1
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Li T, Moreno-Pérez A, Coaker G. Plant Pattern recognition receptors: Exploring their evolution, diversification, and spatiotemporal regulation. CURRENT OPINION IN PLANT BIOLOGY 2024; 82:102631. [PMID: 39303367 DOI: 10.1016/j.pbi.2024.102631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 08/02/2024] [Accepted: 08/29/2024] [Indexed: 09/22/2024]
Abstract
Plant genomes possess hundreds of candidate surface localized receptors capable of recognizing microbial components or modified-self molecules. Surface-localized pattern recognition receptors (PRRs) can recognize proteins, peptides, or structural microbial components as nonself, triggering complex signaling pathways leading to defense. PRRs possess diverse extracellular domains capable of recognizing epitopes, lipids, glycans and polysaccharides. Recent work highlights advances in our understanding of the diversity and evolution of PRRs recognizing pathogen components. We also discuss PRR functional diversification, pathogen strategies to evade detection, and the role of tissue and age-related resistance for effective plant defense.
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Affiliation(s)
- Tianrun Li
- Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Alba Moreno-Pérez
- Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Gitta Coaker
- Department of Plant Pathology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
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2
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Pejenaute-Ochoa MD, Tomás-Gallardo L, Ibeas JI, Barrales RR. Row1, a member of a new family of conserved fungal proteins involved in infection, is required for appressoria functionality in Ustilago maydis. THE NEW PHYTOLOGIST 2024; 243:1101-1122. [PMID: 38742361 DOI: 10.1111/nph.19798] [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: 09/12/2023] [Accepted: 04/17/2024] [Indexed: 05/16/2024]
Abstract
The appressorium of phytopathogenic fungi is a specific structure with a crucial role in plant cuticle penetration. Pathogens with melanized appressoria break the cuticle through cell wall melanization and intracellular turgor pressure. However, in fungi with nonmelanized appressorium, the mechanisms governing cuticle penetration are poorly understood. Here we characterize Row1, a previously uncharacterized appressoria-specific protein of Ustilago maydis that localizes to membrane and secretory vesicles. Deletion of row1 decreases appressoria formation and plant penetration, thereby reducing virulence. Specifically, the Δrow1 mutant has a thicker cell wall that is more resistant to glucanase degradation. We also observed that the Δrow1 mutant has secretion defects. We show that Row1 is functionally conserved at least among Ustilaginaceae and belongs to the Row family, which consists of five other proteins that are highly conserved among Basidiomycota fungi and are involved in U. maydis virulence. We observed similarities in localization between Row1 and Row2, which is also involved in cell wall remodelling and secretion, suggesting similar molecular functions for members of this protein family. Our data suggest that Row1 could modify the chitin-glucan matrix of the fungal cell wall and may be involved in unconventional protein secretion, thereby promoting both appressoria maturation and penetration.
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Affiliation(s)
- María Dolores Pejenaute-Ochoa
- Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-CSIC-Junta de Andalucía, Ctra. Utrera km.1, 41013, Seville, Spain
| | - Laura Tomás-Gallardo
- Proteomics and Biochemistry Platform, Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-CSIC-Junta de Andalucía, Ctra. Utrera km. 1, 41013, Seville, Spain
| | - José I Ibeas
- Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-CSIC-Junta de Andalucía, Ctra. Utrera km.1, 41013, Seville, Spain
| | - Ramón R Barrales
- Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide-CSIC-Junta de Andalucía, Ctra. Utrera km.1, 41013, Seville, Spain
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3
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Shree A, Pal S, Verma PK. Structural diversification of fungal cell wall in response to the stress signaling and remodeling during fungal pathogenesis. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2024; 30:733-747. [PMID: 38846457 PMCID: PMC11150350 DOI: 10.1007/s12298-024-01453-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 06/09/2024]
Abstract
Fungi are one of the most diverse organisms found in our surroundings. The heterotrophic lifestyle of fungi and the ever-changing external environmental factors pose numerous challenges for their survival. Despite all adversities, fungi continuously develop new survival strategies to secure nutrition and space from their host. During host-pathogen interaction, filamentous phytopathogens in particular, effectively infect their hosts by maintaining polarised growth at the tips of hyphae. The fungal cell wall, being the prime component of host contact, plays a crucial role in fortifying the intracellular environment against the harsh external environment. Structurally, the fungal cell wall is a highly dynamic yet rigid component, responsible for maintaining cellular morphology. Filamentous pathogens actively maintain their dynamic cell wall to compensate rapid growth on the host. Additionally, they secrete effectors to dampen the sophisticated mechanisms of plant defense and initiate various downstream signaling cascades to repair the damage inflicted by the host. Thus, the fungal cell wall serves as a key modulator of fungal pathogenicity. The fungal cell wall with their associated signaling mechanisms emerge as intriguing targets for host immunity. This review comprehensively examines and summarizes the multifaceted findings of various research groups regarding the dynamics of the cell wall in filamentous fungal pathogens during host invasion.
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Affiliation(s)
- Ankita Shree
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Surabhi Pal
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Praveen Kumar Verma
- Plant Immunity Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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4
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Sivaramakrishnan M, Veeraganti Naveen Prakash C, Chandrasekar B. Multifaceted roles of plant glycosyl hydrolases during pathogen infections: more to discover. PLANTA 2024; 259:113. [PMID: 38581452 DOI: 10.1007/s00425-024-04391-5] [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: 08/04/2023] [Accepted: 03/15/2024] [Indexed: 04/08/2024]
Abstract
MAIN CONCLUSION Carbohydrates are hydrolyzed by a family of carbohydrate-active enzymes (CAZymes) called glycosidases or glycosyl hydrolases. Here, we have summarized the roles of various plant defense glycosidases that possess different substrate specificities. We have also highlighted the open questions in this research field. Glycosidases or glycosyl hydrolases (GHs) are a family of carbohydrate-active enzymes (CAZymes) that hydrolyze glycosidic bonds in carbohydrates and glycoconjugates. Compared to those of all other sequenced organisms, plant genomes contain a remarkable diversity of glycosidases. Plant glycosidases exhibit activities on various substrates and have been shown to play important roles during pathogen infections. Plant glycosidases from different GH families have been shown to act upon pathogen components, host cell walls, host apoplastic sugars, host secondary metabolites, and host N-glycans to mediate immunity against invading pathogens. We could classify the activities of these plant defense GHs under eleven different mechanisms through which they operate during pathogen infections. Here, we have provided comprehensive information on the catalytic activities, GH family classification, subcellular localization, domain structure, functional roles, and microbial strategies to regulate the activities of defense-related plant GHs. We have also emphasized the research gaps and potential investigations needed to advance this topic of research.
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Affiliation(s)
| | | | - Balakumaran Chandrasekar
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani (BITS Pilani), Pilani, 333031, India.
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5
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John E, Chau MQ, Hoang CV, Chandrasekharan N, Bhaskar C, Ma LS. Fungal Cell Wall-Associated Effectors: Sensing, Integration, Suppression, and Protection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2024; 37:196-210. [PMID: 37955547 DOI: 10.1094/mpmi-09-23-0142-fi] [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: 11/14/2023]
Abstract
The cell wall (CW) of plant-interacting fungi, as the direct interface with host plants, plays a crucial role in fungal development. A number of secreted proteins are directly associated with the fungal CW, either through covalent or non-covalent interactions, and serve a range of important functions. In the context of plant-fungal interactions many are important for fungal development in the host environment and may therefore be considered fungal CW-associated effectors (CWAEs). Key CWAE functions include integrating chemical/physical signals to direct hyphal growth, interfering with plant immunity, and providing protection against plant defenses. In recent years, a diverse range of mechanisms have been reported that underpin their roles, with some CWAEs harboring conserved motifs or functional domains, while others are reported to have novel features. As such, the current understanding regarding fungal CWAEs is systematically presented here from the perspective of their biological functions in plant-fungal interactions. An overview of the fungal CW architecture and the mechanisms by which proteins are secreted, modified, and incorporated into the CW is first presented to provide context for their biological roles. Some CWAE functions are reported across a broad range of pathosystems or symbiotic/mutualistic associations. Prominent are the chitin interacting-effectors that facilitate fungal CW modification, protection, or suppression of host immune responses. However, several alternative functions are now reported and are presented and discussed. CWAEs can play diverse roles, some possibly unique to fungal lineages and others conserved across a broad range of plant-interacting fungi. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Evan John
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Minh-Quang Chau
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Cuong V Hoang
- Centro de Biotecnología y Genómica de Plantas, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Universidad Politécnica de Madrid (UPM), Campus de Montegancedo UPM, 28223 Pozuelo de Alarcón, Spain
| | | | - Chibbhi Bhaskar
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Lay-Sun Ma
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
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6
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Hu S, Jin M, Xu Y, Wu Q, Jiang Q, Ma J, Zhang Y, Qi P, Chen G, Jiang Y, Zheng Y, Wei Y, Xu Q. Deacetylation of chitin oligomers by Fusarium graminearum polysaccharide deacetylase suppresses plant immunity. MOLECULAR PLANT PATHOLOGY 2023; 24:1495-1509. [PMID: 37746915 PMCID: PMC10632789 DOI: 10.1111/mpp.13387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/29/2023] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
Chitin is a long-chain polymer of β-1,4-linked N-acetylglucosamine that forms rigid microfibrils to maintain the hyphal form and protect it from host attacks. Chitin oligomers are first recognized by the plant receptors in the apoplast region, priming the plant's immune system. Here, seven polysaccharide deacetylases (PDAs) were identified and their activities on chitin substrates were investigated via systematic characterization of the PDA family from Fusarium graminearum. Among these PDAs, FgPDA5 was identified as an important virulence factor and was specifically expressed during pathogenesis. ΔFgpda5 compromised the pathogen's ability to infect wheat. The polysaccharide deacetylase structure of FgPDA5 is essential for the pathogenicity of F. graminearum. FgPDA5 formed a homodimer and accumulated in the plant apoplast. In addition, FgPDA5 showed a high affinity toward chitin substrates. FgPDA5-mediated deacetylation of chitin oligomers prevented activation of plant defence responses. Overall, our results identify FgPDA5 as a polysaccharide deacetylase that can prevent chitin-triggered host immunity in plant apoplast through deacetylation of chitin oligomers.
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Affiliation(s)
- Su Hu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Minxia Jin
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Yangjie Xu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Qin Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Qiantao Jiang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Jian Ma
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Yazhou Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Pengfei Qi
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Guoyue Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Yunfeng Jiang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Youliang Zheng
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Yuming Wei
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
| | - Qiang Xu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest ChinaSichuan Agricultural UniversityChengduChina
- Triticeae Research InstituteSichuan Agricultural UniversityChengduChina
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7
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Xiao M, Chen D, Liu S, Chen A, Fang A, Tian B, Yu Y, Bi C, Kang Z, Yang Y. A chitin deacetylase PsCDA2 from Puccinia striiformis f. sp. tritici confers disease pathogenicity by suppressing chitin-triggered immunity in wheat. MOLECULAR PLANT PATHOLOGY 2023; 24:1467-1479. [PMID: 37486146 PMCID: PMC10632782 DOI: 10.1111/mpp.13381] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/25/2023]
Abstract
Plants have the ability to recognize the essential chitin molecule present in the fungal cell wall, which stimulates the immune response. Phytopathogenic fungi have developed various strategies to inhibit the chitin-triggered immune response. Here, we identified a chitin deacetylase of Puccinia striiformis f. sp. tritici (Pst), known as PsCDA2, that was induced during the initial invasion of wheat and acted as an inhibitor of plant cell death. Knockdown of PsCDA2 in wheat enhanced its resistance against Pst, highlighting the significance of PsCDA2 in the host-pathogen interaction. Moreover, PsCDA2 can protect Pst urediniospores from being damaged by host chitinase in vitro. PsCDA2 also suppressed the basal chitin-induced plant immune response, including the accumulation of callose and the expression of defence genes. Overall, our results demonstrate that Pst secretes PsCDA2 as a chitin deacetylase involved in establishing infection and modifying the acetyl group to prevent the breakdown of chitin in the cell wall by host endogenous chitinases. Our research unveils a mechanism by which the fungus suppresses plant immunity, further contributing to the understanding of wheat stripe rust control. This information could have significant implications for the development of suitable strategies for protecting crops against the devastating effects of this disease.
