and identified seven different lineages out of 47 representative isolates. The isolates belonging to the same lineage often had the same AvrPib haplotype. In contrast, the isolates having the same AvrPib haplotypes did not always belong to the same lineages. Both mating types MAT1-1 and MAT1-2 were identified in the population in Bohol and the latter appeared dominant. On the host side, we found that 32 of 52 released rice varieties in the Philippines contained Pib diagnosed by PCR gene-specific primers and DNA sequencing of gene amplicons, suggesting that it was widely incorporated in different rice varieties. Our study highlights the genetic dynamics of rice blast population at both the AvrPib locus and the genome-wide levels, providing insight into the mechanisms of the mutations in AvrPib leading to the breakdown of Pib-mediated resistance in rice.
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Affiliation(s)
- Toluwase Olukayode
- 1 Division of Plant Pathology and Crop Protection, Department of Crop Sciences, Faculty of Agricultural Sciences, Georg-August University, Grisebachstraße 6, D-37077 Göttingen, Germany
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Berlaine Quime
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Yin-Chi Shen
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
- 3 Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan
| | - Mary Jeannie Yanoria
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Suobing Zhang
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
- 4 Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; and
| | - Jianyuan Yang
- 5 Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Xiaoyuan Zhu
- 5 Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Wei-Chiang Shen
- 3 Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan
| | - Andreas von Tiedemann
- 1 Division of Plant Pathology and Crop Protection, Department of Crop Sciences, Faculty of Agricultural Sciences, Georg-August University, Grisebachstraße 6, D-37077 Göttingen, Germany
| | - Bo Zhou
- 2 International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
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Mesarich CH, Ӧkmen B, Rovenich H, Griffiths SA, Wang C, Karimi Jashni M, Mihajlovski A, Collemare J, Hunziker L, Deng CH, van der Burgt A, Beenen HG, Templeton MD, Bradshaw RE, de Wit PJGM. Specific Hypersensitive Response-Associated Recognition of New Apoplastic Effectors from Cladosporium fulvum in Wild Tomato. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:145-162. [PMID: 29144204 DOI: 10.1094/mpmi-05-17-0114-fi] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Tomato leaf mold disease is caused by the biotrophic fungus Cladosporium fulvum. During infection, C. fulvum produces extracellular small secreted protein (SSP) effectors that function to promote colonization of the leaf apoplast. Resistance to the disease is governed by Cf immune receptor genes that encode receptor-like proteins (RLPs). These RLPs recognize specific SSP effectors to initiate a hypersensitive response (HR) that renders the pathogen avirulent. C. fulvum strains capable of overcoming one or more of all cloned Cf genes have now emerged. To combat these strains, new Cf genes are required. An effectoromics approach was employed to identify wild tomato accessions carrying new Cf genes. Proteomics and transcriptome sequencing were first used to identify 70 apoplastic in planta-induced C. fulvum SSPs. Based on sequence homology, 61 of these SSPs were novel or lacked known functional domains. Seven, however, had predicted structural homology to antimicrobial proteins, suggesting a possible role in mediating antagonistic microbe-microbe interactions in planta. Wild tomato accessions were then screened for HR-associated recognition of 41 SSPs, using the Potato virus X-based transient expression system. Nine SSPs were recognized by one or more accessions, suggesting that these plants carry new Cf genes available for incorporation into cultivated tomato.
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Affiliation(s)
- Carl H Mesarich
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- 2 Laboratory of Molecular Plant Pathology, Institute of Agriculture & Environment, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
- 3 Bio-Protection Research Centre, New Zealand
| | - Bilal Ӧkmen
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Hanna Rovenich
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Scott A Griffiths
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Changchun Wang
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- 4 College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, People's Republic of China
| | - Mansoor Karimi Jashni
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- 5 Department of Plant Pathology, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization, P.O. Box 19395‒1454, Tehran, Iran
| | - Aleksandar Mihajlovski
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jérôme Collemare
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Lukas Hunziker
- 3 Bio-Protection Research Centre, New Zealand
- 6 Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - Cecilia H Deng
- 7 Breeding & Genomics/Bioprotection Portfolio, the New Zealand Institute for Plant & Food Research Limited, Mount Albert Research Centre, Auckland 1025, New Zealand; and
| | - Ate van der Burgt
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Henriek G Beenen
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Matthew D Templeton
- 3 Bio-Protection Research Centre, New Zealand
- 7 Breeding & Genomics/Bioprotection Portfolio, the New Zealand Institute for Plant & Food Research Limited, Mount Albert Research Centre, Auckland 1025, New Zealand; and
| | - Rosie E Bradshaw
- 3 Bio-Protection Research Centre, New Zealand
- 6 Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - Pierre J G M de Wit
- 1 Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
- 8 Centre for BioSystems Genomics, P.O. Box 98, 6700 AB Wageningen, The Netherlands
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Ashwin NMR, Barnabas L, Ramesh Sundar A, Malathi P, Viswanathan R, Masi A, Agrawal GK, Rakwal R. Advances in proteomic technologies and their scope of application in understanding plant–pathogen interactions. JOURNAL OF PLANT BIOCHEMISTRY AND BIOTECHNOLOGY 2017. [DOI: 10.1007/s13562-017-0402-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Yang B, Wang Q, Jing M, Guo B, Wu J, Wang H, Wang Y, Lin L, Wang Y, Ye W, Dong S, Wang Y. Distinct regions of the Phytophthora essential effector Avh238 determine its function in cell death activation and plant immunity suppression. THE NEW PHYTOLOGIST 2017; 214:361-375. [PMID: 28134441 DOI: 10.1111/nph.14430] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/09/2016] [Indexed: 05/20/2023]
Abstract
Phytophthora pathogens secrete effectors to manipulate host innate immunity, thus facilitating infection. Among the RXLR effectors highly induced during Phytophthora sojae infection, Avh238 not only contributes to pathogen virulence but also triggers plant cell death. However, the detailed molecular basis of Avh238 functions remains largely unknown. We mapped the regions responsible for Avh238 functions in pathogen virulence and plant cell death induction using a strategy that combines investigation of natural variation and large-scale mutagenesis assays. The correlation between cellular localization and Avh238 functions was also evaluated. We found that the 79th residue (histidine or leucine) of Avh238 determined its cell death-inducing activity, and that the 53 amino acids in its C-terminal region are responsible for promoting Phytophthora infection. Transient expression of Avh238 in Nicotiana benthamiana revealed that nuclear localization is essential for triggering cell death, while Avh238-mediated suppression of INF1-triggered cell death requires cytoplasmic localization. Our results demonstrate that a representative example of an essential Phytophthora RXLR effector can evolve to escape recognition by the host by mutating one nucleotide site, and can also retain plant immunosuppressive activity to enhance pathogen virulence in planta.
