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Wang C, Han M, Min Y, Hu J, Pan Y, Huang L, Nie J. Colletotrichum fructicola co-opts cytotoxic ribonucleases that antagonize host competitive microorganisms to promote infection. mBio 2024:e0105324. [PMID: 38953357 DOI: 10.1128/mbio.01053-24] [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: 04/06/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024] Open
Abstract
Phytopathogens secrete numerous molecules into the environment to establish a microbial niche and facilitate host infection. The phytopathogenic fungus Colletotrichum fructicola, which causes pear anthracnose, can colonize different plant tissues like leaves and fruits, which are occupied by a diversity of microbes. We speculate that this fungus produces antimicrobial effectors to outcompete host-associated competitive microorganisms. Herein, we identified two secreted ribonucleases, CfRibo1 and CfRibo2, from the C. fructicola secretome. The two ribonucleases both possess ribonuclease activity and showed cytotoxicity in Nicotianan benthamiana without triggering immunity in an enzymatic activity-dependent manner. CfRibo1 and CfRibo2 recombinant proteins exhibited toxicity against Escherichia coli, Saccharomyces cerevisiae, and, importantly, the phyllosphere microorganisms isolated from the pear host. Among these isolated microbial strains, Bacillus altitudinis is a pathogenic bacterium causing pear soft rot. Strikingly, CfRibo1 and CfRibo2 were found to directly antagonize B. altitudinis to facilitate C. fructicola infection. More importantly, CfRibo1 and CfRibo2 functioned as essential virulence factors of C. fructicola in the presence of host-associated microorganisms. Further analysis revealed these two ribonucleases are widely distributed in fungi and are undergoing purifying selection. Our results provide the first evidence of antimicrobial effectors in Colletotrichum fungi and extend the functional diversity of fungal ribonucleases in plant-pest-environment interactions. IMPORTANCE Colletotrichum fructicola is emerging as a devastating pathogenic fungus causing anthracnose in various crops in agriculture, and understanding how this fungus establishes successful infection is of great significance for anthracnose disease management. Fungi are known to produce secreted effectors as weapons to promote virulence. Considerable progress has been made in elucidating how effectors manipulate plant immunity; however, their importance in modulating environmental microbes is frequently neglected. The present study identified two secreted ribonucleases, CfRibo1 and CfRibo2, as antimicrobial effectors of C. fructicola. These two proteins both possess toxicity to pear phyllosphere microorganisms, and they efficiently antagonize competitive microbes to facilitate the infection of pear hosts. This study represents the first evidence of antimicrobial effectors in Colletotrichum fungi, and we consider that CfRibo1 and CfRibo2 could be targeted for anthracnose disease management in diverse crops in the future.
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Affiliation(s)
- Chunhao Wang
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Mengqing Han
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Yanyan Min
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Jiayi Hu
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Yuemin Pan
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Lili Huang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling, Shaanxi, China
| | - Jiajun Nie
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
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2
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Zambounis A, Boutsika A, Gray N, Hossain M, Chatzidimopoulos M, Tsitsigiannis DI, Paplomatas E, Hane J. Pan-genome survey of Septoria pistaciarum, causal agent of Septoria leaf spot of pistachios, across three Aegean sub-regions of Greece. Front Microbiol 2024; 15:1396760. [PMID: 38919498 PMCID: PMC11196620 DOI: 10.3389/fmicb.2024.1396760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 05/20/2024] [Indexed: 06/27/2024] Open
Abstract
Septoria pistaciarum, a causal agent of Septoria leaf spot disease of pistachio, is a fungal pathogen that causes substantial losses in the cultivation, worldwide. This study describes the first pan-genome-based survey of this phytopathogen-comprising a total of 27 isolates, with 9 isolates each from 3 regional units of Greece (Pieria, Larissa and Fthiotida). The reference isolate (SPF8) assembled into a total of 43.1 Mb, with 38.6% contained within AT-rich regions of approximately 37.5% G:C. The genomes of the 27 isolates exhibited on average 42% gene-coding and 20% repetitive regions. The genomes of isolates from the southern Fthiotida region appeared to more diverged from each other than the other regions based on SNP-derived trees, and also contained isolates similar to both the Pieria and Larissa regions. In contrast, isolates of the Pieria and Larissa were less diverse and distinct from one another. Asexual reproduction appeared to be typical, with no MAT1-2 locus detected in any isolate. Genome-based prediction of infection mode indicated hemibiotrophic and saprotrophic adaptations, consistent with its long latent phase. Gene prediction and orthology clustering generated a pan-genome-wide gene set of 21,174 loci. A total of 59 ortholog groups were predicted to contain candidate effector proteins, with 36 (61%) of these either having homologs to known effectors from other species or could be assigned predicted functions from matches to conserved domains. Overall, effector prediction suggests that S. pistaciarum employs a combination of defensive effectors with roles in suppression of host defenses, and offensive effectors with a range of cytotoxic activities. Some effector-like ortholog groups presented as divergent versions of the same protein, suggesting region-specific adaptations may have occurred. These findings provide insights and future research directions in uncovering the pathogenesis and population dynamics of S. pistaciarum toward the efficient management of Septoria leaf spot of pistachio.
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Affiliation(s)
- Antonios Zambounis
- Hellenic Agricultural Organization - DIMITRA (ELGO - DIMITRA), Institute of Plant Breeding and Genetic Resources, Thessaloniki, Greece
| | - Anastasia Boutsika
- Hellenic Agricultural Organization - DIMITRA (ELGO - DIMITRA), Institute of Plant Breeding and Genetic Resources, Thessaloniki, Greece
| | - Naomi Gray
- Centre for Crop and Disease Management, Department of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Mohitul Hossain
- Centre for Crop and Disease Management, Department of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Michael Chatzidimopoulos
- Laboratory of Plant Pathology, Department of Agriculture, International Hellenic University, Thessaloniki, Greece
| | - Dimitrios I. Tsitsigiannis
- Laboratory of Plant Pathology, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - Epaminondas Paplomatas
- Laboratory of Plant Pathology, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - James Hane
- Centre for Crop and Disease Management, Department of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
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Kumakura N, Singkaravanit-Ogawa S, Gan P, Tsushima A, Ishihama N, Watanabe S, Seo M, Iwasaki S, Narusaka M, Narusaka Y, Takano Y, Shirasu K. Guanosine-specific single-stranded ribonuclease effectors of a phytopathogenic fungus potentiate host immune responses. THE NEW PHYTOLOGIST 2024; 242:170-191. [PMID: 38348532 DOI: 10.1111/nph.19582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 01/06/2024] [Indexed: 03/08/2024]
Abstract
Plants activate immunity upon recognition of pathogen-associated molecular patterns. Although phytopathogens have evolved a set of effector proteins to counteract plant immunity, some effectors are perceived by hosts and induce immune responses. Here, we show that two secreted ribonuclease effectors, SRN1 and SRN2, encoded in a phytopathogenic fungus, Colletotrichum orbiculare, induce cell death in a signal peptide- and catalytic residue-dependent manner, when transiently expressed in Nicotiana benthamiana. The pervasive presence of SRN genes across Colletotrichum species suggested the conserved roles. Using a transient gene expression system in cucumber (Cucumis sativus), an original host of C. orbiculare, we show that SRN1 and SRN2 potentiate host pattern-triggered immunity responses. Consistent with this, C. orbiculare SRN1 and SRN2 deletion mutants exhibited increased virulence on the host. In vitro analysis revealed that SRN1 specifically cleaves single-stranded RNAs at guanosine, leaving a 3'-end phosphate. Importantly, the potentiation of C. sativus responses by SRN1 and SRN2, present in the apoplast, depends on ribonuclease catalytic residues. We propose that the pathogen-derived apoplastic guanosine-specific single-stranded endoribonucleases lead to immunity potentiation in plants.