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Affiliation(s)
- Muye Xiao
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Dezhi Chen
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Saifei Liu
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Anle Chen
- Chongqing Academy of Agriculture SciencesChongqingChina
| | - Anfei Fang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Binnian Tian
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Yang Yu
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Chaowei Bi
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Yuheng Yang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant ProtectionSouthwest UniversityChongqingChina
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8
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Liu H, Lu X, Li M, Lun Z, Yan X, Yin C, Yuan G, Wang X, Liu N, Liu D, Wu M, Luo Z, Zhang Y, Bhadauria V, Yang J, Talbot NJ, Peng YL. Plant immunity suppression by an exo-β-1,3-glucanase and an elongation factor 1α of the rice blast fungus. Nat Commun 2023; 14:5491. [PMID: 37679340 PMCID: PMC10484928 DOI: 10.1038/s41467-023-41175-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/23/2023] [Indexed: 09/09/2023] Open
Abstract
Fungal cell walls undergo continual remodeling that generates β-1,3-glucan fragments as products of endo-glycosyl hydrolases (GHs), which can be recognized as pathogen-associated molecular patterns (PAMPs) and trigger plant immune responses. How fungal pathogens suppress those responses is often poorly understood. Here, we study mechanisms underlying the suppression of β-1,3-glucan-triggered plant immunity by the blast fungus Magnaporthe oryzae. We show that an exo-β-1,3-glucanase of the GH17 family, named Ebg1, is important for fungal cell wall integrity and virulence of M. oryzae. Ebg1 can hydrolyze β-1,3-glucan and laminarin into glucose, thus suppressing β-1,3-glucan-triggered plant immunity. However, in addition, Ebg1 seems to act as a PAMP, independent of its hydrolase activity. This Ebg1-induced immunity appears to be dampened by the secretion of an elongation factor 1 alpha protein (EF1α), which interacts and co-localizes with Ebg1 in the apoplast. Future work is needed to understand the mechanisms behind Ebg1-induced immunity and its suppression by EF1α.
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Affiliation(s)
- Hang Liu
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Xunli Lu
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Mengfei Li
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Zhiqin Lun
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Xia Yan
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Changfa Yin
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Guixin Yuan
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Xingbin Wang
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Ning Liu
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Di Liu
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Mian Wu
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Ziluolong Luo
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Yan Zhang
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Vijai Bhadauria
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Jun Yang
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich Research Park, Norwich, NR4 7UH, UK
| | - You-Liang Peng
- Ministry of Agriculture and Rural Affairs Key Laboratory for Crop Pest Monitoring and Green Control, China Agricultural University, Beijing, 100193, China.
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9
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Wu XM, Zhang BS, Zhao YL, Wu HW, Gao F, Zhang J, Zhao JH, Guo HS. DeSUMOylation of a Verticillium dahliae enolase facilitates virulence by derepressing the expression of the effector VdSCP8. Nat Commun 2023; 14:4844. [PMID: 37563142 PMCID: PMC10415295 DOI: 10.1038/s41467-023-40384-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 07/24/2023] [Indexed: 08/12/2023] Open
Abstract
The soil-borne fungus Verticillium dahliae, the most notorious plant pathogen of the Verticillium genus, causes vascular wilts in a wide variety of economically important crops. The molecular mechanism of V. dahliae pathogenesis remains largely elusive. Here, we identify a small ubiquitin-like modifier (SUMO)-specific protease (VdUlpB) from V. dahliae, and find that VdUlpB facilitates V. dahliae virulence by deconjugating SUMO from V. dahliae enolase (VdEno). We identify five lysine residues (K96, K254, K259, K313 and K434) that mediate VdEno SUMOylation, and SUMOylated VdEno preferentially localized in nucleus where it functions as a transcription repressor to inhibit the expression of an effector VdSCP8. Importantly, VdUlpB mediates deSUMOylation of VdEno facilitates its cytoplasmic distribution, which allows it to function as a glycolytic enzyme. Our study reveals a sophisticated pathogenic mechanism of VdUlpB-mediated enolase deSUMOylation, which fortifies glycolytic pathway for growth and contributes to V. dahliae virulence through derepressing the expression of an effector.
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Affiliation(s)
- Xue-Ming Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Bo-Sen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Yun-Long Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Hua-Wei Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Feng Gao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian-Hua Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China.
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing, 100049, China.
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10
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Talbi N, Fokkens L, Audran C, Petit‐Houdenot Y, Pouzet C, Blaise F, Gay EJ, Rouxel T, Balesdent M, Rep M, Fudal I. The neighbouring genes AvrLm10A and AvrLm10B are part of a large multigene family of cooperating effector genes conserved in Dothideomycetes and Sordariomycetes. MOLECULAR PLANT PATHOLOGY 2023; 24:914-931. [PMID: 37128172 PMCID: PMC10346447 DOI: 10.1111/mpp.13338] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 03/22/2023] [Accepted: 03/26/2023] [Indexed: 05/03/2023]
Abstract
Fungal effectors (small-secreted proteins) have long been considered as species or even subpopulation-specific. The increasing availability of high-quality fungal genomes and annotations has allowed the identification of trans-species or trans-genera families of effectors. Two avirulence effectors, AvrLm10A and AvrLm10B, of Leptosphaeria maculans, the fungus causing stem canker of oilseed rape, are members of such a large family of effectors. AvrLm10A and AvrLm10B are neighbouring genes, organized in divergent transcriptional orientation. Sequence searches within the L. maculans genome showed that AvrLm10A/AvrLm10B belong to a multigene family comprising five pairs of genes with a similar tail-to-tail organization. The two genes, in a pair, always had the same expression pattern and two expression profiles were distinguished, associated with the biotrophic colonization of cotyledons and/or petioles and stems. Of the two protein pairs further investigated, AvrLm10A_like1/AvrLm10B_like1 and AvrLm10A_like2/AvrLm10B_like2, the second one had the ability to physically interact, similarly to what was previously described for the AvrLm10A/AvrLm10B pair, and cross-interactions were also detected for two pairs. AvrLm10A homologues were identified in more than 30 Dothideomycete and Sordariomycete plant-pathogenic fungi. One of them, SIX5, is an effector from Fusarium oxysporum f. sp. lycopersici physically interacting with the avirulence effector Avr2. We found that AvrLm10A/SIX5 homologues were associated with at least eight distinct putative effector families, suggesting that AvrLm10A/SIX5 is able to cooperate with different effectors. These results point to a general role of the AvrLm10A/SIX5 proteins as "cooperating proteins", able to interact with diverse families of effectors whose encoding gene is co-regulated with the neighbouring AvrLm10A homologue.
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Affiliation(s)
- Nacera Talbi
- BIOGER, INRAEUniversité Paris‐SaclayPalaiseauFrance
| | - Like Fokkens
- Molecular Plant PathologyUniversity of AmsterdamAmsterdamNetherlands
- Present address:
Laboratory of PhytopathologyWageningen University and ResearchWageningenNetherlands
| | - Corinne Audran
- UMR LIPMEUniversité de Toulouse, INRAE, CNRSCastanet‐TolosanFrance
| | | | - Cécile Pouzet
- FRAIB‐TRI Imaging Platform Facilities, FR AIBUniversité de Toulouse, CNRSCastanet‐TolosanFrance
| | | | - Elise J. Gay
- BIOGER, INRAEUniversité Paris‐SaclayPalaiseauFrance
| | | | | | - Martijn Rep
- Molecular Plant PathologyUniversity of AmsterdamAmsterdamNetherlands
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11
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Bakhat N, Vielba-Fernández A, Padilla-Roji I, Martínez-Cruz J, Polonio Á, Fernández-Ortuño D, Pérez-García A. Suppression of Chitin-Triggered Immunity by Plant Fungal Pathogens: A Case Study of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii. J Fungi (Basel) 2023; 9:771. [PMID: 37504759 PMCID: PMC10381495 DOI: 10.3390/jof9070771] [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: 06/15/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
Fungal pathogens are significant plant-destroying microorganisms that present an increasing threat to the world's crop production. Chitin is a crucial component of fungal cell walls and a conserved MAMP (microbe-associated molecular pattern) that can be recognized by specific plant receptors, activating chitin-triggered immunity. The molecular mechanisms underlying the perception of chitin by specific receptors are well known in plants such as rice and Arabidopsis thaliana and are believed to function similarly in many other plants. To become a plant pathogen, fungi have to suppress the activation of chitin-triggered immunity. Therefore, fungal pathogens have evolved various strategies, such as prevention of chitin digestion or interference with plant chitin receptors or chitin signaling, which involve the secretion of fungal proteins in most cases. Since chitin immunity is a very effective defensive response, these fungal mechanisms are believed to work in close coordination. In this review, we first provide an overview of the current understanding of chitin-triggered immune signaling and the fungal proteins developed for its suppression. Second, as an example, we discuss the mechanisms operating in fungal biotrophs such as powdery mildew fungi, particularly in the model species Podosphaera xanthii, the main causal agent of powdery mildew in cucurbits. The key role of fungal effector proteins involved in the modification, degradation, or sequestration of immunogenic chitin oligomers is discussed in the context of fungal pathogenesis and the promotion of powdery mildew disease. Finally, the use of this fundamental knowledge for the development of intervention strategies against powdery mildew fungi is also discussed.
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Affiliation(s)
- Nisrine Bakhat
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Alejandra Vielba-Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Isabel Padilla-Roji
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Jesús Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Álvaro Polonio
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
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12
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Weiland P, Dempwolff F, Steinchen W, Freibert S, Tian H, Glatter T, Martin R, Thomma BPHJ, Bange G, Altegoer F. Structural and functional analysis of the cerato-platanin-like protein Cpl1 suggests diverging functions in smut fungi. MOLECULAR PLANT PATHOLOGY 2023; 24:768-787. [PMID: 37171083 PMCID: PMC10257043 DOI: 10.1111/mpp.13349] [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: 07/25/2022] [Revised: 03/28/2023] [Accepted: 04/19/2023] [Indexed: 05/13/2023]
Abstract
Plant-pathogenic fungi are causative agents of the majority of plant diseases and can lead to severe crop loss in infected populations. Fungal colonization is achieved by combining different strategies, such as avoiding and counteracting the plant immune system and manipulating the host metabolome. Of major importance are virulence factors secreted by fungi, which fulfil diverse functions to support the infection process. Most of these proteins are highly specialized, with structural and biochemical information often absent. Here, we present the atomic structures of the cerato-platanin-like protein Cpl1 from Ustilago maydis and its homologue Uvi2 from Ustilago hordei. Both proteins adopt a double-Ψβ-barrel architecture reminiscent of cerato-platanin proteins, a class so far not described in smut fungi. Our structure-function analysis shows that Cpl1 binds to soluble chitin fragments via two extended grooves at the dimer interface of the two monomer molecules. This carbohydrate-binding mode has not been observed previously and expands the repertoire of chitin-binding proteins. Cpl1 localizes to the cell wall of U. maydis and might synergize with cell wall-degrading and decorating proteins during maize infection. The architecture of Cpl1 harbouring four surface-exposed loop regions supports the idea that it might play a role in the spatial coordination of these proteins. While deletion of cpl1 has only mild effects on the virulence of U. maydis, a recent study showed that deletion of uvi2 strongly impairs U. hordei virulence. Our structural comparison between Cpl1 and Uvi2 reveals sequence variations in the loop regions that might explain a diverging function.
