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Calia G, Cestaro A, Schuler H, Janik K, Donati C, Moser M, Bottini S. Definition of the effector landscape across 13 phytoplasma proteomes with LEAPH and EffectorComb. NAR Genom Bioinform 2024; 6:lqae087. [PMID: 39081684 PMCID: PMC11287381 DOI: 10.1093/nargab/lqae087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 06/24/2024] [Accepted: 07/16/2024] [Indexed: 08/02/2024] Open
Abstract
'Candidatus Phytoplasma' genus, a group of fastidious phloem-restricted bacteria, can infect a wide variety of both ornamental and agro-economically important plants. Phytoplasmas secrete effector proteins responsible for the symptoms associated with the disease. Identifying and characterizing these proteins is of prime importance for expanding our knowledge of the molecular bases of the disease. We faced the challenge of identifying phytoplasma's effectors by developing LEAPH, a machine learning ensemble predictor composed of four models. LEAPH was trained on 479 proteins from 53 phytoplasma species, described by 30 features. LEAPH achieved 97.49% accuracy, 95.26% precision and 98.37% recall, ensuring a low false-positive rate and outperforming available state-of-the-art methods. The application of LEAPH to 13 phytoplasma proteomes yields a comprehensive landscape of 2089 putative pathogenicity proteins. We identified three classes according to different secretion models: 'classical', 'classical-like' and 'non-classical'. Importantly, LEAPH identified 15 out of 17 known experimentally validated effectors belonging to the three classes. Furthermore, to help the selection of novel candidates for biological validation, we applied the Self-Organizing Maps algorithm and developed a Shiny app called EffectorComb. LEAPH and the EffectorComb app can be used to boost the characterization of putative effectors at both computational and experimental levels, and can be employed in other phytopathological models.
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Affiliation(s)
- Giulia Calia
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, 39100 Bolzano, Italy
- Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all’Adige, Italy
- INRAE, Institut Sophia Agrobiotech, Université Côte d’Azur, CNRS, 06903 Sophia-Antipolis, France
| | - Alessandro Cestaro
- Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all’Adige, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), 70126 Bari, Italy
| | - Hannes Schuler
- Faculty of Agricultural, Environmental and Food Sciences, Free University of Bolzano, 39100 Bolzano, Italy
- Competence Centre for Plant Health, Free University of Bolzano, 39100 Bolzano, Italy
| | - Katrin Janik
- Institute for Plant Health, Molecular Biology and Microbiology, Laimburg Research Centre, 47141 Pfatten-Vadena, Italy
| | - Claudio Donati
- Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all’Adige, Italy
| | - Mirko Moser
- Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all’Adige, Italy
| | - Silvia Bottini
- INRAE, Institut Sophia Agrobiotech, Université Côte d’Azur, CNRS, 06903 Sophia-Antipolis, France
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2
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Rogers A, Jaiswal N, Roggenkamp E, Kim HS, MacCready JS, Chilvers MI, Scofield SR, Iyer-Pascuzzi AS, Helm M. Genome-Informed Trophic Classification and Functional Characterization of Virulence Proteins from the Maize Tar Spot Pathogen Phyllachora maydis. PHYTOPATHOLOGY 2024; 114:1940-1949. [PMID: 38717940 DOI: 10.1094/phyto-01-24-0037-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Phyllachora maydis is an ascomycete foliar fungal pathogen and the causal agent of tar spot in maize. Although P. maydis is considered an economically important foliar pathogen of maize, our general knowledge of the trophic lifestyle and functional role of effector proteins from this fungal pathogen remains limited. Here, we utilized a genome-informed approach to predict the trophic lifestyle of P. maydis and functionally characterized a subset of candidate effectors from this fungal pathogen. Leveraging the most recent P. maydis genome annotation and the CATAStrophy pipeline, we show that this fungal pathogen encodes a predicted carbohydrate-active enzymes (CAZymes) repertoire consistent with that of biotrophs. To investigate fungal pathogenicity, we selected 18 candidate effector proteins that were previously shown to be expressed during primary disease development. We assessed whether these putative effectors share predicted structural similarity with other characterized fungal effectors and determined whether any suppress plant immune responses. Using AlphaFold2 and Foldseek, we showed that one candidate effector, PM02_g1115, adopts a predicted protein structure similar to that of an effector from Verticillium dahlia. Furthermore, transient expression of candidate effector-fluorescent protein fusions in Nicotiana benthamiana revealed two putative effectors, PM02_g378 and PM02_g2610, accumulated predominantly in the cytosol, and three candidate effectors, PM02_g1115, PM02_g7882, and PM02_g8240, consistently attenuated chitin-mediated reactive oxygen species production. Collectively, the results presented herein provide insights into the predicted trophic lifestyle and putative functions of effectors from P. maydis and will likely stimulate continued research to elucidate the molecular mechanisms used by P. maydis to induce tar spot.
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Affiliation(s)
- Abigail Rogers
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907
| | - Namrata Jaiswal
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
| | - Emily Roggenkamp
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Hye-Seon Kim
- U.S. Department of Agriculture-Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604
| | - Joshua S MacCready
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Martin I Chilvers
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Steven R Scofield
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
| | | | - Matthew Helm
- Crop Production and Pest Control Research Unit, U.S. Department of Agriculture-Agricultural Research Service, West Lafayette, IN 47907
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3
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Cao P, Shi H, Zhang S, Chen J, Wang R, Liu P, Zhu Y, An Y, Zhang M. A robust high-throughput functional screening assay for plant pathogen effectors using the TMV-GFP vector. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 119:617-631. [PMID: 38647454 DOI: 10.1111/tpj.16774] [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: 11/19/2023] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
Uncovering the function of phytopathogen effectors is crucial for understanding mechanisms of pathogen pathogenicity and for improving our ability to protect plants from diseases. An increasing number of effectors have been predicted in various plant pathogens. Functional characterization of these effectors has become a major focus in the study of plant-pathogen interactions. In this study, we designed a novel screening system that combines the TMV (tobacco mosaic virus)-GFP vector and Agrobacterium-mediated transient expression in the model plant Nicotiana benthamiana. This system enables the rapid identification of effectors that interfere with plant immunity. The biological function of these effectors can be easily evaluated by observing the GFP fluorescence signal using a UV lamp within just a few days. To evaluate the TMV-GFP system, we initially tested it with well-described virulence and avirulence type III effectors from the bacterial pathogen Ralstonia solanacearum. After proving the accuracy and efficiency of the TMV-GFP system, we successfully screened a novel virulence effector, RipS1, using this approach. Furthermore, using the TMV-GFP system, we reproduced consistent results with previously known cytoplasmic effectors from a diverse array of pathogens. Additionally, we demonstrated the effectiveness of the TMV-GFP system in identifying apoplastic effectors. The easy operation, time-saving nature, broad effectiveness, and low technical requirements of the TMV-GFP system make it a promising approach for high-throughput screening of effectors with immune interference activity from various pathogens.