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Affiliation(s)
- Naoyoshi Kumakura
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | | | - Pamela Gan
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Ayako Tsushima
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Nobuaki Ishihama
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Shunsuke Watanabe
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
| | - Mitsunori Seo
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Tropical Biosphere Research Center, University of the Ryukyus, Nakagami, Okinawa, 903-0213, Japan
| | - Shintaro Iwasaki
- RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
- Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
| | - Mari Narusaka
- Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, Research Institute for Biological Sciences, Kaga, Okayama, 716-1241, Japan
| | - Yoshihiro Narusaka
- Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, Research Institute for Biological Sciences, Kaga, Okayama, 716-1241, Japan
| | - Yoshitaka Takano
- Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Ken Shirasu
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
- Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
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Christian N, Perlin MH. Plant-endophyte communication: Scaling from molecular mechanisms to ecological outcomes. Mycologia 2024; 116:227-250. [PMID: 38380970 DOI: 10.1080/00275514.2023.2299658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 12/22/2023] [Indexed: 02/22/2024]
Abstract
Diverse communities of fungal endophytes reside in plant tissues, where they affect and are affected by plant physiology and ecology. For these intimate interactions to form and persist, endophytes and their host plants engage in intricate systems of communication. The conversation between fungal endophytes and plant hosts ultimately dictates endophyte community composition and function and has cascading effects on plant health and plant interactions. In this review, we synthesize our current knowledge on the mechanisms and strategies of communication used by endophytic fungi and their plant hosts. We discuss the molecular mechanisms of communication that lead to organ specificity of endophytic communities and distinguish endophytes, pathogens, and saprotrophs. We conclude by offering emerging perspectives on the relevance of plant-endophyte communication to microbial community ecology and plant health and function.
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Affiliation(s)
- Natalie Christian
- Department of Biology, University of Louisville, Louisville, Kentucky 40292
| | - Michael H Perlin
- Department of Biology, University of Louisville, Louisville, Kentucky 40292
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5
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Qiu C, Halterman D, Zhang H, Liu Z. Multifunctionality of AsCFEM6 and AsCFEM12 effectors from the potato early blight pathogen Alternaria solani. Int J Biol Macromol 2024; 257:128575. [PMID: 38048930 DOI: 10.1016/j.ijbiomac.2023.128575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/31/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
Plant pathogens secrete fungal-specific common in several fungal extracellular membrane (CFEM) effectors to manipulate host immunity and contribute to their virulence. Little is known about effectors and their functions in Alternaria solani, the necrotrophic fungal pathogen causing potato early blight. To identify candidate CFEM effector genes, we mined A. solani genome databases. This led to the identification of 12 genes encoding CFEM proteins (termed AsCFEM1-AsCFEM12) and 6 of them were confirmed to be putative secreted effectors. In planta expression revealed that AsCFEM6 and AsCFEM12 have elicitor function that triggers plant defense response including cell death in different botanical families. Targeted gene disruption of AsCFEM6 and AsCFEM12 resulted in a change in spore development, significant reduction of virulence on potato and eggplant susceptible cultivars, increased resistance to fungicide stress, variation in iron acquisition and utilization, and the involvement in 1,8-dihydroxynaphthalene (DHN) melanin biosynthesis pathway. Using maximum likelihood method, we found that positive selection likely caused the polymorphism within AsCFEM6 and AsCFEM12 homologs in different Alternaria spp. Site-directed mutagenesis analysis indicated that positive selection sites within their CFEM domains are required for cell death induction in Nicotiana benthamiana and are critical for response to abiotic stress in yeast. These results demonstrate that AsCFEM effectors possess additional functions beyond their roles in host plant immune response and pathogen virulence.
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Affiliation(s)
- Chaodong Qiu
- Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Dennis Halterman
- U.S. Department of Agriculture-Agricultural Research Service, Vegetable Crops Research Unit, Madison, WI 53706, USA
| | - Huajian Zhang
- Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, China; Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei 230036, China.
| | - Zhenyu Liu
- Department of Plant Pathology, School of Plant Protection, Anhui Agricultural University, Hefei, China; Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei 230036, China.
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Ökmen B, Katzy P, Huang L, Wemhöner R, Doehlemann G. A conserved extracellular Ribo1 with broad-spectrum cytotoxic activity enables smut fungi to compete with host-associated bacteria. THE NEW PHYTOLOGIST 2023; 240:1976-1989. [PMID: 37680042 DOI: 10.1111/nph.19244] [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: 07/17/2023] [Accepted: 08/14/2023] [Indexed: 09/09/2023]
Abstract
Ribotoxins are secreted ribonucleases that specifically target and cleave the universally conserved sarcin-ricin loop sequence of rRNA, which leads to inhibition of protein biosynthesis and subsequently to cell death. We have identified and characterized a secreted Ribo1 protein of plant pathogenic smut fungi. Heterologous expression in different model systems showed that smut Ribo1 has cytotoxic activity against bacteria, yeast, host and nonhost plants. Recombinant expression of Ribo1 in Nicotiana benthamiana induced plant cell death; however, an active site mutant induced cell death only when expressed as a secreted protein. In the maize smut Ustilago maydis, transcription of Ribo1 is specifically induced in early infection stages. While a knockout mutant revealed that Ribo1 is dispensable for U. maydis virulence, the overexpression of Ribo1 in planta had a strong dominant negative effect on virulence and induced host defense responses including cell death. Our findings suggest a function of Ribo1 during the epiphytic development rather than for invasive colonization of the host. Accordingly, in the presence of the biocontrol bacteria Pantoea sp., which were isolated from maize leaves, the ribo1 knockout mutant was significantly impaired in virulence. Together, we conclude that Ribo1 enables smut fungi to compete with host-associated bacteria during epiphytic development.