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Affiliation(s)
- Paul Weiland
- Center for Synthetic Microbiology (SYNMIKRO), Faculty of ChemistryPhilipps‐University MarburgMarburgGermany
| | - Felix Dempwolff
- Center for Synthetic Microbiology (SYNMIKRO), Faculty of ChemistryPhilipps‐University MarburgMarburgGermany
| | - Wieland Steinchen
- Center for Synthetic Microbiology (SYNMIKRO), Faculty of ChemistryPhilipps‐University MarburgMarburgGermany
| | - Sven‐Andreas Freibert
- Center for Synthetic Microbiology (SYNMIKRO), Institute of CytobiologyPhilipps‐University MarburgMarburgGermany
- Protein Biochemistry and Spectroscopy Core Facility, Institute of CytobiologyPhilipps‐University MarburgMarburgGermany
| | - Hui Tian
- Institute for Plant SciencesUniversity of CologneCologneGermany
| | - Timo Glatter
- Max‐Planck Institute for Terrestrial MicrobiologyMarburgGermany
| | - Roman Martin
- Faculty of Mathematics and Computer SciencePhilipps‐University MarburgMarburgGermany
| | - Bart P. H. J. Thomma
- Institute for Plant SciencesUniversity of CologneCologneGermany
- Cluster of Excellence on Plant Sciences (CEPLAS)CologneGermany
| | - Gert Bange
- Center for Synthetic Microbiology (SYNMIKRO), Faculty of ChemistryPhilipps‐University MarburgMarburgGermany
- Max‐Planck Institute for Terrestrial MicrobiologyMarburgGermany
| | - Florian Altegoer
- Center for Synthetic Microbiology (SYNMIKRO), Faculty of ChemistryPhilipps‐University MarburgMarburgGermany
- Max‐Planck Institute for Terrestrial MicrobiologyMarburgGermany
- Institute of MicrobiologyHeinrich‐Heine‐UniversityDüsseldorfGermany
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13
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Rocafort M, Srivastava V, Bowen JK, Díaz-Moreno SM, Guo Y, Bulone V, Plummer KM, Sutherland PW, Anderson MA, Bradshaw RE, Mesarich CH. Cell Wall Carbohydrate Dynamics during the Differentiation of Infection Structures by the Apple Scab Fungus, Venturia inaequalis. Microbiol Spectr 2023; 11:e0421922. [PMID: 37039647 PMCID: PMC10269774 DOI: 10.1128/spectrum.04219-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 03/15/2023] [Indexed: 04/12/2023] Open
Abstract
Scab, caused by the biotrophic fungal pathogen Venturia inaequalis, is the most economically important disease of apples. During infection, V. inaequalis colonizes the subcuticular host environment, where it develops specialized infection structures called runner hyphae and stromata. These structures are thought to be involved in nutrient acquisition and effector (virulence factor) delivery, but also give rise to conidia that further the infection cycle. Despite their importance, very little is known about how these structures are differentiated. Likewise, nothing is known about how these structures are protected from host defenses or recognition by the host immune system. To better understand these processes, we first performed a glycosidic linkage analysis of sporulating tubular hyphae from V. inaequalis developed in culture. This analysis revealed that the V. inaequalis cell wall is mostly composed of glucans (44%) and mannans (37%), whereas chitin represents a much smaller proportion (4%). Next, we used transcriptomics and confocal laser scanning microscopy to provide insights into the cell wall carbohydrate composition of runner hyphae and stromata. These analyses revealed that, during subcuticular host colonization, genes of V. inaequalis putatively associated with the biosynthesis of immunogenic carbohydrates, such as chitin and β-1,6-glucan, are downregulated relative to growth in culture, while on the surface of runner hyphae and stromata, chitin is deacetylated to the less-immunogenic carbohydrate chitosan. These changes are anticipated to enable the subcuticular differentiation of runner hyphae and stromata by V. inaequalis, as well as to protect these structures from host defenses and recognition by the host immune system. IMPORTANCE Plant-pathogenic fungi are a major threat to food security. Among these are subcuticular pathogens, which often cause latent asymptomatic infections, making them difficult to control. A key feature of these pathogens is their ability to differentiate specialized subcuticular infection structures that, to date, remain largely understudied. This is typified by Venturia inaequalis, which causes scab, the most economically important disease of apples. In this study, we show that, during subcuticular host colonization, V. inaequalis downregulates genes associated with the biosynthesis of two immunogenic cell wall carbohydrates, chitin and β-1,6-glucan, and coats its subcuticular infection structures with a less-immunogenic carbohydrate, chitosan. These changes are anticipated to enable host colonization by V. inaequalis and provide a foundation for understanding subcuticular host colonization by other plant-pathogenic fungi. Such an understanding is important, as it may inform the development of novel control strategies against subcuticular plant-pathogenic fungi.
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Affiliation(s)
- Mercedes Rocafort
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Vaibhav Srivastava
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
| | - Joanna K. Bowen
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, New Zealand
| | - Sara M. Díaz-Moreno
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
| | - Yanan Guo
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Vincent Bulone
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
- School of Food, Agriculture and Wine, The University of Adelaide, Waite Campus, Adelaide, South Australia, Australia
| | - Kim M. Plummer
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, La Trobe University, Bundoora, Melbourne, Victoria, Australia
| | - Paul W. Sutherland
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, New Zealand
| | - Marilyn A. Anderson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Melbourne, Victoria, Australia
| | - Rosie E. Bradshaw
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
| | - 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
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14
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Nualnisachol P, Chumnanpuen P, E-Kobon T. Understanding Snail Mucus Biosynthesis and Shell Biomineralisation through Genomic Data Mining of the Reconstructed Carbohydrate and Glycan Metabolic Pathways of the Giant African Snail ( Achatina fulica). BIOLOGY 2023; 12:836. [PMID: 37372121 DOI: 10.3390/biology12060836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
The giant African snail (Order Stylommatophora: Family Achatinidae), Achatina fulica (Bowdich, 1822), is the most significant and invasive land snail pest. The ecological adaptability of this snail involves high growth rate, reproductive capacity, and shell and mucus production, driven by several biochemical processes and metabolism. The available genomic information for A. fulica provides excellent opportunities to hinder the underlying processes of adaptation, mainly carbohydrate and glycan metabolic pathways toward the shell and mucus formation. The authors analysed the 1.78 Gb draft genomic contigs of A. fulica to identify enzyme-coding genes and reconstruct biochemical pathways related to the carbohydrate and glycan metabolism using a designed bioinformatic workflow. Three hundred and seventy-seven enzymes involved in the carbohydrate and glycan metabolic pathways were identified based on the KEGG pathway reference in combination with protein sequence comparison, structural analysis, and manual curation. Fourteen complete pathways of carbohydrate metabolism and seven complete pathways of glycan metabolism supported the nutrient acquisition and production of the mucus proteoglycans. Increased copy numbers of amylases, cellulases, and chitinases highlighted the snail advantage in food consumption and fast growth rate. The ascorbate biosynthesis pathway identified from the carbohydrate metabolic pathways of A. fulica was involved in the shell biomineralisation process in association with the collagen protein network, carbonic anhydrases, tyrosinases, and several ion transporters. Thus, our bioinformatic workflow was able to reconstruct carbohydrate metabolism, mucus biosynthesis, and shell biomineralisation pathways from the A. fulica genome and transcriptome data. These findings could reveal several evolutionary advantages of the A. fulica snail, and will benefit the discovery of valuable enzymes for industrial and medical applications.
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Affiliation(s)
- Pornpavee Nualnisachol
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
| | - Pramote Chumnanpuen
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
- Department of Zoology, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Teerasak E-Kobon
- Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
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15
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Harris W, Kim S, Vӧlz R, Lee YH. Nuclear effectors of plant pathogens: Distinct strategies to be one step ahead. MOLECULAR PLANT PATHOLOGY 2023; 24:637-650. [PMID: 36942744 DOI: 10.1111/mpp.13315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/17/2023] [Accepted: 02/08/2023] [Indexed: 05/18/2023]
Abstract
Nuclear effector proteins released by bacteria, oomycete, nematode, and fungi burden the global environment and crop yield. Microbial effectors are key weapons in the evolutionary arms race between plants and pathogens, vital in determining the success of pathogenic colonization. Secreted effectors undermine a multitude of host cellular processes depending on their target destination. Effectors are classified by their localization as either extracellular (apoplastic) or intracellular. Intracellular effectors can be further subclassified by their compartment such as the nucleus, cytoplasm or chloroplast. Nuclear effectors bring into question the role of the plant nucleus' intrinsic defence strategies and their vulnerability to effector-based manipulation. Nuclear effectors interfere with multiple nuclear processes including the epigenetic regulation of the host chromatin, the impairment of the trans-kingdom antifungal RNAi machinery, and diverse classes of immunity-associated host proteins. These effector-targeted pathways are widely conserved among different hosts and regulate a broad array of plant cellular processes. Thus, these nuclear sites constitute meaningful targets for effectors to subvert the plant defence system and acquire resources for pathogenic propagation. This review provides an extensive and comparative compilation of diverse plant microbe nuclear effector libraries, thereby highlighting the distinct and conserved mechanisms these effectors employ to modulate plant cellular processes for the pathogen's profit.
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Affiliation(s)
- William Harris
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Seongbeom Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Ronny Vӧlz
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Interdisciplinary Program in Agricultural Genomics, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
- Center for Fungal Genetic Resources, Seoul National University, Seoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
- Plant Immunity Research Center, Seoul National University, Seoul, South Korea
- Center for Plant Microbiome Research, Seoul National University, Seoul, South Korea
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16
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Teulet A, Quan C, Evangelisti E, Wanke A, Yang W, Schornack S. A pathogen effector FOLD diversified in symbiotic fungi. THE NEW PHYTOLOGIST 2023. [PMID: 37257494 DOI: 10.1111/nph.18996] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/27/2023] [Indexed: 06/02/2023]
Abstract
Pathogenic fungi use secreted effector proteins to suppress immunity and support their infection, but effectors have also been reported from fungi that engage in nutritional symbioses with plants. Sequence-based effector comparisons between pathogens and symbiotic arbuscular mycorrhizal (AM) fungi are hampered by the huge diversity of effector sequences even within closely related microbes. To find sequence-divergent but structurally similar effectors shared between symbiotic and pathogenic fungi, we compared secreted protein structure models of the AM fungus Rhizophagus irregularis to known pathogen effectors. We identified proteins with structural similarity to known Fusarium oxysporum f. sp. lycopersici dual domain (FOLD) effectors, which occur in low numbers in several fungal pathogens. Contrastingly, FOLD genes from AM fungi (MycFOLDs) are found in enlarged and diversified gene families with higher levels of positive selection in their C-terminal domains. Our structure model comparison suggests that MycFOLDs are similar to carbohydrate-binding motifs. Different MycFOLD genes are expressed during colonisation of different hosts and MycFOLD-17 transcripts accumulate in plant intracellular arbuscules. The exclusive presence of MycFOLDs across unrelated plant-colonising fungi, their inducible expression, lineage-specific sequence diversification and transcripts in arbuscules suggest that FOLD proteins act as effectors during plant colonisation of symbiotic and pathogenic fungi.