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Affiliation(s)
- Peng Cao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Haotian Shi
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuangxi Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Jialan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Rongbo Wang
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Peiqing Liu
- Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Yingfang Zhu
- State Key Laboratory of Crop Stress Adaptation and Improvement, Key Laboratory of Cotton Biology, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Yuyan An
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
| | - Meixiang Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, China
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4
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Zhao Y, Zheng X, Tabima JF, Zhu S, Søndreli KL, Hundley H, Bauer D, Barry K, Zhang Y, Schmutz J, Wang Y, LeBoldus JM, Xiong Q. Secreted Effector Proteins of Poplar Leaf Spot and Stem Canker Pathogen Sphaerulina musiva Manipulate Plant Immunity and Contribute to Virulence in Diverse Ways. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:779-795. [PMID: 37551980 DOI: 10.1094/mpmi-07-23-0091-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Fungal effectors play critical roles in manipulating plant immune responses and promoting colonization. Sphaerulina musiva is a heterothallic ascomycete fungus that causes Septoria leaf spot and stem canker disease in poplar (Populus spp.) plantations. This disease can result in premature defoliation, branch and stem breakage, increased mortality, and plantation failure. However, little is known about the interaction between S. musiva and poplar. Previous work predicted 142 candidate secreted effector proteins in S. musiva (SmCSEPs), 19 of which were selected for further functional characterization in this study. SmCSEP3 induced plant cell death in Nicotiana benthamiana, while 8 out of 19 tested SmCSEPs suppressed cell death. The signal peptides of these eight SmCSEPs exhibited secretory activity in a yeast signal sequence trap assay. Confocal microscopy revealed that four of these eight SmCSEPs target both the cytoplasm and the nucleus, whereas four predominantly localize to discrete punctate structures. Pathogen challenge assays in N. benthamiana demonstrated that the transient expression of six SmCSEPs promoted Fusarium proliferatum infection. The expression of these six SmCSEP genes were induced during infection. SmCSEP2, SmCSEP13, and SmCSEP25 suppressed chitin-triggered reactive oxygen species burst and callose deposition in N. benthamiana. The candidate secreted effector proteins of S. musiva target multiple compartments in the plant cell and modulate different pattern-triggered immunity pathways. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2023.
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Affiliation(s)
- Yao Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210095, China
| | - Xinyue Zheng
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Javier F Tabima
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
- Department of Forest Engineering, Resources and Management, College of Forestry, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Sheng Zhu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Kelsey L Søndreli
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Hope Hundley
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Diane Bauer
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Kerrie Barry
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Yaxin Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jeremy Schmutz
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S.A
| | - Yuanchao Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210095, China
| | - Jared M LeBoldus
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
- Department of Biology, Clark University, Worcester, MA 01610, U.S.A
| | - Qin Xiong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
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5
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Farias KS, Ferreira MM, Amaral GV, Zugaib M, Santos AS, Gomes FP, Rezende RP, Gramacho KP, Aguiar ERGR, Pirovani CP. BASIDIN as a New Protein Effector of the Phytopathogen Causing Witche's Broom Disease in Cocoa. Int J Mol Sci 2023; 24:11714. [PMID: 37511472 PMCID: PMC10380501 DOI: 10.3390/ijms241411714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
The fungus Moniliophthora perniciosa secretes protein effectors that manipulate the physiology of the host plant, but few effectors of this fungus have had their functions confirmed. We performed functional characterization of a promising candidate effector of M. perniciosa. The inoculation of rBASIDIN at 4 µmol L-1 in the mesophyll of leaflets of Solanum lycopersicum caused symptoms of shriveling within 6 h without the presence of necrosis. However, when sprayed on the plant at a concentration of 11 µmol L-1, it caused wilting symptoms only 2 h after application, followed by necrosis and cell death at 48 h. rBASIDIN applied to Theobroma cacao leaves at the same concentration caused milder symptoms. rBASIDIN caused hydrogen peroxide production in leaf tissue, damaging the leaf membrane and negatively affecting the photosynthetic rate of Solanum lycopersicum plants. Phylogenetic analysis indicated that BASIDIN has orthologs in other phytopathogenic basidiomycetes. Analysis of the transcripts revealed that BASIDIN and its orthologs are expressed in different fungal species, suggesting that this protein is differentially regulated in these basidiomycetes. Therefore, the results of applying BASIDIN allow the inference that it is an effector of the fungus M. perniciosa, with a strong potential to interfere in the defense system of the host plant.