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Affiliation(s)
- Bo Yang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Qunqing Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
- Department of Plant Pathology, Shandong Agricultural University, Taian, 271018, China
| | - Maofeng Jing
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Baodian Guo
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Jiawei Wu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Haonan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yang Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Long Lin
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Suomeng Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, 210095, China
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Schmidt SM, Lukasiewicz J, Farrer R, van Dam P, Bertoldo C, Rep M. Comparative genomics of Fusarium oxysporum f. sp. melonis reveals the secreted protein recognized by the Fom-2 resistance gene in melon. THE NEW PHYTOLOGIST 2016; 209:307-18. [PMID: 26305378 PMCID: PMC5769816 DOI: 10.1111/nph.13584] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 06/29/2015] [Indexed: 05/06/2023]
Abstract
Development of resistant crops is the most effective way to control plant diseases to safeguard food and feed production. Disease resistance is commonly based on resistance genes, which generally mediate the recognition of small proteins secreted by invading pathogens. These proteins secreted by pathogens are called 'avirulence' proteins. Their identification is important for being able to assess the usefulness and durability of resistance genes in agricultural settings. We have used genome sequencing of a set of strains of the melon wilt fungus Fusarium oxysporum f. sp. melonis (Fom), bioinformatics-based genome comparison and genetic transformation of the fungus to identify AVRFOM2, the gene that encodes the avirulence protein recognized by the melon Fom-2 gene. Both an unbiased and a candidate gene approach identified a single candidate for the AVRFOM2 gene. Genetic complementation of AVRFOM2 in three different race 2 isolates resulted in resistance of Fom-2-harbouring melon cultivars. AvrFom2 is a small, secreted protein with two cysteine residues and weak similarity to secreted proteins of other fungi. The identification of AVRFOM2 will not only be helpful to select melon cultivars to avoid melon Fusarium wilt, but also to monitor how quickly a Fom population can adapt to deployment of Fom-2-containing cultivars in the field.
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Affiliation(s)
- Sarah Maria Schmidt
- Molecular Plant Pathology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
| | - Joanna Lukasiewicz
- Molecular Plant Pathology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
| | - Rhys Farrer
- Genome Sequencing and Analysis Program, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Peter van Dam
- Molecular Plant Pathology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
| | - Chiara Bertoldo
- Molecular Plant Pathology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
| | - Martijn Rep
- Molecular Plant Pathology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, 1090 GE, Amsterdam, the Netherlands
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Mesarich CH, Stergiopoulos I, Beenen HG, Cordovez V, Guo Y, Karimi Jashni M, Bradshaw RE, de Wit PJGM. A conserved proline residue in Dothideomycete Avr4 effector proteins is required to trigger a Cf-4-dependent hypersensitive response. MOLECULAR PLANT PATHOLOGY 2016; 17:84-95. [PMID: 25845605 PMCID: PMC6638486 DOI: 10.1111/mpp.12265] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
CfAvr4, a chitin-binding effector protein produced by the Dothideomycete tomato pathogen Cladosporium fulvum, protects the cell wall of this fungus against hydrolysis by secreted host chitinases during infection. However, in the presence of the Cf-4 immune receptor of tomato, CfAvr4 triggers a hypersensitive response (HR), which renders the pathogen avirulent. Recently, several orthologues of CfAvr4 have been identified from phylogenetically closely related species of Dothideomycete fungi. Of these, DsAvr4 from Dothistroma septosporum also triggers a Cf-4-dependent HR, but CaAvr4 and CbAvr4 from Cercospora apii and Cercospora beticola, respectively, do not. All, however, bind chitin. To identify the region(s) and specific amino acid residue(s) of CfAvr4 and DsAvr4 required to trigger a Cf-4-dependent HR, chimeric and mutant proteins, in which specific protein regions or single amino acid residues, respectively, were exchanged between CfAvr4 and CaAvr4 or DsAvr4 and CbAvr4, were tested for their ability to trigger an HR in Nicotiana benthamiana plants transgenic for the Cf-4 immune receptor gene. Based on this approach, a single region common to CfAvr4 and DsAvr4 was determined to carry a conserved proline residue necessary for the elicitation of this HR. In support of this result, a Cf-4-dependent HR was triggered by mutant CaAvr4 and CbAvr4 proteins carrying an arginine-to-proline substitution at this position. This study provides the first step in deciphering how Avr4 orthologues from different Dothideomycete fungi trigger a Cf-4-dependent HR.
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Affiliation(s)
- Carl H Mesarich
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Ioannis Stergiopoulos
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
- Department of Plant Pathology, University of California Davis, One Shield Avenue, Davis, CA, 95616-8751, USA
- Centre for BioSystems Genomics, PO Box 98, 6700 AB, Wageningen, the Netherlands
| | - Henriek G Beenen
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Viviane Cordovez
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Yanan Guo
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Mansoor Karimi Jashni
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
- Department of Plant Pathology, Tarbiat Modares University, PO Box 14115-336, Tehran, Iran
| | - Rosie E Bradshaw
- Bio-Protection Research Centre, Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Pierre J G M de Wit
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
- Centre for BioSystems Genomics, PO Box 98, 6700 AB, Wageningen, the Netherlands
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Medina R, López SMY, Franco MEE, Rollan C, Ronco BL, Saparrat MCN, De Wit PJGM, Balatti PA. A Survey on Occurrence of Cladosporium fulvum Identifies Race 0 and Race 2 in Tomato-Growing Areas of Argentina. PLANT DISEASE 2015; 99:1732-1737. [PMID: 30699511 DOI: 10.1094/pdis-12-14-1270-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The presence of Cladosporium fulvum (syn. Passalora fulva), causal agent of tomato leaf mold, was confirmed in the two main greenhouse-production areas for tomato in Argentina. Using both morphological characters and internal transcribed spacer sequencing, we confirmed the presence of physiological races of this pathogen. A diagnostic multiplex polymerase chain reaction (PCR) was also developed, using primers derived from C. fulvum avirulence (Avr) genes. In all, 20 isolates of Cladosporium spp. were obtained as monospore cultures and 12 were identified as C. fulvum. By this method, we showed that, of these 12 isolates, 5 were race 0 (carrying functional Avr2, Avr4, Avr4E, and Avr9 genes) and 7 were race 2 (lacking the Avr2 gene). Race identity was confirmed by testing their virulence on a set of tomato differentials carrying different Cf resistance genes. All Avr genes could be amplified in single or multiplex PCR using DNA isolated from in vitro grown monospore cultures but only three Avr could be amplified when genomic DNA was isolated from C. fulvum-infected necrotic leaf tissue.