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Affiliation(s)
- Bilal Ökmen
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Center for Molecular Biosciences, 50674, Cologne, Germany
- Department of Microbial Interactions, IMIT/ZMBP, University of Tübingen, 72076, Tübingen, Germany
| | - Philipp Katzy
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Center for Molecular Biosciences, 50674, Cologne, Germany
| | - Luyao Huang
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Center for Molecular Biosciences, 50674, Cologne, Germany
| | - Raphael Wemhöner
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Center for Molecular Biosciences, 50674, Cologne, Germany
| | - Gunther Doehlemann
- Institute for Plant Sciences and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Center for Molecular Biosciences, 50674, Cologne, Germany
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7
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Lin HC, de Ulzurrun GVD, Chen SA, Yang CT, Tay RJ, Iizuka T, Huang TY, Kuo CY, Gonçalves AP, Lin SY, Chang YC, Stajich JE, Schwarz EM, Hsueh YP. Key processes required for the different stages of fungal carnivory by a nematode-trapping fungus. PLoS Biol 2023; 21:e3002400. [PMID: 37988381 PMCID: PMC10662756 DOI: 10.1371/journal.pbio.3002400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 10/24/2023] [Indexed: 11/23/2023] Open
Abstract
Nutritional deprivation triggers a switch from a saprotrophic to predatory lifestyle in soil-dwelling nematode-trapping fungi (NTF). In particular, the NTF Arthrobotrys oligospora secretes food and sex cues to lure nematodes to its mycelium and is triggered to develop specialized trapping devices. Captured nematodes are then invaded and digested by the fungus, thus serving as a food source. In this study, we examined the transcriptomic response of A. oligospora across the stages of sensing, trap development, and digestion upon exposure to the model nematode Caenorhabditis elegans. A. oligospora enacts a dynamic transcriptomic response, especially of protein secretion-related genes, in the presence of prey. Two-thirds of the predicted secretome of A. oligospora was up-regulated in the presence of C. elegans at all time points examined, and among these secreted proteins, 38.5% are predicted to be effector proteins. Furthermore, functional studies disrupting the t-SNARE protein Sso2 resulted in impaired ability to capture nematodes. Additionally, genes of the DUF3129 family, which are expanded in the genomes of several NTF, were highly up-regulated upon nematode exposure. We observed the accumulation of highly expressed DUF3129 proteins in trap cells, leading us to name members of this gene family as Trap Enriched Proteins (TEPs). Gene deletion of the most highly expressed TEP gene, TEP1, impairs the function of traps and prevents the fungus from capturing prey efficiently. In late stages of predation, we observed up-regulation of a variety of proteases, including metalloproteases. Following penetration of nematodes, these metalloproteases facilitate hyphal growth required for colonization of prey. These findings provide insights into the biology of the predatory lifestyle switch in a carnivorous fungus and provide frameworks for other fungal-nematode predator-prey systems.
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Affiliation(s)
- Hung-Che Lin
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | | | - Sheng-An Chen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Ching-Ting Yang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Rebecca J. Tay
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Tomoyo Iizuka
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Tsung-Yu Huang
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Yen Kuo
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - A. Pedro Gonçalves
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Siou-Ying Lin
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
| | - Yu-Chu Chang
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jason E. Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Erich M. Schwarz
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Yen-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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8
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Fones HN, Soanes D, Gurr SJ. Epiphytic proliferation of Zymoseptoria tritici isolates on resistant wheat leaves. Fungal Genet Biol 2023; 168:103822. [PMID: 37343618 DOI: 10.1016/j.fgb.2023.103822] [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: 12/10/2022] [Revised: 06/04/2023] [Accepted: 06/15/2023] [Indexed: 06/23/2023]
Abstract
The wheat pathogen Zymoseptoria tritici is capable of a long period of pre-invasive epiphytic growth. Studies have shown that virulent isolates vary in the extent, duration and growth form of this epiphytic growth, and the fungus has been observed to undergo behaviours such as asexual reproduction by budding and vegetative fusion of hyphae on the leaf surface. This epiphytic colonisation has been investigated very little during interactions in which an isolate of Z. tritici is unable to colonise the apoplast, as occurs during avirulence. However, avirulent isolates have been seen to undergo sexual crosses in the absense of leaf penetration, and it is widely accepted that the main point of distinction between virulent and avirulent isolates occurs at the point of attempted leaf penetration or attempted apoplastic growth, which fails in the avirulent case. In this work, we describe extensive epiphytic growth in three isolates which are unable or have very limited ability to invade the leaf, and show that growth form is as variable as for fully virulent isolates. We demonstrate that during certain interactions, Z. tritici isolates rarely invade the leaf and form pycnidia, but induce necrosis. These isolates are able to achieve higher epiphytic biomass than fully virulent isolates during asymptomatic growth, and may undergo very extensive asexual reproduction on the leaf surface. These findings have implications for open questions such as whether and how Z. tritici obtains nutrients on the leaf surface and the nature of its interaction with wheat defences.
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Affiliation(s)
- H N Fones
- Biosciences, University of Exeter, Exeter, UK
| | - D Soanes
- University of Exeter Medical School, Exeter, UK
| | - S J Gurr
- Biosciences, University of Exeter, Exeter, UK; Department of Biosciences, Utrecht University, Utrecht, the Netherlands.
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9
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Rovenich H, Thomma BPHJ. Battle of the bugs: how an oomycete pathogen shapes the microbiota of its host. THE NEW PHYTOLOGIST 2023; 239:2064-2066. [PMID: 37430388 DOI: 10.1111/nph.19133] [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: 07/12/2023]
Abstract
This article is a Commentary on Gómez‐Pérez et al. (2023), 239: 2320–2334.
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Affiliation(s)
- Hanna Rovenich
- Institute for Plant Sciences, University of Cologne, Zülpicher Straße 47b, 50674, Cologne, Germany
| | - Bart P H J Thomma
- Institute for Plant Sciences, University of Cologne, Zülpicher Straße 47b, 50674, Cologne, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Zülpicher Straße 47b, 50674, Cologne, Germany
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10
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Cao Y, Kümmel F, Logemann E, Gebauer JM, Lawson AW, Yu D, Uthoff M, Keller B, Jirschitzka J, Baumann U, Tsuda K, Chai J, Schulze-Lefert P. Structural polymorphisms within a common powdery mildew effector scaffold as a driver of coevolution with cereal immune receptors. Proc Natl Acad Sci U S A 2023; 120:e2307604120. [PMID: 37523523 PMCID: PMC10410722 DOI: 10.1073/pnas.2307604120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/28/2023] [Indexed: 08/02/2023] Open
Abstract
In plants, host-pathogen coevolution often manifests in reciprocal, adaptive genetic changes through variations in host nucleotide-binding leucine-rich repeat immune receptors (NLRs) and virulence-promoting pathogen effectors. In grass powdery mildew (PM) fungi, an extreme expansion of a RNase-like effector family, termed RALPH, dominates the effector repertoire, with some members recognized as avirulence (AVR) effectors by cereal NLR receptors. We report the structures of the sequence-unrelated barley PM effectors AVRA6, AVRA7, and allelic AVRA10/AVRA22 variants, which are detected by highly sequence-related barley NLRs MLA6, MLA7, MLA10, and MLA22 and of wheat PM AVRPM2 detected by the unrelated wheat NLR PM2. The AVR effectors adopt a common scaffold, which is shared with the RNase T1/F1 family. We found striking variations in the number, position, and length of individual structural elements between RALPH AVRs, which is associated with a differentiation of RALPH effector subfamilies. We show that all RALPH AVRs tested have lost nuclease and synthetase activities of the RNase T1/F1 family and lack significant binding to RNA, implying that their virulence activities are associated with neo-functionalization events. Structure-guided mutagenesis identified six AVRA6 residues that are sufficient to turn a sequence-diverged member of the same RALPH subfamily into an effector specifically detected by MLA6. Similar structure-guided information for AVRA10 and AVRA22 indicates that MLA receptors detect largely distinct effector surface patches. Thus, coupling of sequence and structural polymorphisms within the RALPH scaffold of PMs facilitated escape from NLR recognition and potential acquisition of diverse virulence functions.