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Affiliation(s)
- Albin Teulet
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | - Clément Quan
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | | | - Alan Wanke
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
| | - Weibing Yang
- Sainsbury Laboratory, University of Cambridge, Cambridge, CB2 1LR, UK
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17
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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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18
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Sun L, Wu X, Diao J, Zhang J. Pathogenesis mechanisms of phytopathogen effectors. WIREs Mech Dis 2023; 15:e1592. [PMID: 36593734 DOI: 10.1002/wsbm.1592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 01/04/2023]
Abstract
Plants commonly face the threat of invasion by a wide variety of pathogens and have developed sophisticated immune mechanisms to defend against infectious diseases. However, successful pathogens have evolved diverse mechanisms to overcome host immunity and cause diseases. Different cell structures and unique cellular organelles carried by plant cells endow plant-specific defense mechanisms, in addition to the common framework of innate immune system shared by both plants and animals. Effectors serve as crucial virulence weapons employed by phytopathogens to disarm the plant immune system and promote infection. Here we summarized the many diverse strategies by which phytopathogen effectors overcome plant defense and prospected future perspectives. This article is categorized under: Infectious Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Lifan Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaoyun Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jian Diao
- Northeast Forestry University, College of Forestry, Harbin, China
| | - Jie Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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19
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Suppression of Chitin-Triggered Immunity by a New Fungal Chitin-Binding Effector Resulting from Alternative Splicing of a Chitin Deacetylase Gene. J Fungi (Basel) 2022; 8:jof8101022. [PMID: 36294587 PMCID: PMC9605236 DOI: 10.3390/jof8101022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/24/2022] [Accepted: 09/25/2022] [Indexed: 11/16/2022] Open
Abstract
Phytopathogenic fungi have evolved mechanisms to manipulate plant defences, such as chitin-triggered immunity, a plant defensive response based on the recognition of chitin oligomers by plant-specific receptors. To cope with chitin resistance, fungal pathogens have developed different strategies to prevent chitin recognition, such as binding, breaking, or modifying immunogenic oligomers. In powdery mildew fungi, the activity of chitin deacetylase (CDA) is crucial for this purpose, since silencing of the CDA gene leads to a rapid activation of chitin signalling and the subsequent suppression of fungal growth. In this work, we have identified an unusually short CDA transcript in Podosphaera xanthii, the cucurbit powdery mildew pathogen. This transcript, designated PxCDA3, appears to encode a truncated version of CDA resulting from an alternative splicing of the PxCDA gene, which lacked most of the chitin deacetylase activity domain but retained the carbohydrate-binding module. Experiments with the recombinant protein showed its ability to bind to chitin oligomers and prevent the activation of chitin signalling. Furthermore, the use of fluorescent fusion proteins allowed its localization in plant papillae at pathogen penetration sites. Our results suggest the occurrence of a new fungal chitin-binding effector, designated CHBE, involved in the manipulation of chitin-triggered immunity in powdery mildew fungi.
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20
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Lü P, Liu Y, Yu X, Shi CL, Liu X. The right microbe-associated molecular patterns for effective recognition by plants. Front Microbiol 2022; 13:1019069. [PMID: 36225366 PMCID: PMC9549324 DOI: 10.3389/fmicb.2022.1019069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Plants are constantly exposed to diverse microbes and thus develop a sophisticated perceive system to distinguish non-self from self and identify non-self as friends or foes. Plants can detect microbes in apoplast via recognition of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) on the cell surface to activate appropriate signaling in response to microbes. MAMPs are highly conserved but essential molecules of microbes and often buried in microbes’ complex structure. Mature MAMPs are released from microbes by invasion-induced hydrolytic enzymes in apoplast and accumulate in proximity of plasma membrane-localized PRRs to be perceived as ligands to activate downstream signaling. In response, microbes developed strategies to counteract these processing. Here, we review how the form, the concentration, and the size of mature MAMPs affect the PRR-mediated immune signaling. In particular, we describe some potential applications and explore potential open questions in the fields.
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Affiliation(s)
- Pengpeng Lü
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, China
| | - Yi Liu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, China
| | - Xixi Yu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, China
- School of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | | | - Xiaokun Liu
- Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, China
- *Correspondence: Xiaokun Liu,
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21
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Ustilaginoidea virens Nuclear Effector SCRE4 Suppresses Rice Immunity via Inhibiting Expression of a Positive Immune Regulator OsARF17. Int J Mol Sci 2022; 23:ijms231810527. [PMID: 36142440 PMCID: PMC9501289 DOI: 10.3390/ijms231810527] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/05/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
Rice false smut caused by the biotrophic fungal pathogen Ustilaginoidea virens has become one of the most important diseases in rice. The large effector repertory in U. virens plays a crucial role in virulence. However, current knowledge of molecular mechanisms how U. virens effectors target rice immune signaling to promote infection is very limited. In this study, we identified and characterized an essential virulence effector, SCRE4 (Secreted Cysteine-Rich Effector 4), in U. virens. SCRE4 was confirmed as a secreted nuclear effector through yeast secretion, translocation assays and protein subcellular localization, as well as up-regulation during infection. The SCRE4 gene deletion attenuated the virulence of U. virens to rice. Consistently, ectopic expression of SCRE4 in rice inhibited chitin-triggered immunity and enhanced susceptibility to false smut, substantiating that SCRE4 is an essential virulence factor. Furthermore, SCRE4 transcriptionally suppressed the expression of OsARF17, an auxin response factor in rice, which positively regulates rice immune responses and resistance against U. virens. Additionally, the immunosuppressive capacity of SCRE4 depended on its nuclear localization. Therefore, we uncovered a virulence strategy in U. virens that transcriptionally suppresses the expression of the immune positive modulator OsARF17 through nucleus-localized effector SCRE4 to facilitate infection.
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22
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Tarallo M, McDougal RL, Chen Z, Wang Y, Bradshaw RE, Mesarich CH. Characterization of two conserved cell death elicitor families from the Dothideomycete fungal pathogens Dothistroma septosporum and Fulvia fulva (syn. Cladosporium fulvum). Front Microbiol 2022; 13:964851. [PMID: 36160260 PMCID: PMC9493481 DOI: 10.3389/fmicb.2022.964851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022] Open
Abstract
Dothistroma septosporum (Ds) and Fulvia fulva (Ff; previously called Cladosporium fulvum) are two closely related Dothideomycete fungal species that cause Dothistroma needle blight in pine and leaf mold in tomato, respectively. During host colonization, these pathogens secrete virulence factors termed effectors to promote infection. In the presence of corresponding host immune receptors, however, these effectors activate plant defenses, including a localized cell death response that halts pathogen growth. We identified two apoplastic effector protein families, Ecp20 and Ecp32, which are conserved between the two pathogens. The Ecp20 family has four paralogues in both species, while the Ecp32 family has four paralogues in D. septosporum and five in F. fulva. Both families have members that are highly expressed during host infection. Members of the Ecp20 family have predicted structural similarity to proteins with a β-barrel fold, including the Alt a 1 allergen from Alternaria alternata, while members of the Ecp32 family have predicted structural similarity to proteins with a β-trefoil fold, such as trypsin inhibitors and lectins. Using Agrobacterium tumefaciens-mediated transient transformation assays, each family member was assessed for its ability to trigger cell death in leaves of the non-host species Nicotiana benthamiana and N. tabacum. Using this approach, FfEcp20-2, DsEcp20-3, and FfEcp20-3 from the Ecp20 family, and all members from the Ecp32 family, except for the Ds/FfEcp32-4 pair, triggered cell death in both species. This cell death was dependent on secretion of the effectors to the apoplast. In line with recognition by an extracellular immune receptor, cell death triggered by Ds/FfEcp20-3 and FfEcp32-3 was compromised in N. benthamiana silenced for BAK1 or SOBIR1, which encode extracellular co-receptors involved in transducing defense response signals following apoplastic effector recognition. We then investigated whether DsEcp20-3 and DsEcp20-4 triggered cell death in the host species Pinus radiata by directly infiltrating purified protein into pine needles. Strikingly, as in the non-host species, DsEcp20-3 triggered cell death, while DsEcp20-4 did not. Collectively, our study describes two new candidate effector families with cell death-eliciting activity from D. septosporum and F. fulva and provides evidence that members of these families are recognized by plant immune receptors.
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Affiliation(s)
- Mariana Tarallo
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | | | - Zhiyuan Chen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Rosie E. Bradshaw
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Carl H. Mesarich
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
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23
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Snelders NC, Rovenich H, Thomma BPHJ. Microbiota manipulation through the secretion of effector proteins is fundamental to the wealth of lifestyles in the fungal kingdom. FEMS Microbiol Rev 2022; 46:fuac022. [PMID: 35604874 PMCID: PMC9438471 DOI: 10.1093/femsre/fuac022] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/19/2022] [Indexed: 11/13/2022] Open
Abstract
Fungi are well-known decomposers of organic matter that thrive in virtually any environment on Earth where they encounter wealths of other microbes. Some fungi evolved symbiotic lifestyles, including pathogens and mutualists, that have mostly been studied in binary interactions with their hosts. However, we now appreciate that such interactions are greatly influenced by the ecological context in which they take place. While establishing their symbioses, fungi not only interact with their hosts but also with the host-associated microbiota. Thus, they target the host and its associated microbiota as a single holobiont. Recent studies have shown that fungal pathogens manipulate the host microbiota by means of secreted effector proteins with selective antimicrobial activity to stimulate disease development. In this review, we discuss the ecological contexts in which such effector-mediated microbiota manipulation is relevant for the fungal lifestyle and argue that this is not only relevant for pathogens of plants and animals but also beneficial in virtually any niche where fungi occur. Moreover, we reason that effector-mediated microbiota manipulation likely evolved already in fungal ancestors that encountered microbial competition long before symbiosis with land plants and mammalian animals evolved. Thus, we claim that effector-mediated microbiota manipulation is fundamental to fungal biology.
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Affiliation(s)
- Nick C Snelders
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
- Theoretical Biology & Bioinformatics Group, Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Hanna Rovenich
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
| | - Bart P H J Thomma
- Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
- Cluster of Excellence on Plant Sciences, Institute for Plant Sciences, University of Cologne, D-50674 Cologne, Germany
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24
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Gong Z, Ning N, Li Z, Xie X, Wilson RA, Liu W. Two Magnaporthe appressoria-specific (MAS) proteins, MoMas3 and MoMas5, are required for suppressing host innate immunity and promoting biotrophic growth in rice cells. MOLECULAR PLANT PATHOLOGY 2022; 23:1290-1302. [PMID: 35526236 PMCID: PMC9366069 DOI: 10.1111/mpp.13226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/12/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
In the devastating rice blast fungus Magnaporthe oryzae, six Magnaporthe appressoria-specific (MAS) proteins are encoded by MoGAS1, MoGAS2 and MoMAS3-MoMAS6. MoGAS1 and MoGAS2 were previously characterized as M. oryzae virulence factors; however, the roles of the other four genes are unknown. Here, we found that, although the loss of any MAS gene did not affect appressorial formation or vegetative growth, ∆Momas3 and ∆Momas5 mutant strains (but not the others) were reduced in virulence on susceptible CO-39 rice seedlings. Focusing on ∆Momas3 and ∆Momas5 mutant strains, we found that they could penetrate host leaf surfaces and fill the first infected rice cell but did not spread readily to neighbouring cells, suggesting they were impaired for biotrophic growth. Live-cell imaging of fluorescently labelled MoMas3 and MoMas5 proteins showed that during biotrophy, MoMas3 localized to the apoplastic compartment formed between fungal invasive hyphae and the plant-derived extra-invasive hyphal membrane while MoMas5 localized to the appressoria and the penetration peg. The loss of either MoMAS3 or MoMAS5 resulted in the accumulation of reactive oxygen species (ROS) in infected rice cells, resulting in the triggering of plant defences that inhibited mutant growth in planta. ∆Momas3 and ∆Momas5 biotrophic growth could be remediated by inhibiting host NADPH oxidases and suppressing ROS accumulation. Thus, MoMas3 and MoMas5 are novel virulence factors involved in suppressing host plant innate immunity to promote biotrophic growth.