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Affiliation(s)
- Rocío Medina
- Centro de Investigaciones en Fitopatologías (CIDEFI), La Plata (1900), Argentina; and Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI), La Plata (1900), Argentina
| | - Silvina M Y López
- Instituto de Fisiología Vegetal (INFIVE), La Plata (1900), Argentina
| | | | | | | | | | - Pierre J G M De Wit
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Pedro A Balatti
- CIDEFI, La Plata (1900), Argentina; and Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, Argentina
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Poppe S, Dorsheimer L, Happel P, Stukenbrock EH. Rapidly Evolving Genes Are Key Players in Host Specialization and Virulence of the Fungal Wheat Pathogen Zymoseptoria tritici (Mycosphaerella graminicola). PLoS Pathog 2015. [PMID: 26225424 PMCID: PMC4520584 DOI: 10.1371/journal.ppat.1005055] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The speciation of pathogens can be driven by divergent host specialization. Specialization to a new host is possible via the acquisition of advantageous mutations fixed by positive selection. Comparative genome analyses of closely related species allows for the identification of such key substitutions via inference of genome-wide signatures of positive selection. We previously used a comparative genomics framework to identify genes that have evolved under positive selection during speciation of the prominent wheat pathogen Zymoseptoria tritici (synonym Mycosphaerella graminicola). In this study, we conducted functional analyses of four genes exhibiting strong signatures of positive selection in Z. tritici. We deleted the four genes in Z. tritici and confirm a virulence-related role of three of the four genes ΔZt80707, ΔZt89160 and ΔZt103264. The two mutants ΔZt80707 and ΔZt103264 show a significant reduction in virulence during infection of wheat; the ΔZt89160 mutant causes a hypervirulent phenotype in wheat. Mutant phenotypes of ΔZt80707, ΔZt89160 and ΔZt103264 can be restored by insertion of the wild-type genes. However, the insertion of the Zt80707 and Zt89160 orthologs from Z. pseudotritici and Z. ardabiliae do not restore wild-type levels of virulence, suggesting that positively selected substitutions in Z. tritici may relate to divergent host specialization. Interestingly, the gene Zt80707 encodes also a secretion signal that targets the protein for cell secretion. This secretion signal is however only transcribed in Z. tritici, suggesting that Z. tritici-specific substitutions relate to a new function of the protein in the extracellular space of the wheat-Z. tritici interaction. Together, the results presented here highlight that Zt80707, Zt103264 and Zt89160 represent key genes involved in virulence and host-specific disease development of Z. tritici. Our findings illustrate that evolutionary predictions provide a powerful tool for the identification of novel traits crucial for host adaptation and pathogen evolution. Zymoseptoria spp provides a unique model system to study the underlying genetics of host specialization of plant pathogens. Closely related Zymoseptoria species, including the prominent wheat pathogen Z. tritici, have recently specialized to distinct grass hosts. Positively selected substitutions have played a central role in the acquisition of new host specificities. We have identified a small set of genes showing signatures of positive selection. We demonstrate that three of these four candidate genes play an important role during host infection. Two mutants of Z. tritici were impaired in virulence; a third mutant showed a hypervirulent phenotype. New protein specificities not only include changes at the amino acid sequence level but also at the level of the protein structure. We conducted a gene replacement experiment to test if mutant phenotypes in Z. tritici could be complemented by the insertion of orthologous genes from the two closely related species Z. pseudotritici and Z. ardabiliae. For two genes, we confirm that the species-specific protein changes are essential for proper protein functioning in Z. tritici; key traits involved in the evolution of virulence and host specificity of this prominent pathogen can be characterized via a combination of evolutionary predictions and functional analyses.
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Affiliation(s)
- Stephan Poppe
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Lena Dorsheimer
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Petra Happel
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Eva Holtgrewe Stukenbrock
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
- * E-mail:
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Hemetsberger C, Mueller AN, Matei A, Herrberger C, Hensel G, Kumlehn J, Mishra B, Sharma R, Thines M, Hückelhoven R, Doehlemann G. The fungal core effector Pep1 is conserved across smuts of dicots and monocots. THE NEW PHYTOLOGIST 2015; 206:1116-1126. [PMID: 25628012 DOI: 10.1111/nph.13304] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/16/2014] [Indexed: 05/03/2023]
Abstract
The secreted fungal effector Pep1 is essential for penetration of the host epidermis and establishment of biotrophy in the Ustilago maydis-maize pathosystem. Previously, Pep1 was found to be an inhibitor of apoplastic plant peroxidases, which suppresses the oxidative burst, a primary immune response of the host plant and enables fungal colonization. To investigate the conservation of Pep1 in other pathogens, genomes of related smut species were screened for pep1 orthologues. Pep1 proteins were produced in Escherichia coli for functional assays. The biological function of Pep1 was tested by heterologous expression in U. maydis and Hordeum vulgare. Pep1 orthologues revealed a remarkable degree of sequence conservation, indicating that this effector might play a fundamental role in virulence of biotrophic smut fungi. Pep1 function and its role in virulence are conserved in different pathogenic fungi, even across the monocot-dicot border of host plants. The findings described in this study classify Pep1 as a phylogenetically conserved fungal core effector. Furthermore, we documented the influence of Pep1 on the disease caused by Blumeria graminis f. sp. hordei which is a non-smut-related pathosystem.