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Affiliation(s)
- Yu Cao
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Florian Kümmel
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
| | - Elke Logemann
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
| | - Jan M. Gebauer
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Aaron W. Lawson
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
| | - Dongli Yu
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Matthias Uthoff
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, Zurich8008, Switzerland
| | - Jan Jirschitzka
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Ulrich Baumann
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
| | - Kenichi Tsuda
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Hubei Key Lab of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan430070, China
| | - Jijie Chai
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne50674, Germany
- Westlake Laboratory of Life Sciences and Biomedicine, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou310024, China
- Beijing Frontier Research Center for Biological Structure, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing100084, China
| | - Paul Schulze-Lefert
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
- Cluster of Excellence on Plant Sciences, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
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11
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Yue Y, Deng J, Wang H, Lv T, Dou W, Jiao Y, Peng X, Zhang Y. Two Secretory T2 RNases Act as Cytotoxic Factors Contributing to the Virulence of an Insect Fungal Pathogen. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7069-7081. [PMID: 37122240 DOI: 10.1021/acs.jafc.3c01617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
RNase T2 members are secreted by several pathogens or parasites during infection, playing various roles in pathogen-host interaction. However, functions of those members in biocontrol microbes targeting their hosts are still unknown. Here, we report that an insect fungal pathogen, Beauveria bassiana, produces two secretory RNase T2 members that act as cytotoxic factors, which were examined by insect bioassays using the targeted gene(s) disruption and overexpression strains. Overexpression strains displayed dramatically increased virulence, which was concurrent with few fungal cells and hemocytes in hemocoel, suggesting a cytotoxicity of the overexpressed gene products. In vitro assays using yeast-expressed proteins verified the cytotoxicity of the two members against insect cells, to which the cytotoxic effect was dependent on their RNases enzyme activities and glycosylation modification. Moreover, the excessive humoral immune responses triggered by the two ribonucleases were examined. These results suggested prospects of these two T2 ribonucleases for improvement of biocontrol agents.
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Affiliation(s)
- Yong Yue
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Juan Deng
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Huifang Wang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Ting Lv
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Wei Dou
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Yufei Jiao
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Xinxin Peng
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Yongjun Zhang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
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12
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Wang C, Zheng Y, Liu Z, Qian Y, Li Y, Yang L, Liu S, Liang W, Li J. The secreted FolAsp aspartic protease facilitates the virulence of Fusarium oxysporum f. sp. lycopersici. Front Microbiol 2023; 14:1103418. [PMID: 36760509 PMCID: PMC9905682 DOI: 10.3389/fmicb.2023.1103418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 01/03/2023] [Indexed: 01/26/2023] Open
Abstract
Pathogens utilize secretory effectors to manipulate plant defense. Fusarium oxysporum f. sp. lycopersici (Fol) is the causal agent of Fusarium wilt disease in tomatoes. We previously identified 32 secreted effector candidates by LC-MS analysis. In this study, we functionally identified one of the secreted proteins, FolAsp, which belongs to the aspartic proteases (Asp) family. The FolAsp was upregulated with host root specifically induction. Its N-terminal 1-19 amino acids performed the secretion activity in the yeast system, which supported its secretion in Fol. Phenotypically, the growth and conidia production of the FolAsp deletion mutants were not changed; however, the mutants displayed significantly reduced virulence to the host tomato. Further study revealed the FolAsp was localized at the apoplast and inhibited INF1-induced cell death in planta. Meanwhile, FolAsp could inhibit flg22-mediated ROS burst. Furthermore, FolAsp displayed protease activity on host protein, and overexpression of FolAsp in Fol enhanced pathogen virulence. These results considerably extend our understanding of pathogens utilizing secreted protease to inhibit plant defense and promote its virulence, which provides potential applications for tomato improvement against disease as the new drug target.
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Affiliation(s)
- Chenyang Wang
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Yaning Zheng
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Zhishan Liu
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Yongpan Qian
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Yue Li
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Limei Yang
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China
| | - Sihui Liu
- College of Science and Information, Qingdao Agricultural University, Qingdao, China
| | - Wenxing Liang
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China,*Correspondence: Wenxing Liang,
| | - Jingtao Li
- College of Plant Health and Medicine, Engineering Research Center for Precision Pest Management for Fruits and Vegetables of Qingdao, Shandong Engineering Research Center for Environment-Friendly Agricultural Pest Management, Shandong Province Key Laboratory of Applied Mycology, Qingdao Agricultural University, Qingdao, China,Jingtao Li,
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13
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Emir M, Ozketen AC, Andac Ozketen A, Çelik Oğuz A, Huang M, Karakaya A, Rampitsch C, Gunel A. Increased levels of cell wall degrading enzymes and peptidases are associated with aggressiveness in a virulent isolate of Pyrenophora teres f. maculata. JOURNAL OF PLANT PHYSIOLOGY 2022; 279:153839. [PMID: 36370615 DOI: 10.1016/j.jplph.2022.153839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 09/22/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
Pyrenophora teres f. maculata (Ptm) is a fungal pathogen that causes the spot form of net blotch on barley and leads to economic losses in many of the world's barley-growing regions. Isolates of Ptm exhibit varying levels of aggressiveness that result in quantifiable changes in the severity of the disease. Previous research on plant-pathogen interactions has shown that such divergence is reflected in the proteome and secretome of the pathogen, with certain classes of proteins more prominent in aggressive isolates. Here we have made a detailed comparative analysis of the secretomes of two Ptm isolates, GPS79 and E35 (highly and mildly aggressive, respectively) using a proteomics-based approach. The secretomes were obtained in vitro using media amended with barley leaf sections. Secreted proteins therein were harvested, digested with trypsin, and fractionated offline by HPLC prior to LC-MS in a high-resolution instrument to obtain deep coverage of the proteome. The subsequent analysis used a label-free quantitative proteomics approach with relative quantification of proteins based on precursor ion intensities. A total of 1175 proteins were identified, 931 from Ptm and 244 from barley. Further analysis revealed 160 differentially abundant proteins with at least a two-fold abundance difference between the isolates, with the most enriched in the aggressive GPS79 secretome. These proteins were mainly cell-wall (carbohydrate) degrading enzymes and peptidases, with some oxidoreductases and other pathogenesis-related proteins also identified, suggesting that aggressiveness is associated with an improved ability of GPS79 to overcome cell wall barriers and neutralize host defense responses.