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Affiliation(s)
- Keilane Silva Farias
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Monaliza Macêdo Ferreira
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Geiseane Veloso Amaral
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Maria Zugaib
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Ariana Silva Santos
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Fábio Pinto Gomes
- Fisiologia Vegetal, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Rachel Passos Rezende
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Karina Peres Gramacho
- Comissão Executiva do Plano da Lavoura Cacaueira, Centro de Pesquisas do Cacau-MAPA, Laboratório de Fitopatologia Molecular, km 22 Rodovia Ilhéus Itabuna, Ilhéus 45600-970, Bahia, Brazil
| | - Eric Roberto Guimarães Rocha Aguiar
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
| | - Carlos Priminho Pirovani
- Centro de Biotecnologia e Genética, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Ilhéus-Itabuna, km 16, Ilhéus 45662-900, Bahia, Brazil
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6
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Kumar A, Fitoussi N, Sanadhya P, Sichov N, Bucki P, Bornstein M, Belausuv E, Brown Miyara S. Two Candidate Meloidogyne javanica Effector Genes, MjShKT and MjPUT3: A Functional Investigation of Their Roles in Regulating Nematode Parasitism. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:79-94. [PMID: 36324054 DOI: 10.1094/mpmi-10-22-0212-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
During parasitism, root-knot nematode Meloidogyne spp. inject molecules termed effectors that have multifunctional roles in construction and maintenance of nematode feeding sites. As an outcome of transcriptomic analysis of Meloidogyne javanica, we identified and characterized two differentially expressed genes encoding the predicted proteins MjShKT, carrying a Stichodactyla toxin (ShKT) domain, and MjPUT3, carrying a ground-like domain, both expressed during nematode parasitism of the tomato plant. Fluorescence in-situ hybridization revealed expression of MjShKT and MjPUT3 in the dorsal esophageal glands, suggesting their injection into host cells. MjShKT expression was upregulated during the parasitic life stages, to a maximum at the mature female stage, whereas MjPUT3 expression increased in third- to fourth-stage juveniles. Subcellular in-planta localization of MjShKT and MjPUT3 using a fused fluorescence marker indicated MjShKT co-occurrence with the endoplasmic reticulum, the perinuclear endoplasmatic reticulum, and the Golgi organelle markers, while MjPUT3 localized, to some extent, within the endoplasmatic reticulum and was clearly observed within the nucleoplasm. MjShKT inhibited programmed cell death induced by overexpression of MAPKKKα and Gpa2/RBP-1. Overexpression of MjShKT in tomato hairy roots allowed an increase in nematode reproduction, as indicated by the high number of eggs produced on roots overexpressing MjShKT. Roots overexpressing MjPUT3 were characterized by enhanced root growth, with no effect on nematode development on those roots. Investigation of the two candidate effectors suggested that MjShKT is mainly involved in manipulating the plant effector-triggered immune response toward establishment and maintenance of active feeding sites, whereas MjPUT3 might modulate roots morphology in favor of nematode fitness in the host roots. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Anil Kumar
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Nathalia Fitoussi
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
- Department of Plant Pathology and Microbiology, the Robert H. Smith Faculty of Agriculture, Food and Environment, the Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Payal Sanadhya
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Natalia Sichov
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Patricia Bucki
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
| | - Menachem Bornstein
- Department of Plant Pathology and Weed Research, ARO, Volcani Center, Bet Dagan 50250, Israel
| | - Eduard Belausuv
- Department of Plant Sciences, ARO, Volcani Center, Bet Dagan 50250, Israel
| | - Sigal Brown Miyara
- Department of Entomology, Nematology and Chemistry units, Agricultural Research Organization (ARO), Volcani Center, Bet Dagan 50250, Israel
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7
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Montenegro Alonso AP, Bakkeren G. Transfection of Barley Leaf Protoplasts with a Fluorescently Tagged Fungal Effector for In Planta Localization Studies in Barley. Methods Mol Biol 2023; 2659:83-93. [PMID: 37249887 DOI: 10.1007/978-1-0716-3159-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The isolation and transfection of protoplasts from plant leaves have been routinely used for transient expression and functional studies in model plants. However, current approaches to characterize pathogen effector molecules in a cereal host are inefficient and technically challenging. In this chapter, we describe a protocol to isolate and transfect barley mesophyll protoplasts with a fluorescently tagged fungal effector of the barley smut pathogen Ustilago hordei. Tagging of a fungal effector with a fluorescent protein and tracking its localization in cells of its natural host provides insight into its putative in planta localization and helps to narrow down the location of putative host interactors.
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Affiliation(s)
- Ana Priscilla Montenegro Alonso
- Department of Botany, University of British Columbia, Vancouver, BC, Canada
- Saskatoon Research and Development Centre, Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
| | - Guus Bakkeren
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada.
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A Putative Effector LtCSEP1 from Lasiodiplodia theobromae Inhibits BAX-Triggered Cell Death and Suppresses Immunity Responses in Nicotiana benthamiana. PLANTS 2022; 11:plants11111462. [PMID: 35684232 PMCID: PMC9182993 DOI: 10.3390/plants11111462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022]
Abstract
Lasiodiplodia theobromae is a causal agent of grapevine trunk disease, and it poses a significant threat to the grape industry worldwide. Fungal effectors play an essential role in the interaction between plants and pathogens. However, few studies have been conducted to understand the functions of individual effectors in L. theobromae. In this study, we identified and characterized a candidate secreted effector protein, LtCSEP1, in L. theobromae. Gene expression analysis suggested that transcription of LtCSEP1 in L. theobromae was induced at the early infection stages in the grapevine. Yeast secretion assay revealed that LtCSEP1 contains a functional signal peptide. Transient expression of LtCSEP1 in Nicotiana benthamiana suppresses BAX-trigged cell death and significantly inhibits the flg22-induced PTI-associated gene expression. Furthermore, the ectopic expression of LtCSEP1 in N. benthamiana enhanced disease susceptibility to L. theobromae by downregulating the defense-related genes. These results demonstrated that LtCSEP1 is a potential effector of L. theobromae, which contributes to suppressing the plant’s defenses.
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Kang S, Kim KT, Choi J, Kim H, Cheong K, Bandara A, Lee YH. Genomics and Informatics, Conjoined Tools Vital for Understanding and Protecting Plant Health. PHYTOPATHOLOGY 2022; 112:981-995. [PMID: 34889667 DOI: 10.1094/phyto-10-21-0418-rvw] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Genomics' impact on crop production continuously expands. The number of sequenced plant and microbial species and strains representing diverse populations of individual species rapidly increases thanks to the advent of next-generation sequencing technologies. Their genomic blueprints revealed candidate genes involved in various functions and processes crucial for crop health and helped in understanding how the sequenced organisms have evolved at the genome level. Functional genomics quickly translates these blueprints into a detailed mechanistic understanding of how such functions and processes work and are regulated; this understanding guides and empowers efforts to protect crops from diverse biotic and abiotic threats. Metagenome analyses help identify candidate microbes crucial for crop health and uncover how microbial communities associated with crop production respond to environmental conditions and cultural practices, presenting opportunities to enhance crop health by judiciously configuring microbial communities. Efficient conversion of disparate types of massive genomics data into actionable knowledge requires a robust informatics infrastructure supporting data preservation, analysis, and sharing. This review starts with an overview of how genomics came about and has quickly transformed life science. We illuminate how genomics and informatics can be applied to investigate various crop health-related problems using selected studies. We end the review by noting why community empowerment via crowdsourcing is crucial to harnessing genomics to protect global food and nutrition security without continuously expanding the environmental footprint of crop production.