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Affiliation(s)
- Christoph Hemetsberger
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany
- Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Str. 2, D-85350, Freising-Weihenstephan, Germany
| | - André N Mueller
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany
| | - Alexandra Matei
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany
| | - Christian Herrberger
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany
| | - Götz Hensel
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Plant Reproductive Biology, D-06466, Stadt Seeland/OT Gatersleben, Germany
| | - Jochen Kumlehn
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Plant Reproductive Biology, D-06466, Stadt Seeland/OT Gatersleben, Germany
| | - Bagdevi Mishra
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany
- Integrative Fungal Research Cluster (IPF), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany
- Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt am Main, Max-von-Laue-Str. 13, D-60438, Frankfurt am Main, Germany
| | - Rahul Sharma
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany
- Integrative Fungal Research Cluster (IPF), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany
- Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt am Main, Max-von-Laue-Str. 13, D-60438, Frankfurt am Main, Germany
| | - Marco Thines
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325, Frankfurt am Main, Germany
- Integrative Fungal Research Cluster (IPF), Georg-Voigt-Str. 14-16, D-60325, Frankfurt am Main, Germany
- Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt am Main, Max-von-Laue-Str. 13, D-60438, Frankfurt am Main, Germany
| | - Ralph Hückelhoven
- Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann-Str. 2, D-85350, Freising-Weihenstephan, Germany
| | - Gunther Doehlemann
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, D-35043, Marburg, Germany
- Botanical Institute and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Biocenter, Zuelpicher Str. 47a, 50674 Cologne, Germany
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Iida Y, van ‘t Hof P, Beenen H, Mesarich C, Kubota M, Stergiopoulos I, Mehrabi R, Notsu A, Fujiwara K, Bahkali A, Abd-Elsalam K, Collemare J, de Wit PJGM. Novel Mutations Detected in Avirulence Genes Overcoming Tomato Cf Resistance Genes in Isolates of a Japanese Population of Cladosporium fulvum. PLoS One 2015; 10:e0123271. [PMID: 25902074 PMCID: PMC4406682 DOI: 10.1371/journal.pone.0123271] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/19/2015] [Indexed: 12/15/2022] Open
Abstract
Leaf mold of tomato is caused by the biotrophic fungus Cladosporium fulvum which complies with the gene-for-gene system. The disease was first reported in Japan in the 1920s and has since been frequently observed. Initially only race 0 isolates were reported, but since the consecutive introduction of resistance genes Cf-2, Cf-4, Cf-5 and Cf-9 new races have evolved. Here we first determined the virulence spectrum of 133 C. fulvum isolates collected from 22 prefectures in Japan, and subsequently sequenced the avirulence (Avr) genes Avr2, Avr4, Avr4E, Avr5 and Avr9 to determine the molecular basis of overcoming Cf genes. Twelve races of C. fulvum with a different virulence spectrum were identified, of which races 9, 2.9, 4.9, 4.5.9 and 4.9.11 occur only in Japan. The Avr genes in many of these races contain unique mutations not observed in races identified elsewhere in the world including (i) frameshift mutations and (ii) transposon insertions in Avr2, (iii) point mutations in Avr4 and Avr4E, and (iv) deletions of Avr4E, Avr5 and Avr9. New races have developed by selection pressure imposed by consecutive introductions of Cf-2, Cf-4, Cf-5 and Cf-9 genes in commercially grown tomato cultivars. Our study shows that molecular variations to adapt to different Cf genes in an isolated C. fulvum population in Japan are novel but overall follow similar patterns as those observed in populations from other parts of the world. Implications for breeding of more durable C. fulvum resistant varieties are discussed.
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Affiliation(s)
- Yuichiro Iida
- National Agriculture and Food Research Organization, Tsu, Mie, Japan
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Pieter van ‘t Hof
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Henriek Beenen
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Carl Mesarich
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Masaharu Kubota
- National Agriculture and Food Research Organization, Tsu, Mie, Japan
| | | | - Rahim Mehrabi
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
- Seed and Plant Improvement Institute, Karaj, Iran
| | - Ayumi Notsu
- Hokkaido Research Organization, Ornamental Plants and Vegetables Research Center, Hokkaido, Japan
| | - Kazuki Fujiwara
- National Agriculture and Food Research Organization, Tsu, Mie, Japan
| | - Ali Bahkali
- King Saud University, College of Science, Botany and Microbiology Department, Riyadh, Saudi Arabia
| | - Kamel Abd-Elsalam
- King Saud University, College of Science, Botany and Microbiology Department, Riyadh, Saudi Arabia
- Plant Pathology Research Institute, Agricultural Research Center, Giza, Egypt
| | - Jérôme Collemare
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
| | - Pierre J. G. M. de Wit
- Wageningen University, Laboratory of Phytopathology, Wageningen, The Netherlands
- Centre for Biosystems Genomics, Wageningen, The Netherlands
- * E-mail:
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Mesarich CH, Bowen JK, Hamiaux C, Templeton MD. Repeat-containing protein effectors of plant-associated organisms. FRONTIERS IN PLANT SCIENCE 2015; 6:872. [PMID: 26557126 PMCID: PMC4617103 DOI: 10.3389/fpls.2015.00872] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/01/2015] [Indexed: 05/10/2023]
Abstract
Many plant-associated organisms, including microbes, nematodes, and insects, deliver effector proteins into the apoplast, vascular tissue, or cell cytoplasm of their prospective hosts. These effectors function to promote colonization, typically by altering host physiology or by modulating host immune responses. The same effectors however, can also trigger host immunity in the presence of cognate host immune receptor proteins, and thus prevent colonization. To circumvent effector-triggered immunity, or to further enhance host colonization, plant-associated organisms often rely on adaptive effector evolution. In recent years, it has become increasingly apparent that several effectors of plant-associated organisms are repeat-containing proteins (RCPs) that carry tandem or non-tandem arrays of an amino acid sequence or structural motif. In this review, we highlight the diverse roles that these repeat domains play in RCP effector function. We also draw attention to the potential role of these repeat domains in adaptive evolution with regards to RCP effector function and the evasion of effector-triggered immunity. The aim of this review is to increase the profile of RCP effectors from plant-associated organisms.
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Affiliation(s)
- Carl H. Mesarich
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
- *Correspondence: Carl H. Mesarich
| | - Joanna K. Bowen
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
| | - Cyril Hamiaux
- Human Responses, The New Zealand Institute for Plant & Food Research LimitedAuckland, New Zealand
| | - Matthew D. Templeton
- School of Biological Sciences, The University of AucklandAuckland, New Zealand
- Host–Microbe Interactions, Bioprotection, The New Zealand Institute for Plant & Food Research LtdAuckland, New Zealand
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Mesarich CH, Griffiths SA, van der Burgt A, Okmen B, Beenen HG, Etalo DW, Joosten MHAJ, de Wit PJGM. Transcriptome sequencing uncovers the Avr5 avirulence gene of the tomato leaf mold pathogen Cladosporium fulvum. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:846-57. [PMID: 24678832 DOI: 10.1094/mpmi-02-14-0050-r] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The Cf-5 gene of tomato confers resistance to strains of the fungal pathogen Cladosporium fulvum carrying the avirulence gene Avr5. Although Cf-5 has been cloned, Avr5 has remained elusive. We report the cloning of Avr5 using a combined bioinformatic and transcriptome sequencing approach. RNA-Seq was performed on the sequenced race 0 strain (0WU; carrying Avr5), as well as a race 5 strain (IPO 1979; lacking a functional Avr5 gene) during infection of susceptible tomato. Forty-four in planta-induced C. fulvum candidate effector (CfCE) genes of 0WU were identified that putatively encode a secreted, small cysteine-rich protein. An expressed transcript sequence comparison between strains revealed two polymorphic CfCE genes in IPO 1979. One of these conferred avirulence to IPO 1979 on Cf-5 tomato following complementation with the corresponding 0WU allele, confirming identification of Avr5. Complementation also led to increased fungal biomass during infection of susceptible tomato, signifying a role for Avr5 in virulence. Seven of eight race 5 strains investigated escape Cf-5-mediated resistance through deletion of the Avr5 gene. Avr5 is heavily flanked by repetitive elements, suggesting that repeat instability, in combination with Cf-5-mediated selection pressure, has led to the emergence of race 5 strains deleted for the Avr5 gene.