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Affiliation(s)
- Mahmut Emir
- Kirsehir-Ahi Evran University, Faculty of Arts and Sciences, Department of Chemistry, Kirsehir, Turkey
| | | | | | - Arzu Çelik Oğuz
- Ankara University Faculty of Agriculture, Department of Plant Protection, Dışkapı, Ankara, Turkey
| | - Mei Huang
- Agriculture and Agrifood Canada, Morden Research and Development Centre, Morden MB, Canada
| | - Aziz Karakaya
- Ankara University Faculty of Agriculture, Department of Plant Protection, Dışkapı, Ankara, Turkey
| | - Christof Rampitsch
- Agriculture and Agrifood Canada, Morden Research and Development Centre, Morden MB, Canada.
| | - Aslihan Gunel
- Kirsehir-Ahi Evran University, Faculty of Arts and Sciences, Department of Chemistry, Kirsehir, Turkey.
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14
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Todd JNA, Carreón-Anguiano KG, Islas-Flores I, Canto-Canché B. Fungal Effectoromics: A World in Constant Evolution. Int J Mol Sci 2022; 23:13433. [PMID: 36362218 PMCID: PMC9656242 DOI: 10.3390/ijms232113433] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/25/2022] [Accepted: 10/31/2022] [Indexed: 10/28/2023] Open
Abstract
Effectors are small, secreted molecules that mediate the establishment of interactions in nature. While some concepts of effector biology have stood the test of time, this area of study is ever-evolving as new effectors and associated characteristics are being revealed. In the present review, the different characteristics that underly effector classifications are discussed, contrasting past and present knowledge regarding these molecules to foster a more comprehensive understanding of effectors for the reader. Research gaps in effector identification and perspectives for effector application in plant disease management are also presented, with a focus on fungal effectors in the plant-microbe interaction and interactions beyond the plant host. In summary, the review provides an amenable yet thorough introduction to fungal effector biology, presenting noteworthy examples of effectors and effector studies that have shaped our present understanding of the field.
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Affiliation(s)
- Jewel Nicole Anna Todd
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Karla Gisel Carreón-Anguiano
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Ignacio Islas-Flores
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
| | - Blondy Canto-Canché
- Unidad de Biotecnología, Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130 x 32 y 34, Colonia Chuburná de Hidalgo, Mérida C.P. 97205, Yucatán, Mexico
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15
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Welch T, Bayon C, Rudd JJ, Kanyuka K, Kettles GJ. Induction of distinct plant cell death programs by secreted proteins from the wheat pathogen Zymoseptoria tritici. Sci Rep 2022; 12:17880. [PMID: 36284131 PMCID: PMC9596407 DOI: 10.1038/s41598-022-22660-9] [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: 07/18/2022] [Accepted: 10/18/2022] [Indexed: 01/20/2023] Open
Abstract
Cell death processes in eukaryotes shape normal development and responses to the environment. For plant-microbe interactions, initiation of host cell death plays an important role in determining disease outcomes. Cell death pathways are frequently initiated following detection of pathogen-derived molecules which can lead to resistance or susceptibility to disease depending on pathogen lifestyle. We previously identified several small secreted proteins (SSPs) from the wheat-infecting fungus Zymoseptoria tritici that induce rapid cell death in Nicotiana benthamiana following Agrobacterium-mediated delivery and expression (agroinfiltration). Here we investigated whether the execution of host cells was mechanistically similar in response to different Z. tritici SSPs. Using RNA sequencing, we found that transient expression of four Z. tritici SSPs led to massive transcriptional reprogramming within 48 h of agroinfiltration. We observed that distinct host gene expression profiles were induced dependent on whether cell death occurs in a cell surface immune receptor-dependent or -independent manner. These gene expression profiles involved differential transcriptional networks mediated by WRKY, NAC and MYB transcription factors. In addition, differential expression of genes belonging to different classes of receptor-like proteins and receptor-like kinases was observed. These data suggest that different Z. tritici SSPs trigger differential transcriptional reprogramming in plant cells.
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Affiliation(s)
- Thomas Welch
- grid.6572.60000 0004 1936 7486Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK ,grid.6572.60000 0004 1936 7486School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
| | - Carlos Bayon
- grid.418374.d0000 0001 2227 9389Wheat Pathogenomics Team, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Jason J. Rudd
- grid.418374.d0000 0001 2227 9389Wheat Pathogenomics Team, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ UK
| | - Kostya Kanyuka
- grid.17595.3f0000 0004 0383 6532Cambridge Crop Research, National Institute of Agricultural Botany (NIAB), 93 Lawrence Weaver Road, Cambridge, CB3 0LE UK
| | - Graeme J. Kettles
- grid.6572.60000 0004 1936 7486Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK ,grid.6572.60000 0004 1936 7486School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT UK
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16
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Qian H, Song L, Wang L, Wang B, Liang W. The secreted FoAPY1 peptidase promotes Fusarium oxysporum invasion. Front Microbiol 2022; 13:1040302. [PMID: 36338032 PMCID: PMC9626516 DOI: 10.3389/fmicb.2022.1040302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/06/2022] [Indexed: 11/18/2022] Open
Abstract
The secretion of peptidases from several pathogens has been reported, but the biological function of these proteins in plant-pathogen interactions is poorly understood. Fusarium oxysporum, a soil-borne plant pathogenic fungus that causes Fusarium wilt in its host, can secrete proteins into host plant cells during the infection process to interfere with the host plant defense response and promote disease occurrence. In this study, we identified a peptidase, FoAPY1, that could be secreted from F. oxysporum depending on the N-terminal signal peptide of the protein. FoAPY1 belongs to the peptidase M28 family and exerts peptidase activity in vitro. Furthermore, the FoAYP1 gene knockout strain (∆FoAYP1) presented reduced virulence to tomato plants, but its mycelial growth and conidiation were unchanged. Moreover, FoAYP1 overexpression tomato seedlings exhibited enhanced susceptibility to F. oxysporum and Botrytis cinerea strains. These data demonstrated that FoAYP1 contributes to the virulence of F. oxysporum may through peptidase activity against host plant proteins.