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Affiliation(s)
- Seogchan Kang
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Ki-Tae Kim
- Department of Agricultural Life Science, Sunchon National University, Suncheon 57922, Korea
| | - Jaeyoung Choi
- Korea Institute of Science and Technology Gangneung Institute of Natural Products, Gangneung 25451, Korea
| | - Hyun Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
| | - Kyeongchae Cheong
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
| | - Ananda Bandara
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA 16802, U.S.A
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea
- Plant Immunity Research Center, Seoul National University, Seoul 08826, Korea
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10
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Current perspectives on the beneficial effects of soybean isoflavones and their metabolites on plants. Food Sci Biotechnol 2022; 31:515-526. [PMID: 35529690 PMCID: PMC9033921 DOI: 10.1007/s10068-022-01070-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 03/04/2022] [Accepted: 03/21/2022] [Indexed: 11/04/2022] Open
Abstract
Soybeans have traditionally been a staple part of the human diet being highly rich in protein and lipid content. In an addition to the high nutritional components, soybeans have several functional components, like isoflavones, saponins, lecithin, and oligosaccharides. Soybeans emerge as a healthy functional food option. Isoflavones are most notable functional component of soybeans, exhibiting antioxidant activity while preventing plant-related diseases (e.g., antimicrobial and antiherbivore activities) and having positive effects on the life quality of plants. Isoflavones are thus sometimes referred to as phytochemicals. The latest research trends evince substantial interest in the biological efficacy of isoflavones in the human body as well as in plants and their related mechanisms. However, there is little information on the relationship between isoflavones and plants than beneficial human effects. This review discusses what is known about the physiological communication (transport and secretion) between isoflavones and plants, especially in soybeans.
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11
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Stevens DM, Tang A, Coaker G. A Genetic Toolkit for Investigating Clavibacter Species: Markerless Deletion, Permissive Site Identification, and an Integrative Plasmid. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1336-1345. [PMID: 34890250 DOI: 10.1094/mpmi-07-21-0171-ta] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The development of knockout mutants and expression variants are critical for understanding genotype-phenotype relationships. However, advances in these techniques in gram-positive actinobacteria have stagnated over the last decade. Actinobacteria in the Clavibacter genus are composed of diverse crop pathogens that cause a variety of wilt and cankering diseases. Here, we present a suite of tools for genetic manipulation in the tomato pathogen Clavibacter michiganensis including a markerless deletion system, an integrative plasmid, and an R package for identification of permissive sites for plasmid integration. The vector pSelAct-KO is a recombination-based, markerless knockout system that uses dual selection to engineer seamless deletions of a region of interest, providing opportunities for repeated higher-order genetic knockouts. The efficacy of pSelAct-KO was demonstrated in C. michiganensis and was confirmed using whole-genome sequencing. We developed permissR, an R package to identify permissive sites for chromosomal integration, which can be used in conjunction with pSelAct-Express, a nonreplicating integrative plasmid that enables recombination into a permissive genomic location. Expression of enhanced green fluorescent protein by pSelAct-Express was verified in two candidate permissive regions predicted by permissR in C. michiganensis. These molecular tools are essential advances for investigating gram-positive actinobacteria, particularly for important pathogens in the Clavibacter genus.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Danielle M Stevens
- Integrative Genetics and Genomics Graduate Group, University of California, Davis, Davis, CA 95616, U.S.A
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, U.S.A
| | - Andrea Tang
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, U.S.A
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, Davis, CA 95616, U.S.A
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12
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Achari SR, Edwards J, Mann RC, Kaur JK, Sawbridge T, Summerell BA. Comparative transcriptomic analysis of races 1, 2, 5 and 6 of Fusarium oxysporum f.sp. pisi in a susceptible pea host identifies differential pathogenicity profiles. BMC Genomics 2021; 22:734. [PMID: 34627148 PMCID: PMC8502283 DOI: 10.1186/s12864-021-08033-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 09/23/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The fungal pathogen Fusarium oxysporum f.sp. pisi (Fop) causes Fusarium wilt in peas. There are four races globally: 1, 2, 5 and 6 and all of these races are present in Australia. Molecular infection mechanisms have been studied in a few other F. oxysporum formae speciales; however, there has been no transcriptomic Fop-pea pathosystem study. RESULTS A transcriptomic study was carried out to understand the molecular pathogenicity differences between the races. Transcriptome analysis at 20 days post-inoculation revealed differences in the differentially expressed genes (DEGs) in the Fop races potentially involved in fungal pathogenicity variations. Most of the DEGs in all the races were engaged in transportation, metabolism, oxidation-reduction, translation, biosynthetic processes, signal transduction, proteolysis, among others. Race 5 expressed the most virulence-associated genes. Most genes encoding for plant cell wall degrading enzymes, CAZymes and effector-like proteins were expressed in race 2. Race 6 expressed the least number of genes at this time point. CONCLUSION Fop races deploy various factors and complex strategies to mitigate host defences to facilitate colonisation. This investigation provides an overview of the putative pathogenicity genes in different Fop races during the necrotrophic stage of infection. These genes need to be functionally characterised to confirm their pathogenicity/virulence roles and the race-specific genes can be further explored for molecular characterisation.
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Affiliation(s)
- Saidi R Achari
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia.