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Affiliation(s)
- Ziwen Gong
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
- Department of Plant PathologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Na Ning
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
- Key Laboratory of Agricultural MicrobiologyCollege of AgricultureGuizhou UniversityGuiyangChina
| | - Zhiqiang Li
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xin Xie
- Key Laboratory of Agricultural MicrobiologyCollege of AgricultureGuizhou UniversityGuiyangChina
| | - Richard A. Wilson
- Department of Plant PathologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
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25
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Karimi-Jashni M, Maeda K, Yazdanpanah F, de Wit PJGM, Iida Y. An Integrated Omics Approach Uncovers the Novel Effector Ecp20-2 Required for Full Virulence of Cladosporium fulvum on Tomato. Front Microbiol 2022; 13:919809. [PMID: 35865936 PMCID: PMC9294515 DOI: 10.3389/fmicb.2022.919809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/25/2022] [Indexed: 12/14/2022] Open
Abstract
The fungus Cladosporium fulvum causes the leaf mould in tomatoes. During the colonization of the host, it secretes plenty of effector proteins into the plant apoplast to suppress the plant’s immune system. Here, we characterized and functionally analyzed the Ecp20-2 gene of C. fulvum using combined omics approaches. RNA-sequencing of susceptible tomato plants inoculated with C. fulvum race 0WU showed strongly induced expression of the Ecp20-2 gene. Strong upregulation of expression of the Ecp20-2 gene was confirmed by qPCR, and levels were comparable to those of other known effectors of C. fulvum. The Ecp20-2 gene encodes a small secreted protein of 149 amino acids with a predicted signal peptide of 17 amino acids. Mass spectrometry of apoplastic fluids from infected tomato leaves revealed the presence of several peptides originating from the Ecp20-2 protein, indicating that the protein is secreted and likely functions in the apoplast. In the genome of C. fulvum, Ecp20-2 is surrounded by various repetitive elements, but no allelic variation was detected in the coding region of Ecp20-2 among 120 C. fulvum isolates collected in Japan. Δecp20-2 deletion mutants of strain 0WU of C. fulvum showed decreased virulence, supporting that Ecp20-2 is an effector required for full virulence of the fungus. Virulence assays confirmed a significant reduction of fungal biomass in plants inoculated with Δecp20-2 mutants compared to those inoculated with wild-type, Δecp20-2-complemented mutants, and ectopic transformants. Sequence similarity analysis showed the presence of Ecp20-2 homologs in the genomes of several Dothideomycete fungi. The Ecp20-2 protein shows the best 3D homology with the PevD1 effector of Verticillium dahliae, which interacts with and inhibits the activity of the pathogenesis-related protein PR5, which is involved in the immunity of several host plants.
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Affiliation(s)
- Mansoor Karimi-Jashni
- Department of Plant Pathology, Tarbiat Modares University, Tehran, Iran
- *Correspondence: Mansoor Karimi-Jashni,
| | - Kazuya Maeda
- Laboratory of Plant Pathology, Setsunan University, Hirakata, Japan
| | - Farzaneh Yazdanpanah
- Department of Cell and Molecular Biology, Shahid Beheshti University, Tehran, Iran
| | | | - Yuichiro Iida
- Laboratory of Plant Pathology, Setsunan University, Hirakata, Japan
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26
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Zhang S, Li C, Si J, Han Z, Chen D. Action Mechanisms of Effectors in Plant-Pathogen Interaction. Int J Mol Sci 2022; 23:6758. [PMID: 35743201 PMCID: PMC9224169 DOI: 10.3390/ijms23126758] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/09/2022] [Accepted: 06/15/2022] [Indexed: 02/08/2023] Open
Abstract
Plant pathogens are one of the main factors hindering the breeding of cash crops. Pathogens, including oomycetes, fungus, and bacteria, secrete effectors as invasion weapons to successfully invade and propagate in host plants. Here, we review recent advances made in the field of plant-pathogen interaction models and the action mechanisms of phytopathogenic effectors. The review illustrates how effectors from different species use similar and distinct strategies to infect host plants. We classify the main action mechanisms of effectors in plant-pathogen interactions according to the infestation process: targeting physical barriers for disruption, creating conditions conducive to infestation, protecting or masking themselves, interfering with host cell physiological activity, and manipulating plant downstream immune responses. The investigation of the functioning of plant pathogen effectors contributes to improved understanding of the molecular mechanisms of plant-pathogen interactions. This understanding has important theoretical value and is of practical significance in plant pathology and disease resistance genetics and breeding.
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Affiliation(s)
| | | | | | - Zhigang Han
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China; (S.Z.); (C.L.); (J.S.)
| | - Donghong Chen
- State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou 311300, China; (S.Z.); (C.L.); (J.S.)
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27
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Kobayashi M, Utsushi H, Fujisaki K, Takeda T, Yamashita T, Terauchi R. A jacalin-like lectin domain-containing protein of Sclerospora graminicola acts as an apoplastic virulence effector in plant-oomycete interactions. MOLECULAR PLANT PATHOLOGY 2022; 23:845-854. [PMID: 35257477 PMCID: PMC9104248 DOI: 10.1111/mpp.13197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
The plant extracellular space, including the apoplast and plasma membrane, is the initial site of plant-pathogen interactions. Pathogens deliver numerous secreted proteins, called effectors, into this region to suppress plant immunity and establish infection. Downy mildew caused by the oomycete pathogen Sclerospora graminicola (Sg) is an economically important disease of Poaceae crops including foxtail millet (Setaria italica). We previously reported the genome sequence of Sg and showed that the jacalin-related lectin (JRL) gene family has significantly expanded in this lineage. However, the biological functions of JRL proteins remained unknown. Here, we show that JRL from Sg (SgJRL) functions as an apoplastic virulence effector. We identified eight SgJRLs by protein mass spectrometry analysis of extracellular fluid from Sg-inoculated foxtail millet leaves. SgJRLs consist of a jacalin-like lectin domain and an N-terminal putative secretion signal; SgJRL expression is induced by Sg infection. Heterologous expression of three SgJRLs with N-terminal secretion signal peptides in Nicotiana benthamiana enhanced the virulence of the pathogen Phytophthora palmivora inoculated onto the same leaves. Of the three SgJRLs, SG06536 fused with green fluorescent protein (GFP) localized to the apoplastic space in N. benthamiana leaves. INF1-mediated induction of defence-related genes was suppressed by co-expression of SG06536-GFP. These findings suggest that JRLs are novel apoplastic effectors that contribute to pathogenicity by suppressing plant defence responses.
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Affiliation(s)
- Michie Kobayashi
- Iwate Biotechnology Research CenterKitakamiIwateJapan
- Present address:
Institute of Agrobiological SciencesNational Agriculture and Food Research Organization (NARO)TsukubaIbarakiJapan
| | - Hiroe Utsushi
- Iwate Biotechnology Research CenterKitakamiIwateJapan
| | - Koki Fujisaki
- Iwate Biotechnology Research CenterKitakamiIwateJapan
| | - Takumi Takeda
- Iwate Biotechnology Research CenterKitakamiIwateJapan
| | | | - Ryohei Terauchi
- Iwate Biotechnology Research CenterKitakamiIwateJapan
- Laboratory of Crop EvolutionGraduate School of AgricultureKyoto UniversityMukoKyotoJapan
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28
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Ngou BPM, Ding P, Jones JDG. Thirty years of resistance: Zig-zag through the plant immune system. THE PLANT CELL 2022; 34:1447-1478. [PMID: 35167697 PMCID: PMC9048904 DOI: 10.1093/plcell/koac041] [Citation(s) in RCA: 295] [Impact Index Per Article: 147.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/02/2022] [Indexed: 05/05/2023]
Abstract
Understanding the plant immune system is crucial for using genetics to protect crops from diseases. Plants resist pathogens via a two-tiered innate immune detection-and-response system. The first plant Resistance (R) gene was cloned in 1992 . Since then, many cell-surface pattern recognition receptors (PRRs) have been identified, and R genes that encode intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) have been cloned. Here, we provide a list of characterized PRRs and NLRs. In addition to immune receptors, many components of immune signaling networks were discovered over the last 30 years. We review the signaling pathways, physiological responses, and molecular regulation of both PRR- and NLR-mediated immunity. Recent studies have reinforced the importance of interactions between the two immune systems. We provide an overview of interactions between PRR- and NLR-mediated immunity, highlighting challenges and perspectives for future research.
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Affiliation(s)
- Bruno Pok Man Ngou
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, UK
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Pingtao Ding
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, UK
- Institute of Biology Leiden, Leiden University, Leiden 2333 BE, The Netherlands
| | - Jonathan D G Jones
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, UK
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29
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Noar RD, Thomas E, Daub ME. Genetic Characteristics and Metabolic Interactions between Pseudocercospora fijiensis and Banana: Progress toward Controlling Black Sigatoka. PLANTS (BASEL, SWITZERLAND) 2022; 11:948. [PMID: 35406928 PMCID: PMC9002641 DOI: 10.3390/plants11070948] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/23/2022] [Accepted: 03/25/2022] [Indexed: 05/10/2023]
Abstract
The international importance of banana and severity of black Sigatoka disease have led to extensive investigations into the genetic characteristics and metabolic interactions between the Dothideomycete Pseudocercospora fijiensis and its banana host. P. fijiensis was shown to have a greatly expanded genome compared to other Dothideomycetes, due to the proliferation of retrotransposons. Genome analysis suggests the presence of dispensable chromosomes that may aid in fungal adaptation as well as pathogenicity. Genomic research has led to the characterization of genes and metabolic pathways involved in pathogenicity, including: secondary metabolism genes such as PKS10-2, genes for mitogen-activated protein kinases such as Fus3 and Slt2, and genes for cell wall proteins such as glucosyl phosphatidylinositol (GPI) and glycophospholipid surface (Gas) proteins. Studies conducted on resistance mechanisms in banana have documented the role of jasmonic acid and ethylene pathways. With the development of banana transformation protocols, strategies for engineering resistance include transgenes expressing antimicrobial peptides or hydrolytic enzymes as well as host-induced gene silencing (HIGS) targeting pathogenicity genes. Pseudocercospora fijiensis has been identified as having high evolutionary potential, given its large genome size, ability to reproduce both sexually and asexually, and long-distance spore dispersal. Thus, multiple control measures are needed for the sustainable control of black Sigatoka disease.
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Affiliation(s)
- Roslyn D. Noar
- NSF Center for Integrated Pest Management, North Carolina State University, Raleigh, NC 27606, USA
| | - Elizabeth Thomas
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; (E.T.); (M.E.D.)
| | - Margaret E. Daub
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA; (E.T.); (M.E.D.)