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Affiliation(s)
- Hengwei Qian
- College of Life Sciences, Shandong Normal University, Jinan, China
| | - Limin Song
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Lulu Wang
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Baoshan Wang
- College of Life Sciences, Shandong Normal University, Jinan, China
| | - Wenxing Liang
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
- *Correspondence: Wenxing Liang,
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17
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Qian H, Wang L, Wang B, Liang W. The secreted ribonuclease T2 protein FoRnt2 contributes to Fusarium oxysporum virulence. MOLECULAR PLANT PATHOLOGY 2022; 23:1346-1360. [PMID: 35696123 PMCID: PMC9366063 DOI: 10.1111/mpp.13237] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/28/2022] [Accepted: 05/24/2022] [Indexed: 05/03/2023]
Abstract
Secreted RNase proteins have been reported from only a few pathogens, and relatively little is known about their biological functions. Fusarium oxysporum is a soilborne fungal pathogen that causes Fusarium wilt, one of the most important diseases on tomato. During the infection of F. oxysporum, some proteins are secreted that modulate host plant immunity and promote pathogen invasion. In this study, we identify an RNase, FoRnt2, from the F. oxysporum secretome that belongs to the ribonuclease T2 family. FoRnt2 possesses an N-terminal signal peptide and can be secreted from F. oxysporum. FoRnt2 exhibited ribonuclease activity and was able to degrade the host plant total RNA in vitro dependent on the active site residues H80 and H142. Deletion of the FoRnt2 gene reduced fungal virulence but had no obvious effect on mycelial growth and conidial production. The expression of FoRnt2 in tomato significantly enhanced plant susceptibility to pathogens. These data indicate that FoRnt2 is an important contributor to the virulence of F. oxysporum, possibly through the degradation of plant RNA.
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Affiliation(s)
- Hengwei Qian
- College of Life SciencesShandong Normal UniversityJinanChina
| | - Lulu Wang
- Key Lab of Integrated Crop Pest Management of Shandong ProvinceCollege of Plant Health and Medicine, Qingdao Agricultural UniversityQingdaoChina
| | - Baoshan Wang
- College of Life SciencesShandong Normal UniversityJinanChina
| | - Wenxing Liang
- Key Lab of Integrated Crop Pest Management of Shandong ProvinceCollege of Plant Health and Medicine, Qingdao Agricultural UniversityQingdaoChina
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18
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Kuang W, Zhang L, Ye L, Ma J, Shi X, Lin Y, Sun X, Cui R. Genome and Transcriptome Sequencing Analysis of Fusarium commune Provides Insights into the Pathogenic Mechanisms of the Lotus Rhizome Rot. Microbiol Spectr 2022; 10:e0017522. [PMID: 35867414 PMCID: PMC9431280 DOI: 10.1128/spectrum.00175-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 06/04/2022] [Indexed: 11/20/2022] Open
Abstract
Fusarium wilt, a vascular wilt caused by F. commune, has been a serious problem for the lotus. Although some F. commune isolate genomes have been sequenced, little is known about the genomic information of the strain that causes Fusarium wilt of aquatic plants. In this study, the genome of F. commune FCN23 isolated from lotuses in China was sequenced using Illumina and PacBio sequencing platforms. The FCN23 genome consisted of 53 scaffolds with a combined size of 46,211,149 bp. According to the reference genome, F. oxysporum f. sp. lycopersici 4287 isolated from tomato, it was finally assembled into 14 putative chromosomes, including 10 core and 4 lineage-specific chromosomes. The genome contains about 3.45% repeats and encodes 14,698 putative protein-coding genes. Among these, 1,038 and 296 proteins were potentially secreted proteins and candidate effector proteins, respectively. Comparative genomic analysis showed that the CAZyme-coding genes and secondary metabolite biosynthesis genes of FCN23 were similar to those of other Ascomycetes. Additionally, the transcriptome of FCN23 during infection of lotus was analyzed and 7,013 differentially expressed genes were identified. Eight putative effectors that were upregulated in the infection stage were cloned. Among them, F23a002499 exhibited strong hypersensitive response after transiently expressed in Nicotiana benthamiana leaves. Our results provide a valuable genetic basis for understanding the molecular mechanism of the interaction between F. commune and aquatic plants. IMPORTANCE Fusarium commune is an important soilborne pathogen with a wide range of hosts and can cause Fusarium wilt of land plants. However, there are few studies on Fusarium wilt of aquatic plants. Lotus rhizome rot mainly caused by F. commune is a devastating disease that causes extensive yield and quality losses in China. Here, we obtained high-quality genomic information of the FCN23 using Illumina NovaSeq and the third-generation sequencing technology PacBio Sequel II. Compared to the reference genome F. oxysporum f. sp. lycopersici strain 4287, it contains 11 core and 3 lineage-specific chromosomes. Many differentially expressed genes associated with pathogenicity were identified by RNA sequencing. The genome and transcriptome sequences of FCN23 will provide important genomic information and insights into the infection mechanisms of F. commune on aquatic plants.
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Affiliation(s)
- Weigang Kuang
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Lianhu Zhang
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Lifang Ye
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Jian Ma
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xugen Shi
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yachun Lin
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Xiaotang Sun
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Ruqiang Cui
- College of Agronomy, Jiangxi Agricultural University, Nanchang, Jiangxi, China
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19
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Yin C, Li J, Wang D, Zhang D, Song J, Kong Z, Wang B, Hu X, Klosterman SJ, Subbarao KV, Chen J, Dai X. A secreted ribonuclease effector from Verticillium dahliae localizes in the plant nucleus to modulate host immunity. MOLECULAR PLANT PATHOLOGY 2022; 23:1122-1140. [PMID: 35363930 PMCID: PMC9276946 DOI: 10.1111/mpp.13213] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/21/2022] [Accepted: 03/11/2022] [Indexed: 05/03/2023]
Abstract
The arms race between fungal pathogens and plant hosts involves recognition of fungal effectors to induce host immunity. Although various fungal effectors have been identified, the effector functions of ribonucleases are largely unknown. Herein, we identified a ribonuclease secreted by Verticillium dahliae (VdRTX1) that translocates into the plant nucleus to modulate immunity. The activity of VdRTX1 causes hypersensitive response (HR)-related cell death in Nicotiana benthamiana and cotton. VdRTX1 possesses a signal peptide but is unlikely to be an apoplastic effector because its nuclear localization in the plant is necessary for cell death induction. Knockout of VdRTX1 significantly enhanced V. dahliae virulence on tobacco while V. dahliae employs the known suppressor VdCBM1 to escape the immunity induced by VdRTX1. VdRTX1 homologs are widely distributed in fungi but transient expression of 24 homologs from other fungi did not yield cell death induction, suggesting that this function is specific to the VdRTX1 in V. dahliae. Expression of site-directed mutants of VdRTX1 in N. benthamiana leaves revealed conserved ligand-binding sites that are important for VdRTX1 function in inducing cell death. Thus, VdRTX1 functions as a unique HR-inducing effector in V. dahliae that contributes to the activation of plant immunity.