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia.
| | - Jacqueline Edwards
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia
| | - Ross C Mann
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
| | - Jatinder K Kaur
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
| | - Tim Sawbridge
- AgriBio, Agriculture Victoria Research, DJPR, Bundoora, Victoria, Australia
- School of Applied Systems Biology, La Trobe University, Bundoora, Victoria, Australia
| | - Brett A Summerell
- Australian Institute of Botanical Science, Royal Botanic Gardens & Domain Trust, Sydney, NSW, Australia
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13
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Dalio RJD, Litholdo CG, Arena G, Magalhães D, Machado MA. Contribution of Omics and Systems Biology to Plant Biotechnology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1346:171-188. [DOI: 10.1007/978-3-030-80352-0_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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14
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Arroyo-Velez N, González-Fuente M, Peeters N, Lauber E, Noël LD. From effectors to effectomes: Are functional studies of individual effectors enough to decipher plant pathogen infectious strategies? PLoS Pathog 2020; 16:e1009059. [PMID: 33270803 PMCID: PMC7714205 DOI: 10.1371/journal.ppat.1009059] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Noe Arroyo-Velez
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Nemo Peeters
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Laurent D. Noël
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
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15
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Kanja C, Hammond‐Kosack KE. Proteinaceous effector discovery and characterization in filamentous plant pathogens. MOLECULAR PLANT PATHOLOGY 2020; 21:1353-1376. [PMID: 32767620 PMCID: PMC7488470 DOI: 10.1111/mpp.12980] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/03/2020] [Accepted: 07/05/2020] [Indexed: 05/26/2023]
Abstract
The complicated interplay of plant-pathogen interactions occurs on multiple levels as pathogens evolve to constantly evade the immune responses of their hosts. Many economically important crops fall victim to filamentous pathogens that produce small proteins called effectors to manipulate the host and aid infection/colonization. Understanding the effector repertoires of pathogens is facilitating an increased understanding of the molecular mechanisms underlying virulence as well as guiding the development of disease control strategies. The purpose of this review is to give a chronological perspective on the evolution of the methodologies used in effector discovery from physical isolation and in silico predictions, to functional characterization of the effectors of filamentous plant pathogens and identification of their host targets.
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Affiliation(s)
- Claire Kanja
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- School of BiosciencesUniversity of NottinghamNottinghamUK
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16
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Zhang Y, Wei J, Qi Y, Li J, Amin R, Yang W, Liu D. Predicating the Effector Proteins Secreted by Puccinia triticina Through Transcriptomic Analysis and Multiple Prediction Approaches. Front Microbiol 2020; 11:538032. [PMID: 33072007 PMCID: PMC7536266 DOI: 10.3389/fmicb.2020.538032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/26/2020] [Indexed: 11/17/2022] Open
Abstract
Wheat leaf rust caused by Puccinia triticina is one of the most common and serious diseases in wheat production. The constantly changing pathogens overcome the plant resistance to P. triticina. Plant pathogens secrete effector proteins that alter the structure of the host cell, interfere plant defenses, or modify the physiology of plant cells. Therefore, the identification of effector proteins is critical to reveal the pathogenic mechanism. We used SignalP v4.1, TargetP v1.1, TMHMM v2.0, and EffectorP v2.0 to screen the candidate effector proteins in P. triticina isolates – KHTT, JHKT, and THSN. As a result, a total of 635 candidate effector proteins were obtained. Structural analysis showed that effector proteins were small in size (50AA to 422AA) and of diverse sequences, and the conserved sequential elements or clear common elements were not involved, regardless of their secretion from the pathogen to the host. There were 427 candidate effector proteins that contain more than or equal to 4 cysteine residues, and 339 candidate effector proteins contained the known motifs. Sixteen families, 9 domains, and 53 other known functional types were found in 186 candidate effector proteins using the Pfam search. Three novel motifs were found by MEME. Heterogeneous expression system was performed to verify the functions of 30 candidate effectors by inhibiting the programmed cell death (PCD) induced by BAX (the mouse-apoptotic gene elicitor) on Nicotiana benthamiana. Hypersensitive response (HR) can be induced by the six effectors in the wheat leaf rust resistance near isogenic lines, and this would be shown by the method of transient expression through Agrobacterium tumefaciens infiltration. The quantitative reverse transcription PCR (qRT-PCR) analysis of 14 candidate effector proteins secreted after P. triticina inoculation showed that the tested effectors displayed different expression patterns in different stages, suggesting that they may be involved in the wheat–P. triticina interaction. The results showed that the prediction of P. triticina effector proteins based on transcriptomic analysis and multiple bioinformatics software is effective and more accurate, laying the foundation of revealing the pathogenic mechanism of Pt and controlling disease.
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Affiliation(s)
- Yue Zhang
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China
| | - Jie Wei
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China
| | - Yue Qi
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China
| | - Jianyuan Li
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China.,College of Biological Sciences and Engineering, Hebei Xingtai College, Xingtai, China
| | - Raheela Amin
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China
| | - Wenxiang Yang
- College of Plant Protection, Technological Innovation Center for Biological Control of Crop Diseases and Insect Pests of Hebei Province, Hebei Agricultural University, Baoding, China
| | - Daqun Liu
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
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17
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Montenegro Alonso AP, Ali S, Song X, Linning R, Bakkeren G. UhAVR1, an HR-Triggering Avirulence Effector of Ustilago hordei, Is Secreted via the ER-Golgi Pathway, Localizes to the Cytosol of Barley Cells during in Planta-Expression, and Contributes to Virulence Early in Infection. J Fungi (Basel) 2020; 6:E178. [PMID: 32961976 PMCID: PMC7559581 DOI: 10.3390/jof6030178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
The basidiomycete Ustilago hordei causes covered smut disease of barley and oats. Virulence effectors promoting infection and supporting pathogen lifestyle have been described for this fungus. Genetically, six avirulence genes are known and one codes for UhAVR1, the only proven avirulence effector identified in smuts to date that triggers complete immunity in barley cultivars carrying resistance gene Ruh1. A prerequisite for resistance breeding is understanding the host targets and molecular function of UhAVR1. Analysis of this effector upon natural infection of barley coleoptiles using teliospores showed that UhAVR1 is expressed during the early stages of fungal infection where it leads to HR triggering in resistant cultivars or performs its virulence function in susceptible cultivars. Fungal secretion of UhAVR1 is directed by its signal peptide and occurs via the BrefeldinA-sensitive ER-Golgi pathway in cell culture away from its host. Transient in planta expression of UhAVR1 in barley and a nonhost, Nicotiana benthamiana, supports a cytosolic localization. Delivery of UhAVR1 via foxtail mosaic virus or Pseudomonas species in both barley and N. benthamiana reveals a role in suppressing components common to both plant systems of Effector- and Pattern-Triggered Immunity, including necrosis triggered by Agrobacterium-delivered cell death inducers.