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Stergiopoulos I, Cordovez V, Okmen B, Beenen HG, Kema GHJ, de Wit PJGM. Positive selection and intragenic recombination contribute to high allelic diversity in effector genes of Mycosphaerella fijiensis, causal agent of the black leaf streak disease of banana. MOLECULAR PLANT PATHOLOGY 2014; 15:447-60. [PMID: 24245940 PMCID: PMC6638713 DOI: 10.1111/mpp.12104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Previously, we have determined the nonhost-mediated recognition of the MfAvr4 and MfEcp2 effector proteins from the banana pathogen Mycosphaerella fijiensis in tomato, by the cognate Cf-4 and Cf-Ecp2 resistance proteins, respectively. These two resistance proteins could thus mediate resistance against M. fijiensis if genetically transformed into banana (Musa spp.). However, disease resistance controlled by single dominant genes can be overcome by mutated effector alleles, whose products are not recognized by the cognate resistance proteins. Here, we surveyed the allelic variation within the MfAvr4, MfEcp2, MfEcp2-2 and MfEcp2-3 effector genes of M. fijiensis in a global population of the pathogen, and assayed its impact on recognition by the tomato Cf-4 and Cf-Ecp2 resistance proteins, respectively. We identified a large number of polymorphisms that could reflect a co-evolutionary arms race between host and pathogen. The analysis of nucleotide substitution patterns suggests that both positive selection and intragenic recombination have shaped the evolution of M. fijiensis effectors. Clear differences in allelic diversity were observed between strains originating from South-East Asia relative to strains from other banana-producing continents, consistent with the hypothesis that M. fijiensis originated in the Asian-Pacific region. Furthermore, transient co-expression of the MfAvr4 effector alleles and the tomato Cf-4 resistance gene, as well as of MfEcp2, MfEcp2-2 and MfEcp2-3 and the putative Cf-Ecp2 resistance gene, indicated that effector alleles able to overcome these resistance genes are already present in natural populations of the pathogen, thus questioning the durability of resistance that can be provided by these genes in the field.
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Affiliation(s)
- Ioannis Stergiopoulos
- Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA, 95616-8751, USA; Laboratory of Phytopathology, Wageningen University and Research Centre, Droevendaalsesteeg 1, Wageningen, 6708PB, the Netherlands; Centre for BioSystems Genomics, PO Box 98, Wageningen, 6700 AB, the Netherlands
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Guyon K, Balagué C, Roby D, Raffaele S. Secretome analysis reveals effector candidates associated with broad host range necrotrophy in the fungal plant pathogen Sclerotinia sclerotiorum. BMC Genomics 2014; 15:336. [PMID: 24886033 PMCID: PMC4039746 DOI: 10.1186/1471-2164-15-336] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/27/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The white mold fungus Sclerotinia sclerotiorum is a devastating necrotrophic plant pathogen with a remarkably broad host range. The interaction of necrotrophs with their hosts is more complex than initially thought, and still poorly understood. RESULTS We combined bioinformatics approaches to determine the repertoire of S. sclerotiorum effector candidates and conducted detailed sequence and expression analyses on selected candidates. We identified 486 S. sclerotiorum secreted protein genes expressed in planta, many of which have no predicted enzymatic activity and may be involved in the interaction between the fungus and its hosts. We focused on those showing (i) protein domains and motifs found in known fungal effectors, (ii) signatures of positive selection, (iii) recent gene duplication, or (iv) being S. sclerotiorum-specific. We identified 78 effector candidates based on these properties. We analyzed the expression pattern of 16 representative effector candidate genes on four host plants and revealed diverse expression patterns. CONCLUSIONS These results reveal diverse predicted functions and expression patterns in the repertoire of S. sclerotiorum effector candidates. They will facilitate the functional analysis of fungal pathogenicity determinants and should prove useful in the search for plant quantitative disease resistance components active against the white mold.
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Affiliation(s)
| | | | | | - Sylvain Raffaele
- INRA, Laboratoire des Interactions Plantes-Microorganismes (LIPM), UMR441, F-31326, Castanet-Tolosan, France.
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Grandaubert J, Balesdent MH, Rouxel T. [Transposable elements reshaping genomes and favouring the evolutionary and adaptive potential of fungal phytopathogens]. Biol Aujourdhui 2014; 207:277-290. [PMID: 24594576 DOI: 10.1051/jbio/2013026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Indexed: 06/03/2023]
Abstract
Phytopathogenic fungi are a major threat for global food security and show an extreme plasticity in pathogenicity behaviours. They often have a high adaptive potential allowing them to rapidly counteract the control methods used by men in agrosystems. In this paper, we evaluate the link between genome plasticity and adaptive potential using genomics and comparative genomics approaches. Our model is the evolutionary series Leptosphaeria maculans-Leptosphaeria biglobosa, encompassing five distinct entities, whose conspecificity or heterospecificity status is unclear, and which all are pathogens of cruciferous plants. They however differ by their host range and pathogenicity. Compared to other species of the species complex, the species best adapted to oilseed rape, L. maculans "brassicae", causing important losses in the crop, has a genome that was submitted to a recent and massive burst of transposition by a few families of transposable elements (TEs). Whether the genome invasion contributed to speciation is still unclear to-date but there is a coincidence between this burst of TEs and divergence between two species. This TE burst contributed to diversification of effector proteins and thus to generation of novel pathogenic specificities. In addition, the location of effector genes within genome regions enriched in TEs has direct consequences on adaptation to plant resistance and favours a multiplicity of mutation events allowing "breakdown" of resistance. These data are substantiated by other examples in the literature showing that fungi tend to have a "two-speed" genome, in which a plastic compartment enriched in TE host genes is involved in pathogenicity and adaptation to host.