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Affiliation(s)
- Chun‐Mei Yin
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
- Institute of Food Science TechnologyChinese Academy of Agricultural SciencesBeijingChina
| | - Jun‐Jiao Li
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Dan Wang
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Dan‐Dan Zhang
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Jian Song
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Zhi‐Qiang Kong
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Bao‐Li Wang
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xiao‐Ping Hu
- State Key Laboratory of Crop Stress Biology for Arid AreasCollege of Plant ProtectionNorthwest A&F UniversityYanglingChina
| | - Steven J. Klosterman
- United States Department of AgricultureAgricultural Research ServiceSalinasCaliforniaUSA
| | - Krishna V. Subbarao
- Department of Plant PathologyUniversity of California, Davis, c/o U.S. Agricultural Research StationSalinasCaliforniaUSA
| | - Jie‐Yin Chen
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xiao‐Feng Dai
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
- Institute of Food Science TechnologyChinese Academy of Agricultural SciencesBeijingChina
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20
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He S, Huang Y, Sun Y, Liu B, Wang S, Xuan Y, Gao Z. The Secreted Ribonuclease SRE1 Contributes to Setosphaeria turcica Virulence and Activates Plant Immunity. Front Microbiol 2022; 13:941991. [PMID: 35875548 PMCID: PMC9304870 DOI: 10.3389/fmicb.2022.941991] [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: 05/12/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
During the plant infection process, pathogens can secrete several effectors. Some of the effectors are well-known for their roles in regulating plant immunity and promoting successful pathogen colonization. However, there are few studies on the ribonuclease (RNase) effectors secreted by fungi. In the present study, we discovered a secretable RNase (SRE1) in the secretome of Setosphaeria turcica that was significantly upregulated during the early stages of S. turcica infection in maize. Knockdown of SRE1 significantly reduced the virulence of S. turcica. SRE1 can induce cell death in maize and Nicotiana benthamiana. However, unlike the conventional hypersensitive response (HR) caused by other effectors, SRE1 is not dependent on its signal peptide (SP) or plant receptor kinases (such as BAK1 and SOBIR1). SRE1-induced cell death depends upon its enzymatic activity and the N-terminal β-hairpin structure. SRE1 relies on its N-terminal β-hairpin structure to enter cells, and then degrades plant's RNA through its catalytic activity causing cytotoxic effects. Additionally, SRE1 enhances N. benthamiana's resistance to pathogenic fungi and oomycetes. In summary, SRE1 promotes the virulence of S. turcica, inducing plant cell death and activating plant immune responses.
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Affiliation(s)
- Shidao He
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Yufei Huang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Yanqiu Sun
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Bo Liu
- College of Life Sciences, Yan'an University, Yan'an, China
| | - Suna Wang
- College of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, China
| | - Yuanhu Xuan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Zenggui Gao
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- *Correspondence: Zenggui Gao
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21
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Action Mechanisms of Effectors in Plant-Pathogen Interaction. Int J Mol Sci 2022; 23:ijms23126758. [PMID: 35743201 PMCID: PMC9224169 DOI: 10.3390/ijms23126758] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [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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22
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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; 46:6590816. [PMID: 35604874 PMCID: PMC9438471 DOI: 10.1093/femsre/fuac022] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [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 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, Cologne, Germany.,Theoretical Biology & Bioinformatics Group, Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - Hanna Rovenich
- Institute for Plant Sciences, University of Cologne, Cologne, Germany
| | - Bart P H J Thomma
- Institute for Plant Sciences, University of Cologne, Cologne, Germany.,Cluster of Excellence on Plant Sciences, Institute for Plant Sciences, University of Cologne, CologneGermany
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23
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Li J, Wang C, Liang W, Liu S. Rhizosphere Microbiome: The Emerging Barrier in Plant-Pathogen Interactions. Front Microbiol 2021; 12:772420. [PMID: 34777326 PMCID: PMC8586421 DOI: 10.3389/fmicb.2021.772420] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/13/2021] [Indexed: 01/07/2023] Open
Abstract
In the ecosystem, microbiome widely exists in soil, animals, and plants. With the rapid development of computational biology, sequencing technology and omics analysis, the important role of soil beneficial microbial community is being revealed. In this review, we mainly summarized the roles of rhizosphere microbiome, revealing its complex and pervasive nature contributing to the largely invisible interaction with plants. The manipulated beneficial microorganisms function as an indirect layer of the plant immune system by acting as a barrier to pathogen invasion or inducing plant systemic resistance. Specifically, plant could change and recruit beneficial microbial communities through root-type-specific metabolic properties, and positively shape their rhizosphere microorganisms in response to pathogen invasion. Meanwhile, plants and beneficial microbes exhibit the abilities to avoid excessive immune responses for their reciprocal symbiosis. Substantial lines of evidence show pathogens might utilize secreting proteins/effectors to overcome the emerging peripheral barrier for their advantage in turn. Overall, beneficial microbial communities in rhizosphere are involved in plant-pathogen interactions, and its power and potential are being explored and explained with the aim to effectively increase plant growth and productivity.
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Affiliation(s)
- Jingtao Li
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Chenyang Wang
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Wenxing Liang
- Key Lab of Integrated Crop Pest Management of Shandong Province, College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Sihui Liu
- College of Science and Information, Qingdao Agricultural University, Qingdao, China
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24
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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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25
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Jones DAB, Moolhuijzen PM, Hane JK. Remote homology clustering identifies lowly conserved families of effector proteins in plant-pathogenic fungi. Microb Genom 2021; 7. [PMID: 34468307 PMCID: PMC8715435 DOI: 10.1099/mgen.0.000637] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Plant diseases caused by fungal pathogens are typically initiated by molecular interactions between 'effector' molecules released by a pathogen and receptor molecules on or within the plant host cell. In many cases these effector-receptor interactions directly determine host resistance or susceptibility. The search for fungal effector proteins is a developing area in fungal-plant pathology, with more than 165 distinct confirmed fungal effector proteins in the public domain. For a small number of these, novel effectors can be rapidly discovered across multiple fungal species through the identification of known effector homologues. However, many have no detectable homology by standard sequence-based search methods. This study employs a novel comparison method (RemEff) that is capable of identifying protein families with greater sensitivity than traditional homology-inference methods, leveraging a growing pool of confirmed fungal effector data to enable the prediction of novel fungal effector candidates by protein family association. Resources relating to the RemEff method and data used in this study are available from https://figshare.com/projects/Effector_protein_remote_homology/87965.
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Affiliation(s)
- Darcy A B Jones
- Centre for Crop & Disease Management, School of Molecular & Life Sciences, Curtin University, Perth, Australia
| | - Paula M Moolhuijzen
- Centre for Crop & Disease Management, School of Molecular & Life Sciences, Curtin University, Perth, Australia
| | - James K Hane
- Centre for Crop & Disease Management, School of Molecular & Life Sciences, Curtin University, Perth, Australia.,Curtin Institute for Computation, Curtin University, Perth, Australia
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26
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Outram MA, Sung YC, Yu D, Dagvadorj B, Rima SA, Jones DA, Ericsson DJ, Sperschneider J, Solomon PS, Kobe B, Williams SJ. The crystal structure of SnTox3 from the necrotrophic fungus Parastagonospora nodorum reveals a unique effector fold and provides insight into Snn3 recognition and pro-domain protease processing of fungal effectors. THE NEW PHYTOLOGIST 2021; 231:2282-2296. [PMID: 34053091 DOI: 10.1111/nph.17516] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 05/20/2021] [Indexed: 05/22/2023]
Abstract
Plant pathogens cause disease through secreted effector proteins, which act to promote infection. Typically, the sequences of effectors provide little functional information and further targeted experimentation is required. Here, we utilized a structure/function approach to study SnTox3, an effector from the necrotrophic fungal pathogen Parastagonospora nodorum, which causes cell death in wheat-lines carrying the sensitivity gene Snn3. We developed a workflow for the production of SnTox3 in a heterologous host that enabled crystal structure determination and functional studies. We show this approach can be successfully applied to study effectors from other pathogenic fungi. The β-barrel fold of SnTox3 is a novel fold among fungal effectors. Structure-guided mutagenesis enabled the identification of residues required for Snn3 recognition. SnTox3 is a pre-pro-protein, and the pro-domain of SnTox3 can be cleaved in vitro by the protease Kex2. Complementing this, an in silico study uncovered the prevalence of a conserved motif (LxxR) in an expanded set of putative pro-domain-containing fungal effectors, some of which can be cleaved by Kex2 in vitro. Our in vitro and in silico study suggests that Kex2-processed pro-domain (designated here as K2PP) effectors are common in fungi and this may have broad implications for the approaches used to study their functions.