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30
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Wang Y, Pruitt RN, Nürnberger T, Wang Y. Evasion of plant immunity by microbial pathogens. Nat Rev Microbiol 2022; 20:449-464. [PMID: 35296800 DOI: 10.1038/s41579-022-00710-3] [Citation(s) in RCA: 135] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2022] [Indexed: 12/21/2022]
Abstract
Plant pathogenic viruses, bacteria, fungi and oomycetes cause destructive diseases in natural habitats and agricultural settings, thereby threatening plant biodiversity and global food security. The capability of plants to sense and respond to microbial infection determines the outcome of plant-microorganism interactions. Host-adapted microbial pathogens exploit various infection strategies to evade or counter plant immunity and eventually establish a replicative niche. Evasion of plant immunity through dampening host recognition or the subsequent immune signalling and defence execution is a crucial infection strategy used by different microbial pathogens to cause diseases, underpinning a substantial obstacle for efficient deployment of host genetic resistance genes for sustainable disease control. In this Review, we discuss current knowledge of the varied strategies microbial pathogens use to evade the complicated network of plant immunity for successful infection. In addition, we discuss how to exploit this knowledge to engineer crop resistance.
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Affiliation(s)
- Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China.,The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China
| | - Rory N Pruitt
- Centre for Molecular Biology of Plants (ZMBP), University of Tübingen, Tübingen, Germany
| | - Thorsten Nürnberger
- Centre for Molecular Biology of Plants (ZMBP), University of Tübingen, Tübingen, Germany.,Department of Biochemistry, University of Johannesburg, Johannesburg, South Africa
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China. .,The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, China.
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Santos MDL, de Resende MLV, dos Santos Ciscon BA, Freitas NC, Pereira MHDB, Reichel T, Mathioni SM. LysM receptors in Coffea arabica: Identification, characterization, and gene expression in response to Hemileia vastatrix. PLoS One 2022; 17:e0258838. [PMID: 35143519 PMCID: PMC8830669 DOI: 10.1371/journal.pone.0258838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/28/2022] [Indexed: 11/24/2022] Open
Abstract
Pathogen‐associated molecular patterns (PAMPs) are recognized by pattern recognition receptors (PRRs) localized on the host plasma membrane. These receptors activate a broad-spectrum and durable defense, which are desired characteristics for disease resistance in plant breeding programs. In this study, candidate sequences for PRRs with lysin motifs (LysM) were investigated in the Coffea arabica genome. For this, approaches based on the principle of sequence similarity, conservation of motifs and domains, phylogenetic analysis, and modulation of gene expression in response to Hemileia vastatrix were used. The candidate sequences for PRRs in C. arabica (Ca1-LYP, Ca2-LYP, Ca1-CERK1, Ca2-CERK1, Ca-LYK4, Ca1-LYK5 and Ca2-LYK5) showed high similarity with the reference PRRs used: Os-CEBiP, At-CERK1, At-LYK4 and At-LYK5. Moreover, the ectodomains of these sequences showed high identity or similarity with the reference sequences, indicating structural and functional conservation. The studied sequences are also phylogenetically related to the reference PRRs described in Arabidopsis, rice, and other plant species. All candidates for receptors had their expression induced after the inoculation with H. vastatrix, since the first time of sampling at 6 hours post‐inoculation (hpi). At 24 hpi, there was a significant increase in expression, for most of the receptors evaluated, and at 48 hpi, a suppression. The results showed that the candidate sequences for PRRs in the C. arabica genome display high homology with fungal PRRs already described in the literature. Besides, they respond to pathogen inoculation and seem to be involved in the perception or signaling of fungal chitin, acting as receptors or co-receptors of this molecule. These findings represent an advance in the understanding of the basal immunity of this species.
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Affiliation(s)
- Mariana de Lima Santos
- Programa de Pós-graduação em Biotecnologia Vegetal, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
- * E-mail: (MLS); (MLVR)
| | | | | | - Natália Chagas Freitas
- Departamento de Fitopatologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | | | - Tharyn Reichel
- Departamento de Fitopatologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Sandra Marisa Mathioni
- Departamento de Fitopatologia, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
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32
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N-Acetylglucosamine Sensing and Metabolic Engineering for Attenuating Human and Plant Pathogens. Bioengineering (Basel) 2022; 9:bioengineering9020064. [PMID: 35200417 PMCID: PMC8869657 DOI: 10.3390/bioengineering9020064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/22/2022] [Accepted: 02/03/2022] [Indexed: 11/17/2022] Open
Abstract
During evolution, both human and plant pathogens have evolved to utilize a diverse range of carbon sources. N-acetylglucosamine (GlcNAc), an amino sugar, is one of the major carbon sources utilized by several human and phytopathogens. GlcNAc regulates the expression of many virulence genes of pathogens. In fact, GlcNAc catabolism is also involved in the regulation of virulence and pathogenesis of various human pathogens, including Candida albicans, Vibrio cholerae, Leishmania donovani, Mycobacterium, and phytopathogens such as Magnaporthe oryzae. Moreover, GlcNAc is also a well-known structural component of many bacterial and fungal pathogen cell walls, suggesting its possible role in cell signaling. Over the last few decades, many studies have been performed to study GlcNAc sensing, signaling, and metabolism to better understand the GlcNAc roles in pathogenesis in order to identify new drug targets. In this review, we provide recent insights into GlcNAc-mediated cell signaling and pathogenesis. Further, we describe how the GlcNAc metabolic pathway can be targeted to reduce the pathogens’ virulence in order to control the disease prevalence and crop productivity.
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33
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Huang H, Zhang X, Zhang Y, Yi G, Xie J, Viljoen A, Wang W, Mostert D, Fu G, Peng C, Xiang D, Li C, Liu S. FocECM33, a GPI-anchored protein, regulates vegetative growth and virulence in Fusarium oxysporum f. sp. cubense tropical race 4. Fungal Biol 2022; 126:213-223. [DOI: 10.1016/j.funbio.2021.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/21/2021] [Accepted: 12/24/2021] [Indexed: 11/04/2022]
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Garcia-Ceron D, Lowe RGT, McKenna JA, Brain LM, Dawson CS, Clark B, Berkowitz O, Faou P, Whelan J, Bleackley MR, Anderson MA. Extracellular Vesicles from Fusarium graminearum Contain Protein Effectors Expressed during Infection of Corn. J Fungi (Basel) 2021; 7:977. [PMID: 34829264 PMCID: PMC8625442 DOI: 10.3390/jof7110977] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 12/30/2022] Open
Abstract
Fusarium graminearum (Fgr) is a devastating filamentous fungal pathogen that causes diseases in cereals, while producing mycotoxins that are toxic for humans and animals, and render grains unusable. Low efficiency in managing Fgr poses a constant need for identifying novel control mechanisms. Evidence that fungal extracellular vesicles (EVs) from pathogenic yeast have a role in human disease led us to question whether this is also true for fungal plant pathogens. We separated EVs from Fgr and performed a proteomic analysis to determine if EVs carry proteins with potential roles in pathogenesis. We revealed that protein effectors, which are crucial for fungal virulence, were detected in EV preparations and some of them did not contain predicted secretion signals. Furthermore, a transcriptomic analysis of corn (Zea mays) plants infected by Fgr revealed that the genes of some of the effectors were highly expressed in vivo, suggesting that the Fgr EVs are a mechanism for the unconventional secretion of effectors and virulence factors. Our results expand the knowledge on fungal EVs in plant pathogenesis and cross-kingdom communication, and may contribute to the discovery of new antifungals.
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Affiliation(s)
- Donovan Garcia-Ceron
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
| | - Rohan G. T. Lowe
- La Trobe Comprehensive Proteomics Platform, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (R.G.T.L.); (P.F.)
| | - James A. McKenna
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
| | - Linda M. Brain
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
| | - Charlotte S. Dawson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
- Cambridge Centre for Proteomics, MRC Toxicology Unit, University of Cambridge, Cambridge CB2 1TN, UK
| | - Bethany Clark
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley 6102, Australia;
| | - Oliver Berkowitz
- Department of Animal, Plant and Soil Science, La Trobe Institute for Agriculture and Food, La Trobe University, Bundoora 3086, Australia; (O.B.); (J.W.)
| | - Pierre Faou
- La Trobe Comprehensive Proteomics Platform, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (R.G.T.L.); (P.F.)
| | - James Whelan
- Department of Animal, Plant and Soil Science, La Trobe Institute for Agriculture and Food, La Trobe University, Bundoora 3086, Australia; (O.B.); (J.W.)
| | - Mark R. Bleackley
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
| | - Marilyn A. Anderson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3086, Australia; (D.G.-C.); (J.A.M.); (L.M.B.); (C.S.D.); (M.R.B.)
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35
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Tariqjaveed M, Mateen A, Wang S, Qiu S, Zheng X, Zhang J, Bhadauria V, Sun W. Versatile effectors of phytopathogenic fungi target host immunity. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:1856-1873. [PMID: 34383388 DOI: 10.1111/jipb.13162] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Phytopathogenic fungi secrete a large arsenal of effector molecules, including proteinaceous effectors, small RNAs, phytohormones and derivatives thereof. The pathogenicity of fungal pathogens is primarily determined by these effectors that are secreted into host cells to undermine innate immunity, as well as to facilitate the acquisition of nutrients for their in planta growth and proliferation. After conventional and non-conventional secretion, fungal effectors are translocated into different subcellular compartments of the host cells to interfere with various biological processes. In extracellular spaces, apoplastic effectors cope with physical and chemical barriers to break the first line of plant defenses. Intracellular effectors target essential immune components on the plasma membrane, in the cytosol, including cytosolic organelles, and in the nucleus to suppress host immunity and reprogram host physiology, favoring pathogen colonization. In this review, we comprehensively summarize the recent advances in fungal effector biology, with a focus on the versatile virulence functions of fungal effectors in promoting pathogen infection and colonization. A perspective of future research on fungal effector biology is also discussed.
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Affiliation(s)
- Muhammad Tariqjaveed
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Abdul Mateen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Shanzhi Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Shanshan Qiu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Xinhang Zheng
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
| | - Jie Zhang
- Institute of Microbiology, The Chinese Academy of Sciences, Beijing, 100101, China
| | - Vijai Bhadauria
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
| | - Wenxian Sun
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, 100193, China
- The Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, China Agricultural University, Beijing, 100193, China
- Department of Plant Pathology, College of Plant Protection, Jilin Agricultural University, Changchun, 130118, China
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36
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Hunziker L, Tarallo M, Gough K, Guo M, Hargreaves C, Loo TS, McDougal RL, Mesarich CH, Bradshaw RE. Apoplastic effector candidates of a foliar forest pathogen trigger cell death in host and non-host plants. Sci Rep 2021; 11:19958. [PMID: 34620932 PMCID: PMC8497623 DOI: 10.1038/s41598-021-99415-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/22/2021] [Indexed: 11/23/2022] Open
Abstract
Forests are under threat from pests, pathogens, and changing climate. A major forest pathogen worldwide is the hemibiotroph Dothistroma septosporum, which causes dothistroma needle blight (DNB) of pines. While D. septosporum uses effector proteins to facilitate host infection, it is currently unclear whether any of these effectors are recognised by immune receptors to activate the host immune system. Such information is needed to identify and select disease resistance against D. septosporum in pines. We predicted and investigated apoplastic D. septosporum candidate effectors (DsCEs) using bioinformatics and plant-based experiments. We discovered DsCEs that trigger cell death in the angiosperm Nicotiana spp., indicative of a hypersensitive defence response and suggesting their recognition by immune receptors in non-host plants. In a first for foliar forest pathogens, we developed a novel protein infiltration method to show that tissue-cultured pine shoots can respond with a cell death response to a DsCE, as well as to a reference cell death-inducing protein. The conservation of responses across plant taxa suggests that knowledge of pathogen-angiosperm interactions may also be relevant to pathogen-gymnosperm interactions. These results contribute to our understanding of forest pathogens and may ultimately provide clues to disease immunity in both commercial and natural forests.