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van der Burgt A, Karimi Jashni M, Bahkali AH, de Wit PJGM. Pseudogenization in pathogenic fungi with different host plants and lifestyles might reflect their evolutionary past. MOLECULAR PLANT PATHOLOGY 2014; 15:133-44. [PMID: 24393451 PMCID: PMC6638865 DOI: 10.1111/mpp.12072] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pseudogenes are genes with significant homology to functional genes, but contain disruptive mutations (DMs) leading to the production of non- or partially functional proteins. Little is known about pseudogenization in pathogenic fungi with different lifestyles. Here, we report the identification of DMs causing pseudogenes in the genomes of the fungal plant pathogens Botrytis cinerea, Cladosporium fulvum, Dothistroma septosporum, Mycosphaerella fijiensis, Verticillium dahliae and Zymoseptoria tritici. In these fungi, we identified 1740 gene models containing 2795 DMs obtained by an alignment-based gene prediction method. The contribution of sequencing errors to DMs was minimized by analyses of resequenced genomes to obtain a refined dataset of 924 gene models containing 1666 true DMs. The frequency of pseudogenes varied from 1% to 5% in the gene catalogues of these fungi, being the highest in the asexually reproducing fungus C. fulvum (4.9%), followed by D. septosporum (2.4%) and V. dahliae (2.1%). The majority of pseudogenes do not represent recent gene duplications, but members of multi-gene families and unitary genes. In general, there was no bias for pseudogenization of specific genes in the six fungi. Single exceptions were those encoding secreted proteins, including proteases, which appeared more frequently pseudogenized in C. fulvum than in D. septosporum. Most pseudogenes present in these two phylogenetically closely related fungi are not shared, suggesting that they are related to adaptation to a different host (tomato versus pine) and lifestyle (biotroph versus hemibiotroph).
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Affiliation(s)
- Ate van der Burgt
- Laboratory of Phytopathology, Wageningen University and Research Centre, PO Box 16, 6700 AA, Wageningen, the Netherlands; Applied Bioinformatics, Plant Research International, Wageningen University and Research Centre, PO Box 16, 6700 AA, Wageningen, the Netherlands
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Gladieux P, Ropars J, Badouin H, Branca A, Aguileta G, Vienne DM, Rodríguez de la Vega RC, Branco S, Giraud T. Fungal evolutionary genomics provides insight into the mechanisms of adaptive divergence in eukaryotes. Mol Ecol 2014; 23:753-73. [DOI: 10.1111/mec.12631] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/04/2013] [Indexed: 12/15/2022]
Affiliation(s)
- Pierre Gladieux
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
- Department of Plant and Microbial Biology University of California Berkeley CA 94720‐3102 USA
| | - Jeanne Ropars
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
| | - Hélène Badouin
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
| | - Antoine Branca
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
| | - Gabriela Aguileta
- Center for Genomic Regulation (CRG) Dr, Aiguader 88 Barcelona 08003 Spain
- Universitat Pompeu Fabra (UPF) Barcelona 08003 Spain
| | - Damien M. Vienne
- Center for Genomic Regulation (CRG) Dr, Aiguader 88 Barcelona 08003 Spain
- Universitat Pompeu Fabra (UPF) Barcelona 08003 Spain
- Laboratoire de Biométrie et Biologie Evolutive Université Lyon 1 CNRS UMR5558 Villeurbanne 69622 France
| | - Ricardo C. Rodríguez de la Vega
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
| | - Sara Branco
- Department of Plant and Microbial Biology University of California Berkeley CA 94720‐3102 USA
| | - Tatiana Giraud
- Ecologie, Systématique et Evolution UMR8079 University of Paris‐Sud Orsay 91405 France
- Ecologie, Systématique et Evolution CNRS UMR8079 Orsay 91405 France
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Leroy T, Le Cam B, Lemaire C. When virulence originates from non-agricultural hosts: new insights into plant breeding. INFECTION GENETICS AND EVOLUTION 2014; 27:521-9. [PMID: 24412509 DOI: 10.1016/j.meegid.2013.12.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/11/2013] [Accepted: 12/30/2013] [Indexed: 12/27/2022]
Abstract
Monogenic plant resistance breakdown is a model for testing evolution in action in pathogens. As a rule, plant pathologists argue that virulence - the allele that allows pathogens to overcome resistance - is due to a new mutation at the avirulence locus within the native/endemic population that infects susceptible crops. In this article, we develop an alternative and neglected scenario where a given virulence pre-exists in a non-agricultural host and might be accidentally released or introduced on the matching resistant cultivar in the field. The main difference between the two scenarios is the divergence time expected between the avirulent and the virulent populations. As a consequence, population genetic approaches such as genome scans and Approximate Bayesian Computation methods allow explicit testing of the two scenarios by timing the divergence. This review then explores the fundamental implications of this alternative scenario for plant breeding, including the invasion of virulence or the evolution of more aggressive hybrids, and proposes concrete solutions to achieve a sustainable resistance.
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Affiliation(s)
- Thibault Leroy
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France
| | - Bruno Le Cam
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France
| | - Christophe Lemaire
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France.
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Yin W, Dong S, Zhai L, Lin Y, Zheng X, Wang Y. The Phytophthora sojae Avr1d gene encodes an RxLR-dEER effector with presence and absence polymorphisms among pathogen strains. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:958-68. [PMID: 23594349 DOI: 10.1094/mpmi-02-13-0035-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Soybean root and stem rot is caused by the oomycete pathogen Phytophthora sojae. The interaction between P. sojae and soybean fits the "gene-for-gene" hypothesis. Although more than 10 P. sojae avirulence (Avr) effectors have been genetically identified, nearly half of genetically defined avr genes have been cloned. In a previous bioinformatic and global transcriptional analysis, we identified a P. sojae RxLR effector, Avr1d, which was 125 amino acids in length. Mapping data demonstrated that Avr1d presence or absence in the genome was co-segregated with the Avr1d avirulence phenotype in F2 populations. Transient expression of the Avr1d gene using co-bombardment in soybean isogenic lines revealed that this gene triggered a hypersensitive response (HR) in the presence of Rps1d. Sequencing of Avr1d genes in different P. sojae strains revealed two Avr1d alleles. Although polymorphic, the two Avr1d alleles could trigger Rps1d-mediated HR. P. sojae strains carrying either of the alleles were avirulent on Rps1d soybean lines. Avr1d was upregulated during the germinating cyst and early infection stages. Furthermore, transient expression of Avr1d in Nicotiana benthamiana suppressed BAX-induced cell death and enhanced P. capsici infection. Avr1d also suppressed effector-triggered immunity induction by associating with Avr1b and Rps1b, suggestive of a role in suppressing plant immunity.