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Affiliation(s)
- Ana Priscilla Montenegro Alonso
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Shawkat Ali
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, Kentville, NS B4N 1J5, Canada;
| | - Xiao Song
- Sandstone Pharmacies Glenmore Landing Calgary-Compounding, 167D, 1600–90 Ave SW Calgary, AB T2V 5A8, Canada;
| | - Rob Linning
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Guus Bakkeren
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
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18
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Jaswal R, Rajarammohan S, Dubey H, Sharma TR. Smut fungi as a stratagem to characterize rust effectors: opportunities and challenges. World J Microbiol Biotechnol 2020; 36:150. [PMID: 32924088 DOI: 10.1007/s11274-020-02927-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 09/05/2020] [Indexed: 11/30/2022]
Abstract
The rust pathogens are one of the most complex fungi in the Basidiomycetes. The development of genomic resources for rust and other plant pathogens has opened the opportunities for functional genomics of fungal genes. Despite significant progress in the field of fungal genomics, functional characterization of the genome components has lacked, especially for the rust pathogens. Their obligate nature and lack of standard stable transformation protocol are the primary reasons for rusts to be one of the least explored genera despite its significance. In the recently sequenced rust genomes, a vast catalogue of predicted effectors and pathogenicity genes have been reported. However, most of these candidate genes remained unexplored due to the lack of suitable characterization methods. The heterologous expression of putative effectors in Nicotiana benthamiana and Arabidopsis thaliana has proved to be a rapid screening method for identifying the role of these effectors in virulence. However, no fungal system has been used for the functional validation of these candidate genes. The smuts, from the evolutionary point of view, are closely related to the rust pathogens. Moreover, they have been widely studied and hence could be a suitable model system for expressing rust fungal genes heterologously. The genetic manipulation methods for smuts are also well standardized. Complementation assays can be used for functional validation of the homologous genes present in rust and smut fungal pathogens, while the species-specific proteins can be expressed in the mutant strains of smut pathogens having reduced or no virulence for virulence analysis. We propose that smuts, especially Ustilago maydis, may prove to be a good model system to characterize rust effector proteins in the absence of methods to manipulate the rust genomes directly.
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Affiliation(s)
- Rajdeep Jaswal
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India
| | - Sivasubramanian Rajarammohan
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India
| | - Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology, Pusa Campus, New Delhi, 110012, India
| | - T R Sharma
- National Agri-Food Biotechnology Institute (NABI), Sector-81 (Knowledge City), PO Manauli, S.A.S. Nagar, Mohali, Punjab, 140306, India.
- Crop Science Division, Indian Council of Agricultural Research, New Delhi, 110001, India.
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19
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Sun W, Fan J, Fang A, Li Y, Tariqjaveed M, Li D, Hu D, Wang WM. Ustilaginoidea virens: Insights into an Emerging Rice Pathogen. ANNUAL REVIEW OF PHYTOPATHOLOGY 2020; 58:363-385. [PMID: 32364825 DOI: 10.1146/annurev-phyto-010820-012908] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
False smut of rice, caused by Ustilaginoidea virens, has become one of the most important diseases in rice-growing regions worldwide. The disease causes a significant yield loss and imposes health threats to humans and animals by producing mycotoxins. In this review, we update our understanding of the pathogen, including the disease cycle and infection strategies, the decoding of the U. virens genome, comparative/functional genomics, and effector biology. Whereas the decoding of the U. virens genome unveils specific adaptations of the pathogen in successfully occupying rice flowers, progresses in comparative/functional genomics and effector biology have begun to uncover the molecular mechanisms underlying U. virens virulence and pathogenicity. We highlight the identification and characterization of the produced mycotoxins and their biosynthetic pathways in U. virens.The management strategies for this disease are also discussed. The flower-specific infection strategy makes the pathogen a unique tool to unveil novel mechanisms for the interactions between nonobligate biotrophic pathogens and their hosts.
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Affiliation(s)
- Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
| | - Anfei Fang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuejiao Li
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Muhammad Tariqjaveed
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Dayong Li
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
| | - Dongwei Hu
- State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
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20
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Jaswal R, Kiran K, Rajarammohan S, Dubey H, Singh PK, Sharma Y, Deshmukh R, Sonah H, Gupta N, Sharma TR. Effector Biology of Biotrophic Plant Fungal Pathogens: Current Advances and Future Prospects. Microbiol Res 2020; 241:126567. [PMID: 33080488 DOI: 10.1016/j.micres.2020.126567] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/13/2022]
Abstract
The interaction of fungal pathogens with their host requires a novel invading mechanism and the presence of various virulence-associated components responsible for promoting the infection. The small secretory proteins, explicitly known as effector proteins, are one of the prime mechanisms of host manipulation utilized by the pathogen to disarm the host. Several effector proteins are known to translocate from fungus to the plant cell for host manipulation. Many fungal effectors have been identified using genomic, transcriptomic, and bioinformatics approaches. Most of the effector proteins are devoid of any conserved signatures, and their prediction based on sequence homology is very challenging, therefore by combining the sequence consensus based upon machine learning features, multiple tools have also been developed for predicting apoplastic and cytoplasmic effectors. Various post-genomics approaches like transcriptomics of virulent isolates have also been utilized for identifying active consortia of effectors. Significant progress has been made in understanding biotrophic effectors; however, most of it is underway due to their complex interaction with host and complicated recognition and signaling networks. This review discusses advances, and challenges in effector identification and highlighted various features of the potential effector proteins and approaches for understanding their genetics and strategies for regulation.
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Affiliation(s)
- Rajdeep Jaswal
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India; Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India
| | - Kanti Kiran
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | | | - Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | - Pankaj Kumar Singh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Yogesh Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Humira Sonah
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Naveen Gupta
- Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India.
| | - T R Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India.