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Affiliation(s)
- Lukas Hunziker
- Centre for Crop and Disease Management, Curtin University, Bentley, Perth, 6102, Australia
| | - Mariana Tarallo
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Keiko Gough
- Scion, New Zealand Forest Research Institute Ltd, Rotorua, 3010, New Zealand
| | - Melissa Guo
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Cathy Hargreaves
- Scion, New Zealand Forest Research Institute Ltd, Rotorua, 3010, New Zealand
| | - Trevor S Loo
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand
| | - Rebecca L McDougal
- Scion, New Zealand Forest Research Institute Ltd, Rotorua, 3010, New Zealand
| | - Carl H Mesarich
- Bio-Protection Research Centre, School of Agriculture and Environment, Massey University, Palmerston North, 4474, New Zealand
| | - Rosie E Bradshaw
- Bio-Protection Research Centre, School of Fundamental Sciences, Massey University, Palmerston North, 4474, New Zealand.
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The Role of Glycoside Hydrolases in Phytopathogenic Fungi and Oomycetes Virulence. Int J Mol Sci 2021; 22:ijms22179359. [PMID: 34502268 PMCID: PMC8431085 DOI: 10.3390/ijms22179359] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 01/11/2023] Open
Abstract
Phytopathogenic fungi need to secrete different hydrolytic enzymes to break down complex polysaccharides in the plant cell wall in order to enter the host and develop the disease. Fungi produce various types of cell wall degrading enzymes (CWDEs) during infection. Most of the characterized CWDEs belong to glycoside hydrolases (GHs). These enzymes hydrolyze glycosidic bonds and have been identified in many fungal species sequenced to date. Many studies have shown that CWDEs belong to several GH families and play significant roles in the invasion and pathogenicity of fungi and oomycetes during infection on the plant host, but their mode of function in virulence is not yet fully understood. Moreover, some of the CWDEs that belong to different GH families act as pathogen-associated molecular patterns (PAMPs), which trigger plant immune responses. In this review, we summarize the most important GHs that have been described in eukaryotic phytopathogens and are involved in the establishment of a successful infection.
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Buscaill P, van der Hoorn RAL. Defeated by the nines: nine extracellular strategies to avoid microbe-associated molecular patterns recognition in plants. THE PLANT CELL 2021; 33:2116-2130. [PMID: 33871653 PMCID: PMC8364246 DOI: 10.1093/plcell/koab109] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 04/07/2021] [Indexed: 05/13/2023]
Abstract
Recognition of microbe-associated molecular patterns (MAMPs) by cell-surface receptors is pivotal in host-microbe interactions. Both pathogens and symbionts establish plant-microbe interactions using fascinating intricate extracellular strategies to avoid recognition. Here we distinguish nine different extracellular strategies to avoid recognition by the host, acting at three different levels. To avoid the accumulation of MAMP precursors (Level 1), microbes take advantage of polymorphisms in both MAMP proteins and glycans, or downregulate MAMP production. To reduce hydrolytic MAMP release (Level 2), microbes shield MAMP precursors with proteins or glycans and inhibit or degrade host-derived hydrolases. And to prevent MAMP perception directly (Level 3), microbes degrade or sequester MAMPs before they are perceived. We discuss examples of these nine strategies and envisage three additional extracellular strategies to avoid MAMP perception in plants.
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Affiliation(s)
- Pierre Buscaill
- The Plant Chemetics Laboratory, Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, UK
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Li GB, Fan J, Wu JL, He JX, Liu J, Shen S, Gishkori ZGN, Hu XH, Zhu Y, Zhou SX, Ji YP, Pu M, Zhao JH, Zhao ZX, Wang H, Zhang JW, Huang YY, Li Y, Huang F, Wang WM. The Flower-Infecting Fungus Ustilaginoidea virens Subverts Plant Immunity by Secreting a Chitin-Binding Protein. FRONTIERS IN PLANT SCIENCE 2021; 12:733245. [PMID: 34421978 PMCID: PMC8377610 DOI: 10.3389/fpls.2021.733245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Ustilaginoidea virens is a biotrophic fungal pathogen specifically colonizing rice floral organ and causes false smut disease of rice. This disease has emerged as a serious problem that hinders the application of high-yield rice cultivars, by reducing grain yield and quality as well as introducing mycotoxins. However, the pathogenic mechanisms of U. virens are still enigmatic. Here we demonstrate that U. virens employs a secreted protein UvCBP1 to manipulate plant immunity. In planta expression of UvCBP1 led to compromised chitin-induced defense responses in Arabidopsis and rice, including burst of reactive oxygen species (ROS), callose deposition, and expression of defense-related genes. In vitro-purified UvCBP1 protein competes with rice chitin receptor OsCEBiP to bind to free chitin, thus impairing chitin-triggered rice immunity. Moreover, UvCBP1 could significantly promote infection of U. virens in rice flowers. Our results uncover a mechanism of a floral fungus suppressing plant immunity and pinpoint a universal role of chitin-battlefield during plant-fungi interactions.
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40
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Quo vadis: signaling molecules and small secreted proteins from mycorrhizal fungi at the early stage of mycorrhiza formation. Symbiosis 2021. [DOI: 10.1007/s13199-021-00793-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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41
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Shao D, Smith DL, Kabbage M, Roth MG. Effectors of Plant Necrotrophic Fungi. FRONTIERS IN PLANT SCIENCE 2021; 12:687713. [PMID: 34149788 PMCID: PMC8213389 DOI: 10.3389/fpls.2021.687713] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/03/2021] [Indexed: 05/20/2023]
Abstract
Plant diseases caused by necrotrophic fungal pathogens result in large economic losses in field crop production worldwide. Effectors are important players of plant-pathogen interaction and deployed by pathogens to facilitate plant colonization and nutrient acquisition. Compared to biotrophic and hemibiotrophic fungal pathogens, effector biology is poorly understood for necrotrophic fungal pathogens. Recent bioinformatics advances have accelerated the prediction and discovery of effectors from necrotrophic fungi, and their functional context is currently being clarified. In this review we examine effectors utilized by necrotrophic fungi and hemibiotrophic fungi in the latter stages of disease development, including plant cell death manipulation. We define "effectors" as secreted proteins and other molecules that affect plant physiology in ways that contribute to disease establishment and progression. Studying and understanding the mechanisms of necrotrophic effectors is critical for identifying avenues of genetic intervention that could lead to improved resistance to these pathogens in plants.
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Affiliation(s)
| | | | | | - Mitchell G. Roth
- Department of Plant Pathology, University of Wisconsin – Madison, Madison, WI, United States
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42
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Tian H, MacKenzie CI, Rodriguez‐Moreno L, van den Berg GCM, Chen H, Rudd JJ, Mesters JR, Thomma BPHJ. Three LysM effectors of Zymoseptoria tritici collectively disarm chitin-triggered plant immunity. MOLECULAR PLANT PATHOLOGY 2021; 22:683-693. [PMID: 33797163 PMCID: PMC8126183 DOI: 10.1111/mpp.13055] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 02/24/2021] [Accepted: 03/03/2021] [Indexed: 05/09/2023]
Abstract
Chitin is a major structural component of fungal cell walls and acts as a microbe-associated molecular pattern (MAMP) that, on recognition by a plant host, triggers the activation of immune responses. To avoid the activation of these responses, the Septoria tritici blotch (STB) pathogen of wheat, Zymoseptoria tritici, secretes LysM effector proteins. Previously, the LysM effectors Mg1LysM and Mg3LysM were shown to protect fungal hyphae against host chitinases. Furthermore, Mg3LysM, but not Mg1LysM, was shown to suppress chitin-induced reactive oxygen species (ROS) production. Whereas initially a third LysM effector gene was disregarded as a presumed pseudogene, we now provide functional data to show that this gene also encodes a LysM effector, named Mgx1LysM, that is functional during wheat colonization. While Mg3LysM confers a major contribution to Z. tritici virulence, Mgx1LysM and Mg1LysM contribute to Z. tritici virulence with smaller effects. All three LysM effectors display partial functional redundancy. We furthermore demonstrate that Mgx1LysM binds chitin, suppresses the chitin-induced ROS burst, and is able to protect fungal hyphae against chitinase hydrolysis. Finally, we demonstrate that Mgx1LysM is able to undergo chitin-induced polymerization. Collectively, our data show that Z. tritici utilizes three LysM effectors to disarm chitin-triggered wheat immunity.
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Affiliation(s)
- Hui Tian
- Laboratory of PhytopathologyWageningen University and ResearchWageningenNetherlands
- Institute for Plant SciencesCluster of Excellence on Plant Sciences (CEPLAS)University of CologneCologneGermany
| | - Craig I. MacKenzie
- Laboratory of PhytopathologyWageningen University and ResearchWageningenNetherlands
| | - Luis Rodriguez‐Moreno
- Laboratory of PhytopathologyWageningen University and ResearchWageningenNetherlands
- Departamento de Biología Celular, Genética y FisiologíaUniversidad de MálagaMálagaSpain
| | | | - Hongxin Chen
- Department of Bio‐Interactions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Jason J. Rudd
- Department of Bio‐Interactions and Crop ProtectionRothamsted ResearchHarpendenUK
| | | | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen University and ResearchWageningenNetherlands
- Institute for Plant SciencesCluster of Excellence on Plant Sciences (CEPLAS)University of CologneCologneGermany
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43
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Mart Nez-Cruz JS, Romero D, Hierrezuelo JS, Thon M, de Vicente A, P Rez-Garc A A. Effectors with chitinase activity (EWCAs), a family of conserved, secreted fungal chitinases that suppress chitin-triggered immunity. THE PLANT CELL 2021; 33:1319-1340. [PMID: 33793825 DOI: 10.1093/plcell/koab011] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 12/11/2020] [Indexed: 05/23/2023]
Abstract
In plants, chitin-triggered immunity is one of the first lines of defense against fungi, but phytopathogenic fungi have developed different strategies to prevent the recognition of chitin. Obligate biotrophs such as powdery mildew fungi suppress the activation of host responses; however, little is known about how these fungi subvert the immunity elicited by chitin. During epiphytic growth, the cucurbit powdery mildew fungus Podosphaera xanthii expresses a family of candidate effector genes comprising nine members with an unknown function. In this work, we examine the role of these candidates in the infection of melon (Cucumis melo L.) plants, using gene expression analysis, RNAi silencing assays, protein modeling and protein-ligand predictions, enzymatic assays, and protein localization studies. Our results show that these proteins are chitinases that are released at pathogen penetration sites to break down immunogenic chitin oligomers, thus preventing the activation of chitin-triggered immunity. In addition, these effectors, designated effectors with chitinase activity (EWCAs), are widely distributed in pathogenic fungi. Our findings reveal a mechanism by which fungi suppress plant immunity and reinforce the idea that preventing the perception of chitin by the host is mandatory for survival and development of fungi in plant environments.