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Affiliation(s)
- Weixiao Yin
- Nanjing Agricultural University, Nanjing, China
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Daverdin G, Rouxel T, Gout L, Aubertot JN, Fudal I, Meyer M, Parlange F, Carpezat J, Balesdent MH. Genome structure and reproductive behaviour influence the evolutionary potential of a fungal phytopathogen. PLoS Pathog 2012; 8:e1003020. [PMID: 23144620 PMCID: PMC3493481 DOI: 10.1371/journal.ppat.1003020] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 09/24/2012] [Indexed: 11/21/2022] Open
Abstract
Modern agriculture favours the selection and spread of novel plant diseases. Furthermore, crop genetic resistance against pathogens is often rendered ineffective within a few years of its commercial deployment. Leptosphaeria maculans, the cause of phoma stem canker of oilseed rape, develops gene-for-gene interactions with its host plant, and has a high evolutionary potential to render ineffective novel sources of resistance in crops. Here, we established a four-year field experiment to monitor the evolution of populations confronted with the newly released Rlm7 resistance and to investigate the nature of the mutations responsible for virulence against Rlm7. A total of 2551 fungal isolates were collected from experimental crops of a Rlm7 cultivar or a cultivar without Rlm7. All isolates were phenotyped for virulence and a subset was genotyped with neutral genetic markers. Virulent isolates were investigated for molecular events at the AvrLm4-7 locus. Whilst virulent isolates were not found in neighbouring crops, their frequency had reached 36% in the experimental field after four years. An extreme diversity of independent molecular events leading to virulence was identified in populations, with large-scale Repeat Induced Point mutations or complete deletion of AvrLm4-7 being the most frequent. Our data suggest that increased mutability of fungal genes involved in the interactions with plants is directly related to their genomic environment and reproductive system. Thus, rapid allelic diversification of avirulence genes can be generated in L. maculans populations in a single field provided that large population sizes and sexual reproduction are favoured by agricultural practices.
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Affiliation(s)
| | - Thierry Rouxel
- INRA, UR 1290 Bioger, Campus AgroParisTech, Thiverval-Grignon, France
| | - Lilian Gout
- INRA, UR 1290 Bioger, Campus AgroParisTech, Thiverval-Grignon, France
- AgroParisTech, Campus AgroParisTech, Thiverval-Grignon, France
| | | | - Isabelle Fudal
- INRA, UR 1290 Bioger, Campus AgroParisTech, Thiverval-Grignon, France
| | - Michel Meyer
- INRA, UR 1290 Bioger, Campus AgroParisTech, Thiverval-Grignon, France
| | - Francis Parlange
- INRA, UR 1290 Bioger, Campus AgroParisTech, Thiverval-Grignon, France
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Stergiopoulos I, Collemare J, Mehrabi R, De Wit PJGM. Phytotoxic secondary metabolites and peptides produced by plant pathogenic Dothideomycete fungi. FEMS Microbiol Rev 2012; 37:67-93. [PMID: 22931103 DOI: 10.1111/j.1574-6976.2012.00349.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/01/2012] [Accepted: 07/19/2012] [Indexed: 01/25/2023] Open
Abstract
Many necrotrophic plant pathogenic fungi belonging to the class of Dothideomycetes produce phytotoxic metabolites and peptides that are usually required for pathogenicity. Phytotoxins that affect a broad range of plant species are known as non-host-specific toxins (non-HSTs), whereas HSTs affect only a particular plant species or more often genotypes of that species. For pathogens producing HSTs, pathogenicity and host specificity are largely defined by the ability to produce the toxin, while plant susceptibility is dependent on the presence of the toxin target. Non-HSTs are not the main determinants of pathogenicity but contribute to virulence of the producing pathogen. Dothideomycetes are remarkable for the production of toxins, particularly HSTs because they are the only fungal species known so far to produce them. The synthesis, regulation, and mechanisms of action of the most important HSTs and non-HSTs will be discussed. Studies on the mode of action of HSTs have highlighted the induction of programed cell death (PCD) as an important mechanism. We discuss HST-induced PCD and the plant hypersensitive response upon recognition of avirulence factors that share common pathways. In this respect, although nucleotide-binding-site-leucine-rich repeat types of resistance proteins mediate resistance against biotrophs, they can also contribute to susceptibility toward necrotrophs.
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Van de Wouw AP, Howlett BJ. Estimating frequencies of virulent isolates in field populations of a plant pathogenic fungus, Leptosphaeria maculans, using high-throughput pyrosequencing. J Appl Microbiol 2012; 113:1145-53. [PMID: 22830361 DOI: 10.1111/j.1365-2672.2012.05413.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 07/18/2012] [Accepted: 07/19/2012] [Indexed: 11/27/2022]
Abstract
AIM To develop a pyrosequencing assay to monitor the frequency of alleles of an avirulence gene, AvrLm4, in populations of sexual spores of Leptosphaeria maculans, a fungal pathogen of canola (Brassica napus). METHODS AND RESULTS The predominant mutation in AvrLm4 responsible for virulence to the corresponding resistance gene, Rlm4, is a single nucleotide polymorphism (SNP) at base 358. Pyrosequencing primers were designed to amplify a 90-bp region that included this SNP. The assay was developed and validated by analysing the frequency of AvrLm4 in isolate mixtures of different proportions. Furthermore, the frequency of avrLm4 (virulence allele) determined by pyrosequencing of populations of sexual spores was consistent with the frequency of avrLm4 determined by Sanger sequencing of the entire AvrLm4 gene from single isolates cultured from the same stubble. CONCLUSION This high-throughput assay can play an important role in predicting the risk of resistance breakdown in crops. SIGNIFICANCE AND IMPACT OF THE STUDY Similar assays can be applied to monitor frequencies of fungicide resistance in pathogens of crops and to assay diversity in microbial soil communities such as in soil samples from bat caves where white-nose syndrome has been detected.
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Affiliation(s)
- A P Van de Wouw
- School of Botany, University of Melbourne, Melbourne, Vic., Australia.