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21
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Carreón-Anguiano KG, Islas-Flores I, Vega-Arreguín J, Sáenz-Carbonell L, Canto-Canché B. EffHunter: A Tool for Prediction of Effector Protein Candidates in Fungal Proteomic Databases. Biomolecules 2020; 10:biom10050712. [PMID: 32375409 PMCID: PMC7277995 DOI: 10.3390/biom10050712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/17/2020] [Accepted: 03/21/2020] [Indexed: 11/16/2022] Open
Abstract
Pathogens are able to deliver small-secreted, cysteine-rich proteins into plant cells to enable infection. The computational prediction of effector proteins remains one of the most challenging areas in the study of plant fungi interactions. At present, there are several bioinformatic programs that can help in the identification of these proteins; however, in most cases, these programs are managed independently. Here, we present EffHunter, an easy and fast bioinformatics tool for the identification of effectors. This predictor was used to identify putative effectors in 88 proteomes using characteristics such as size, cysteine residue content, secretion signal and transmembrane domains.
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Affiliation(s)
- Karla Gisel Carreón-Anguiano
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 X 32 y 34, Col. Chuburná de Hidalgo, C.P. 97205 Mérida, México
| | - Ignacio Islas-Flores
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 X 32 y 34, Col. Chuburná de Hidalgo, C.P. 97205 Mérida, México
| | - Julio Vega-Arreguín
- Laboratorio de Ciencias AgroGenómicas, Escuela Nacional de Estudios Superiores-UNAM, León, México
| | - Luis Sáenz-Carbonell
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 X 32 y 34, Col. Chuburná de Hidalgo, C.P. 97205 Mérida, México
| | - Blondy Canto-Canché
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 X 32 y 34, Col. Chuburná de Hidalgo, C.P. 97205 Mérida, México
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22
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Gene silencing of Diaphorina citri candidate effectors promotes changes in feeding behaviors. Sci Rep 2020; 10:5992. [PMID: 32265528 PMCID: PMC7138822 DOI: 10.1038/s41598-020-62856-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 03/12/2020] [Indexed: 12/22/2022] Open
Abstract
Insect effectors are mainly secreted by salivary glands, modulate plant physiology and favor the establishment and transmission of pathogens. Feeding is the principal vehicle of transmission of Candidatus Liberibacter asiaticus (Ca. Las) by the Asian citrus psyllid (ACP), Diaphorina citri. This study aimed to predict putative ACP effectors that may act on the Huanglongbing (HLB) pathosystem. Bioinformatics analysis led to the identification of 131 candidate effectors. Gene expression investigations were performed to select genes that were overexpressed in the ACP head and modulated by Ca. Las. To evaluate the actions of candidate effectors on D. citri feeding, six effectors were selected for gene silencing bioassays. Double-stranded RNAs (dsRNAs) of the target genes were delivered to D. citri adults via artificial diets for five days. RNAi silencing caused a reduction in the ACP lifespan and decreased the salivary sheath size and honeydew production. Moreover, after dsRNA delivery of the target genes using artificial diet, the feeding behaviors of the insects were evaluated on young leaves from citrus seedlings. These analyses proved that knockdown of D. citri effectors also interfered with ACP feeding abilities in planta, causing a decrease in honeydew production and reducing ACP survival. Electrical penetration graph (EPG) analysis confirmed the actions of the effectors on D. citri feeding behaviors. These results indicate that gene silencing of D. citri effectors may cause changes in D. citri feeding behaviors and could potentially be used for ACP control.
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23
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Seifbarghi S, Borhan MH, Wei Y, Ma L, Coutu C, Bekkaoui D, Hegedus DD. Receptor-Like Kinases BAK1 and SOBIR1 Are Required for Necrotizing Activity of a Novel Group of Sclerotinia sclerotiorum Necrosis-Inducing Effectors. FRONTIERS IN PLANT SCIENCE 2020; 11:1021. [PMID: 32754179 PMCID: PMC7367142 DOI: 10.3389/fpls.2020.01021] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 06/22/2020] [Indexed: 05/03/2023]
Abstract
Sclerotinia sclerotiorum is a characteristic necrotrophic plant pathogen and is dependent on the induction of host cell death for nutrient acquisition. To identify necrosis-inducing effectors, the genome of S. sclerotiorum was scanned for genes encoding small, secreted, cysteine-rich proteins. These potential effectors were tested for their ability to induce necrosis in Nicotiana benthamiana via Agrobacterium-mediated expression and for cellular localization in host cells. Six novel proteins were discovered, of which all but one required a signal peptide for export to the apoplast for necrotizing activity. Virus-induced gene silencing revealed that the five necrosis-inducing effectors with a requirement for secretion also required the plant co-receptor-like kinases Brassinosteroid Insensitive 1-Associated Receptor Kinase 1 (BAK1) and Suppressor of BAK1-Interacting Receptor-like Kinase 1 (SOBIR1) for the induction of necrosis. S. sclerotiorum necrosis-inducing effector 2 (SsNE2) represented a new class of necrosis-inducing proteins as orthologs were identified in several other phytopathogenic fungi that were also capable of inducing necrosis. Substitution of conserved cysteine residues with alanine reduced, but did not abolish, the necrotizing activity of SsNE2 and full-length protein was required for function as peptides spanning the entire protein were unable to induce necrosis. These results illustrate the importance of necrosis-inducing effectors for S. sclerotiorum virulence and the role of host extracellular receptor(s) in effector-triggered susceptibility to this pathogen.
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Affiliation(s)
- Shirin Seifbarghi
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lisong Ma
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
| | - Cathy Coutu
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
| | | | - Dwayne D. Hegedus
- Agriculture and Agri-Food Canada, Saskatoon, SK, Canada
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Dwayne D. Hegedus,
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Tabima JF, Grünwald NJ. effectR: An Expandable R Package to Predict Candidate RxLR and CRN Effectors in Oomycetes Using Motif Searches. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1067-1076. [PMID: 30951442 DOI: 10.1094/mpmi-10-18-0279-ta] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Effectors are small, secreted proteins that facilitate infection of host plants by all major groups of plant pathogens. Effector protein identification in oomycetes relies on identification of open reading frames with certain amino acid motifs among additional minor criteria. To date, identification of effectors relies on custom scripts to identify motifs in candidate open reading frames. Here, we developed the R package effectR, which provides a convenient tool for rapid prediction of effectors in oomycete genomes, or with custom scripts for any genome, in a reproducible way. The effectR package relies on a combination of regular expressions statements and hidden Markov model approaches to predict candidate RxLR and crinkler effectors. Other custom motifs for novel effectors can easily be implemented and added to package updates. The effectR package has been validated with published oomycete genomes. This package provides a convenient tool for wet lab researchers interested in reproducible identification of candidate effectors in oomycete genomes.