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Affiliation(s)
- Jes S Mart Nez-Cruz
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Diego Romero
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Jes S Hierrezuelo
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Michael Thon
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Salamanca 37185, Spain
| | - Antonio de Vicente
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Alejandro P Rez-Garc A
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
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44
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Polonio Á, Fernández‐Ortuño D, de Vicente A, Pérez‐García A. A haustorial-expressed lytic polysaccharide monooxygenase from the cucurbit powdery mildew pathogen Podosphaera xanthii contributes to the suppression of chitin-triggered immunity. MOLECULAR PLANT PATHOLOGY 2021; 22:580-601. [PMID: 33742545 PMCID: PMC8035642 DOI: 10.1111/mpp.13045] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 05/06/2023]
Abstract
Podosphaera xanthii is the main causal agent of cucurbit powdery mildew and a limiting factor of crop productivity. The lifestyle of this fungus is determined by the development of specialized parasitic structures inside epidermal cells, termed haustoria, that are responsible for the acquisition of nutrients and the release of effectors. A typical function of fungal effectors is the manipulation of host immunity, for example the suppression of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). Chitin is a major component of fungal cell walls, and chitin oligosaccharides are well-known PAMP elicitors. In this work, we examined the role of PHEC27213, the most highly expressed, haustorium-specific effector candidate of P. xanthii. According to different computational predictions, the protein folding of PHEC27213 was similar to that of lytic polysaccharide monooxygenases (LPMOs) and included a conserved histidine brace; however, PHEC27213 had low sequence similarity with LPMO proteins and displayed a putative chitin-binding domain that was different from the canonical carbohydrate-binding module. Binding and enzymatic assays demonstrated that PHEC27213 was able to bind and catalyse colloidal chitin, as well as chitooligosaccharides, acting as an LPMO. Furthermore, RNAi silencing experiments showed the potential of this protein to prevent the activation of chitin-triggered immunity. Moreover, proteins with similar features were found in other haustorium-forming fungal pathogens. Our results suggest that this protein is a new fungal LPMO that catalyses chitooligosaccharides, thus contributing to the suppression of plant immunity during haustorium development. To our knowledge, this is the first mechanism identified in the haustorium to suppress chitin signalling.
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Affiliation(s)
- Álvaro Polonio
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Dolores Fernández‐Ortuño
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Antonio de Vicente
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Alejandro Pérez‐García
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
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45
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Tzelepis G, Dölfors F, Holmquist L, Dixelius C. Plant mitochondria and chloroplasts are targeted by the Rhizoctonia solani RsCRP1 effector. Biochem Biophys Res Commun 2021; 544:86-90. [PMID: 33550013 DOI: 10.1016/j.bbrc.2021.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 01/10/2023]
Abstract
The fungal species Rhizoctonia solani belongs to the Basidiomycota division and is a ubiquitous soil-borne pathogen. It is the main agent of the damping-off disease in seedlings and causes the root and crown rot disease in sugar beets. Plant pathogens deploy small secreted proteins, called effectors, to manipulate plant immunity in order to infect the host. Here, a gene (RsCRP1) encoded a putative effector cysteine-rich protein was cloned, expressed in Cercospora beticola and used for virulence assays. The RsCRP1 gene was highly induced upon the early-infection stage of sugar beet seedlings and disease was promoted. Confocal microscopy demonstrated localization to the chloroplasts and mitochondria upon transient expression of RsCRP1 in leaves of Nicotiana benthamiana. Further, this effector was unable to induce necrosis or to suppress hypersensitive response induced by the Avr4/Cf4 complex in N. benthamiana. Overall, these data indicate that RsCRP1 is a novel effector targeting distinct plant cell organelles in order to facilitate a successful infection at the early stages of the disease development.
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Affiliation(s)
- Georgios Tzelepis
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala Biocenter, Box 7026, SE-750 07, Uppsala, Sweden.
| | - Fredrik Dölfors
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden
| | - Louise Holmquist
- MariboHilleshög Research AB, Säbyholmsvägen 24, S-26191, Landskrona, Sweden
| | - Christina Dixelius
- Swedish University of Agricultural Sciences, Department of Plant Biology, Uppsala BioCenter, Linnean Center for Plant Biology, P.O. Box 7080, S-75007, Uppsala, Sweden
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Chitosan and Chitin Deacetylase Activity Are Necessary for Development and Virulence of Ustilago maydis. mBio 2021; 12:mBio.03419-20. [PMID: 33653886 PMCID: PMC8092297 DOI: 10.1128/mbio.03419-20] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basidiomycete Ustilago maydis causes smut disease in maize, causing substantial losses in world corn production. This nonobligate pathogen penetrates the plant cell wall with the help of appressoria and then establishes an extensive biotrophic interaction, where the hyphae are tightly encased by the plant plasma membrane. The biotrophic fungus Ustilago maydis harbors a chitin deacetylase (CDA) family of six active genes as well as one pseudogene which are differentially expressed during colonization. This includes one secreted soluble CDA (Cda4) and five putatively glycosylphosphatidylinositol (GPI)-anchored CDAs, of which Cda7 belongs to a new class of fungal CDAs. Here, we provide a comprehensive functional study of the entire family. While budding cells of U. maydis showed a discrete pattern of chitosan staining, biotrophic hyphae appeared surrounded by a chitosan layer. We purified all six active CDAs and show their activity on different chitin substrates. Single as well as multiple cda mutants were generated and revealed a virulence defect for mutants lacking cda7. We implicated cda4 in production of the chitosan layer surrounding biotrophic hyphae and demonstrated that the loss of this layer does not reduce virulence. By combining different cda mutations, we detected redundancy as well as specific functions for certain CDAs. Specifically, certain combinations of mutations significantly affected virulence concomitantly with reduced adherence, appressorium formation, penetration, and activation of plant defenses. Attempts to inactivate all seven cda genes simultaneously were unsuccessful, and induced depletion of cda2 in a background lacking the other six cda genes illustrated an essential role of chitosan for cell wall integrity.
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Li D, Li S, Wei S, Sun W. Strategies to Manage Rice Sheath Blight: Lessons from Interactions between Rice and Rhizoctonia solani. RICE (NEW YORK, N.Y.) 2021; 14:21. [PMID: 33630178 PMCID: PMC7907341 DOI: 10.1186/s12284-021-00466-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Rhizoctonia solani is an important phytopathogenic fungus with a wide host range and worldwide distribution. The anastomosis group AG1 IA of R. solani has been identified as the predominant causal agent of rice sheath blight, one of the most devastating diseases of crop plants. As a necrotrophic pathogen, R. solani exhibits many characteristics different from biotrophic and hemi-biotrophic pathogens during co-evolutionary interaction with host plants. Various types of secondary metabolites, carbohydrate-active enzymes, secreted proteins and effectors have been revealed to be essential pathogenicity factors in R. solani. Meanwhile, reactive oxygen species, phytohormone signaling, transcription factors and many other defense-associated genes have been identified to contribute to sheath blight resistance in rice. Here, we summarize the recent advances in studies on molecular interactions between rice and R. solani. Based on knowledge of rice-R. solani interactions and sheath blight resistance QTLs, multiple effective strategies have been developed to generate rice cultivars with enhanced sheath blight resistance.
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Affiliation(s)
- Dayong Li
- College of Plant Protection, Jilin Agricultural University, 2888 Xincheng Street, 130118, Changchun, Jilin, China
| | - Shuai Li
- Department of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, 110866, Shenyang, Liaoning, China
| | - Songhong Wei
- Department of Plant Pathology, College of Plant Protection, Shenyang Agricultural University, 110866, Shenyang, Liaoning, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, 2888 Xincheng Street, 130118, Changchun, Jilin, China.
- Department of Plant Pathology, the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, 100193, Beijing, China.
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48
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Abstract
Plant-colonizing fungi secrete a cocktail of effector proteins during colonization. After secretion, some of these effectors are delivered into plant cells to directly dampen the plant immune system or redirect host processes benefitting fungal growth. Other effectors function in the apoplastic space either as released proteins modulating the activity of plant enzymes associated with plant defense or as proteins bound to the fungal cell wall. For such fungal cell wall-bound effectors, we know particularly little about their molecular function. In this review, we describe effectors that are associated with the fungal cell wall and discuss how they contribute to colonization.
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Affiliation(s)
- Shigeyuki Tanaka
- Department of Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Straße 10, Marburg 35043, Germany
| | - Regine Kahmann
- Department of Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Straße 10, Marburg 35043, Germany
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Wanke A, Malisic M, Wawra S, Zuccaro A. Unraveling the sugar code: the role of microbial extracellular glycans in plant-microbe interactions. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:15-35. [PMID: 32929496 PMCID: PMC7816849 DOI: 10.1093/jxb/eraa414] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/14/2020] [Indexed: 05/14/2023]
Abstract
To defend against microbial invaders but also to establish symbiotic programs, plants need to detect the presence of microbes through the perception of molecular signatures characteristic of a whole class of microbes. Among these molecular signatures, extracellular glycans represent a structurally complex and diverse group of biomolecules that has a pivotal role in the molecular dialog between plants and microbes. Secreted glycans and glycoconjugates such as symbiotic lipochitooligosaccharides or immunosuppressive cyclic β-glucans act as microbial messengers that prepare the ground for host colonization. On the other hand, microbial cell surface glycans are important indicators of microbial presence. They are conserved structures normally exposed and thus accessible for plant hydrolytic enzymes and cell surface receptor proteins. While the immunogenic potential of bacterial cell surface glycoconjugates such as lipopolysaccharides and peptidoglycan has been intensively studied in the past years, perception of cell surface glycans from filamentous microbes such as fungi or oomycetes is still largely unexplored. To date, only few studies have focused on the role of fungal-derived cell surface glycans other than chitin, highlighting a knowledge gap that needs to be addressed. The objective of this review is to give an overview on the biological functions and perception of microbial extracellular glycans, primarily focusing on their recognition and their contribution to plant-microbe interactions.
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Affiliation(s)
- Alan Wanke
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Milena Malisic
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
| | - Stephan Wawra
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
| | - Alga Zuccaro
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
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50
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Han J, Wang X, Wang F, Zhao Z, Li G, Zhu X, Su J, Chen L. The Fungal Effector Avr-Pita Suppresses Innate Immunity by Increasing COX Activity in Rice Mitochondria. RICE (NEW YORK, N.Y.) 2021; 14:12. [PMID: 33443630 PMCID: PMC7809080 DOI: 10.1186/s12284-021-00453-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 01/02/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Avr-Pita was the first effector identified in the blast fungus (Magnaporthe oryzae)-rice (Oryza sativa) pathosystem. However, the molecular mechanism underlying its effects on the host plant has remained a long-standing mystery. RESULTS Here, we report that ectopically expressing Avr-Pita in rice enhances susceptibility to M. oryzae and suppresses pathogen-associated molecular pattern (PAMP)-triggered defense responses. Avr-Pita targets the host mitochondria and interacts with the cytochrome c oxidase (COX) assembly protein OsCOX11, a key regulator of mitochondrial reactive oxygen species (ROS) metabolism in rice. Overexpressing Avr-Pita or OsCOX11 increased COX activity and decreased ROS accumulation triggered by the fungal PAMP chitin. OsCOX11-overexpressing plants showed increased susceptibility to M. oryzae, whereas OsCOX11-knockdown plants showed resistance to M. oryzae. CONCLUSIONS Taken together, these findings suggest that the fungal pathogen M. oryzae delivers the effector Avr-Pita to the host plant, where it enhances COX activity thus decreasing ROS accumulation. Therefore, this effector suppresses host innate immunity by perturbing ROS metabolism in the mitochondria.
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Affiliation(s)
- Jingluan Han
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou, 510642, China
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Xiaoyu Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Fengpin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Zhe Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou, 510642, China
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Gousi Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China
| | - Xiaoyuan Zhu
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China
| | - Jing Su
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.
| | - Letian Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, South China Agricultural University, Guangzhou, 510642, China.
- College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.
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