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Stergiopoulos I, Kourmpetis YAI, Slot JC, Bakker FT, De Wit PJGM, Rokas A. In silico characterization and molecular evolutionary analysis of a novel superfamily of fungal effector proteins. Mol Biol Evol 2012; 29:3371-84. [PMID: 22628532 DOI: 10.1093/molbev/mss143] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Most fungal plant pathogens secrete effector proteins during pathogenesis to manipulate their host's defense and promote disease. These are so highly diverse in sequence and distribution, they are essentially considered as species-specific. However, we have recently shown the presence of homologous effectors in fungal species of the Dothideomycetes class. One such example is Ecp2, an effector originally described in the tomato pathogen Cladosporium fulvum but later detected in the plant pathogenic fungi Mycosphaerella fijiensis and Mycosphaerella graminicola as well. Here, using in silico sequence-similarity searches against a database of 135 fungal genomes and GenBank, we extend our queries for homologs of Ecp2 to the fungal kingdom and beyond, and further study their history of diversification. Our analyses show that Ecp2 homologs are members of an ancient and widely distributed superfamily of putative fungal effectors, which we term Hce2 for Homologs of C. fulvum Ecp2. Molecular evolutionary analyses show that the superfamily originated and diversified within the fungal kingdom, experiencing multiple lineage-specific expansions and losses that are consistent with the birth-and-death model of gene family evolution. Newly formed paralogs appear to be subject to diversification early after gene duplication events, whereas at later stages purifying selection acts to preserve diversity and the newly evolved putative functions. Some members of the Hce2 superfamily are fused to fungal Glycoside Hydrolase family 18 chitinases that show high similarity to the Zymocin killer toxin from the dairy yeast Kluyveromyces lactis, suggesting an analogous role in antagonistic interactions. The observed high rates of gene duplication and loss in the Hce2 superfamily, combined with diversification in both sequence and possibly functions within and between species, suggest that Hce2s are involved in adaptation to stresses and new ecological niches. Such findings address the need to rationalize effector biology and evolution beyond the perspective of solely host-microbe interactions.
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Tan KC, Ferguson-Hunt M, Rybak K, Waters ODC, Stanley WA, Bond CS, Stukenbrock EH, Friesen TL, Faris JD, McDonald BA, Oliver RP. Quantitative variation in effector activity of ToxA isoforms from Stagonospora nodorum and Pyrenophora tritici-repentis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:515-22. [PMID: 22250581 DOI: 10.1094/mpmi-10-11-0273] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
ToxA is a proteinaceous necrotrophic effector produced by Stagonospora nodorum and Pyrenophora tritici-repentis. In this study, all eight mature isoforms of the ToxA protein were purified and compared. Circular dichroism spectra indicated that all isoforms were structurally intact and had indistinguishable secondary structural features. ToxA isoforms were infiltrated into wheat lines that carry the sensitivity gene Tsn1. It was observed that different wheat lines carrying identical Tsn1 alleles varied in sensitivity to ToxA. All ToxA isoforms induced necrosis when introduced into any Tsn1 wheat line but we observed quantitative variation in effector activity, with the least-active version found in isolates of P. tritici-repentis. Pathogen sporulation increased with higher doses of ToxA. The isoforms that induced the most rapid necrosis also induced the most sporulation, indicating that pathogen fitness is affected by differences in ToxA activity. We show that differences in toxin activity encoded by a single gene can contribute to the quantitative inheritance of necrotrophic virulence. Our findings support the hypothesis that the variation at ToxA results from selection that favors increased toxin activity.
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Affiliation(s)
- Kar-Chun Tan
- Environment and Agriculture, Curtin University, Bentley WA 6102, Australia
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Cui L, Yin W, Dong S, Wang Y. Analysis of polymorphism and transcription of the effector gene Avr1b in Phytophthora sojae isolates from China virulent to Rps1b. MOLECULAR PLANT PATHOLOGY 2012; 13:114-22. [PMID: 21726400 PMCID: PMC6638858 DOI: 10.1111/j.1364-3703.2011.00733.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The effector gene Avr1b-1 of Phytophthora sojae determines the efficacy of the resistance gene Rps1b in soybean. The sequences of the Avr1b-1 locus in 34 Chinese isolates of P. sojae were obtained and analysed by polymerase chain reaction (PCR) and inverse PCR. Four different alleles and a complete deletion mutation of the Avr1b-1 gene were identified. Molecular analysis of the deletion breakpoints in the Avr1b-1 locus revealed that an 8-kb DNA sequence containing Avr1b-1 was deleted and a 12.7-kb DNA sequence was inserted at the same locus. A truncated transposase gene was found and five transposable elements were predicted in the inserted sequence, suggesting that the deletion of Avr1b-1 might be attributed to transposon movement. The transcription of Avr1b-1 was analysed in virulent isolates containing four alleles of Avr1b-1 by real-time reverse transcription-PCR. In all virulent isolates, only those isolates containing the second allele transcripted Avr1b-1.
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Affiliation(s)
- Linkai Cui
- College of Plant Protection, Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing 210095, China
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Cabral A, Stassen JHM, Seidl MF, Bautor J, Parker JE, Van den Ackerveken G. Identification of Hyaloperonospora arabidopsidis transcript sequences expressed during infection reveals isolate-specific effectors. PLoS One 2011; 6:e19328. [PMID: 21573066 PMCID: PMC3090399 DOI: 10.1371/journal.pone.0019328] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 03/25/2011] [Indexed: 12/25/2022] Open
Abstract
Biotrophic plant pathogens secrete effector proteins that are important for infection of the host. The aim of this study was to identify effectors of the downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa) that are expressed during infection of its natural host Arabidopsis thaliana. Infection-related transcripts were identified from Expressed Sequence Tags (ESTs) derived from leaves of the susceptible Arabidopsis Ws eds1-1 mutant inoculated with the highly virulent Hpa isolate Waco9. Assembly of 6364 ESTs yielded 3729 unigenes, of which 2164 were Hpa-derived. From the translated Hpa unigenes, 198 predicted secreted proteins were identified. Of these, 75 were found to be Hpa-specific and six isolate Waco9-specific. Among 42 putative effectors identified there were three Elicitin-like proteins, 16 Cysteine-rich proteins and 18 host-translocated RXLR effectors. Sequencing of alleles in different Hpa isolates revealed that five RXLR genes show signatures of diversifying selection. Thus, EST analysis of Hpa-infected Arabidopsis is proving to be a powerful method for identifying pathogen effector candidates expressed during infection. Delivery of the Waco9-specific protein RXLR29 in planta revealed that this effector can suppress PAMP-triggered immunity and enhance disease susceptibility. We propose that differences in host colonization can be conditioned by isolate-specific effectors.
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Affiliation(s)
- Adriana Cabral
- Department of Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Joost H. M. Stassen
- Department of Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Michael F. Seidl
- Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands
- Centre for BioSystems Genomics (CBSG), Wageningen, The Netherlands
| | - Jaqueline Bautor
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jane E. Parker
- Department of Plant-Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Guido Van den Ackerveken
- Department of Plant-Microbe Interactions, Department of Biology, Utrecht University, Utrecht, The Netherlands
- Centre for BioSystems Genomics (CBSG), Wageningen, The Netherlands
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