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Affiliation(s)
- Javier F Tabima
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Niklaus J Grünwald
- Horticultural Crops Research Laboratory, USDA-ARS, Corvallis, OR 97330, U.S.A
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Neu E, Debener T. Prediction of the Diplocarpon rosae secretome reveals candidate genes for effectors and virulence factors. Fungal Biol 2018; 123:231-239. [PMID: 30798878 DOI: 10.1016/j.funbio.2018.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 12/16/2018] [Accepted: 12/17/2018] [Indexed: 01/01/2023]
Abstract
Rose black spot is one of the most severe diseases of field-grown roses. Though R-genes have been characterised, little information is known about the molecular details of the interaction between pathogen and host. Based on the recently published genome sequence of the black spot fungus, we analysed gene models with various bioinformatic tools utilising the expression data of infected host tissues, which led to the prediction of 827 secreted proteins. A significant proportion of the predicted secretome comprises enzymes for the degradation of cell wall components, several of which were highly expressed during the first infection stages. As the secretome comprises major factors determining the ability of the fungus to colonise its host, we focused our further analyses on predicted effector candidates. In total, 52 sequences of 251 effector candidates matched several bioinformatic criteria of effectors, contained a Y/F/WxC motif, and did not match annotated proteins from other fungi. Additional sequences were identified based on their high expression levels during the penetration/haustorium formation phase and/or by matching known effectors from other fungi. Several host genotypes that are resistant to the sequenced isolate but differ in the R-genes responsible for this resistance are available. The combination of these genotypes with functional studies of the identified candidate effectors will allow the mechanisms of the rose black spot interaction to be dissected.
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Affiliation(s)
- Enzo Neu
- Department of Molecular Plant Breeding, Institute for Plant Genetics, Leibniz Universität Hannover, Herrenhaeuser Str. 2, Hannover 30419, Germany
| | - Thomas Debener
- Department of Molecular Plant Breeding, Institute for Plant Genetics, Leibniz Universität Hannover, Herrenhaeuser Str. 2, Hannover 30419, Germany.
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Chang HX, Noel ZA, Sang H, Chilvers MI. Annotation resource of tandem repeat-containing secretory proteins in sixty fungi. Fungal Genet Biol 2018; 119:7-19. [PMID: 30026018 DOI: 10.1016/j.fgb.2018.07.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/06/2018] [Accepted: 07/15/2018] [Indexed: 11/17/2022]
Abstract
Fungal secretory proteins that interact with host plants are regarded as effectors. Because fungal effectors rarely contain conserved sequence features, identification and annotation of fungal effectors from predicted secretory proteins are difficult using outward comparison methods such as BLAST or hidden Markov model. In desire of more sequence features to prioritize research interests of fungal secretory proteins, this study developed a pipeline to identify tandem repeat (TR) domain within putative secretory proteins and tested a hypothesis that at least one type of TR domain in non-orthologous secretory proteins has emerged from convergent evolution for plant pathogenicity. There were 2804 types of TR domains and a total of 2925 TR-containing secretory proteins found from 60 fungi. There was no conserved type of TR domain shared only by plant pathogens, indicating functional divergence for different types of TR domain and TR-containing secretory proteins. The annotation resource of putative fungal TR-containing secretory proteins provides new sequence features that will be useful for the community interested in fungal effector biology.
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Affiliation(s)
- Hao-Xun Chang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824, MI, United States
| | - Zachary A Noel
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824, MI, United States
| | - Hyunkyu Sang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824, MI, United States
| | - Martin I Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing 48824, MI, United States.
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Deb D, Mackey D, Opiyo SO, McDowell JM. Application of alignment-free bioinformatics methods to identify an oomycete protein with structural and functional similarity to the bacterial AvrE effector protein. PLoS One 2018; 13:e0195559. [PMID: 29641586 PMCID: PMC5895030 DOI: 10.1371/journal.pone.0195559] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 03/23/2018] [Indexed: 11/23/2022] Open
Abstract
Diverse plant pathogens export effector proteins to reprogram host cells. One of the most challenging goals in the molecular plant-microbe field is to functionally characterize the complex repertoires of effectors secreted by these pathogens. For bacterial pathogens, the predominant class of effectors is delivered to host cells by Type III secretion. For oomycetes, the predominant class of effectors is defined by a signal peptide that mediates secretion from the oomycete and a conserved RxLR motif. Downy mildew pathogens and Phytophthora species maintain hundreds of candidate RxLR effector genes in their genomes. Although no primary sequence similarity is evident between bacterial Type III effectors (T3Es) and oomycete RXLR effectors, some bacterial and oomycete effectors have convergently evolved to target the same host proteins. Such effectors might have evolved domains that are functionally similar but sequence-unrelated. We reasoned that alignment-free bioinformatics approaches could be useful to identify structural similarities between bacterial and oomycete effectors. To test this approach, we used partial least squares regression, alignment-free bioinformatics methods to identify effector proteins from the genome of the oomycete Hyaloperonospora arabidopsidis that are similar to the well-studied AvrE1 effector from Pseudomonas syringae. This approach identified five RxLR proteins with putative structural similarity to AvrE1. We focused on one, HaRxL23, because it is an experimentally validated effector and it is conserved between distantly related oomycetes. Several experiments indicate that HaRxL23 is functionally similar to AvrE1, including the ability to partially rescue an AvrE1 loss-of-function mutant. This study provides an example of how an alignment-free bioinformatics approach can identify functionally similar effector proteins in the absence of primary sequence similarity. This approach could be useful to identify effectors that have convergently evolved regardless of whether the shared host target is known.
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Affiliation(s)
- Devdutta Deb
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
| | - David Mackey
- Departments of Horticulture and Crop Science and Molecular Genetics, Ohio State University, Columbus, Ohio, United States of America
| | - Stephen O. Opiyo
- Molecular and Cellular Imaging Center-Columbus, Ohio Agricultural Research and Development Center, Ohio State University, Columbus, Ohio, United States of America
- * E-mail: (SOO); (JMM)
| | - John M. McDowell
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail: (SOO); (JMM)
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