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Affiliation(s)
- Megan A Outram
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yi-Chang Sung
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Daniel Yu
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bayantes Dagvadorj
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Sharmin A Rima
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - David A Jones
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Daniel J Ericsson
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Australian Synchrotron, Macromolecular Crystallography, Clayton, VIC, 3168, Australia
| | - Jana Sperschneider
- Biological Data Science Institute, The Australian National University, Canberra, ACT, 2601, Australia
| | - Peter S Solomon
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Simon J Williams
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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27
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Outram MA, Sung YC, Yu D, Dagvadorj B, Rima SA, Jones DA, Ericsson DJ, Sperschneider J, Solomon PS, Kobe B, Williams SJ. The crystal structure of SnTox3 from the necrotrophic fungus Parastagonospora nodorum reveals a unique effector fold and provides insight into Snn3 recognition and pro-domain protease processing of fungal effectors. THE NEW PHYTOLOGIST 2021; 231:2282-2296. [PMID: 34053091 DOI: 10.1101/2020.05.27.120113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 05/20/2021] [Indexed: 05/25/2023]
Abstract
Plant pathogens cause disease through secreted effector proteins, which act to promote infection. Typically, the sequences of effectors provide little functional information and further targeted experimentation is required. Here, we utilized a structure/function approach to study SnTox3, an effector from the necrotrophic fungal pathogen Parastagonospora nodorum, which causes cell death in wheat-lines carrying the sensitivity gene Snn3. We developed a workflow for the production of SnTox3 in a heterologous host that enabled crystal structure determination and functional studies. We show this approach can be successfully applied to study effectors from other pathogenic fungi. The β-barrel fold of SnTox3 is a novel fold among fungal effectors. Structure-guided mutagenesis enabled the identification of residues required for Snn3 recognition. SnTox3 is a pre-pro-protein, and the pro-domain of SnTox3 can be cleaved in vitro by the protease Kex2. Complementing this, an in silico study uncovered the prevalence of a conserved motif (LxxR) in an expanded set of putative pro-domain-containing fungal effectors, some of which can be cleaved by Kex2 in vitro. Our in vitro and in silico study suggests that Kex2-processed pro-domain (designated here as K2PP) effectors are common in fungi and this may have broad implications for the approaches used to study their functions.
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Affiliation(s)
- Megan A Outram
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yi-Chang Sung
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Daniel Yu
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bayantes Dagvadorj
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Sharmin A Rima
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - David A Jones
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Daniel J Ericsson
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
- Australian Synchrotron, Macromolecular Crystallography, Clayton, VIC, 3168, Australia
| | - Jana Sperschneider
- Biological Data Science Institute, The Australian National University, Canberra, ACT, 2601, Australia
| | - Peter S Solomon
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Simon J Williams
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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28
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Hao Z, Li Y, Jiang Y, Xu J, Li J, Luo L. Genome Sequence Analysis of the Fungal Pathogen Fusarium graminearum Using Oxford Nanopore Technology. J Fungi (Basel) 2021; 7:jof7090699. [PMID: 34575738 PMCID: PMC8465144 DOI: 10.3390/jof7090699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/20/2022] Open
Abstract
Fusarium graminearum is a plant pathogen of global importance which causes not only significant yield loss but also crop spoilage due to mycotoxins that render grain unsafe for human or livestock consumption. Although the full genome of several F. graminearum isolates from different parts of the world have been sequenced, there are no similar studies of isolates originating from China. The current study sought to address this by sequencing the F. graminearum isolate FG-12, which was isolated from the roots of maize seedlings exhibiting typical symptoms of blight growing in the Gansu province, China, using Oxford Nanopore Technology (ONT). The FG-12 isolate was found to have a 35.9 Mb genome comprised of five scaffolds corresponding to the four chromosomes and mitochondrial DNA of the F. graminearum type strain, PH-1. The genome was found to contain an approximately 2.23% repetitive sequence and encode 12,470 predicted genes. Additional bioinformatic analysis identified 437 genes that were predicted to be secreted effectors, one of which was confirmed to trigger a hypersensitive responses (HR) in the leaves of Nicotiana benthamiana during transient expression experiments utilizing agro-infiltration. The F. graminearum FG-12 genome sequence and annotation data produced in the current study provide an extremely useful resource for both intra- and inter-species comparative analyses as well as for gene functional studies, and could greatly advance our understanding of this important plant pathogen.
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29
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Chang HX, Noel ZA, Chilvers MI. A β-lactamase gene of Fusarium oxysporum alters the rhizosphere microbiota of soybean. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:1588-1604. [PMID: 33788336 DOI: 10.1111/tpj.15257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
The rhizosphere is a multitrophic environment, and for soilborne pathogens such as Fusarium oxysporum, microbial competition in the rhizosphere is inevitable before reaching and infecting roots. This study established a tritrophic interaction among the plant growth-promoting rhizobacterium Burkholderia ambifaria, F. oxysporum and Glycine max (soybean) to study the effects of F. oxysporum genes on shaping the soybean microbiota. Although B. ambifaria inhibited mycelial growth and increased bacterial propagation in the presence of F. oxysporum, F. oxysporum still managed to infect soybean in the presence of B. ambifaria. RNA-Seq identified a putative F. oxysporum secretory β-lactamase-coding gene, FOXG_18438 (abbreviated as Fo18438), that is upregulated during soybean infection in the presence of B. ambifaria. The ∆Fo18438 mutants displayed reduced mycelial growth towards B. ambifaria, and the complementation of full Fo18438 and the Fo18438 β-lactamase domain restored mycelial growth. Using the F. oxysporum wild type, ∆Fo18438 mutants and complemented strains with full Fo18438, Fo18438 β-lactamase domain or Fo18438 RTA1-like domain for soil inoculation, 16S rRNA amplicon sequencing revealed that the abundance of a Burkholderia operational taxonomic unit (OTU) was increased in the rhizosphere microbiota infested by the strains with Fo18438 β-lactamase domain. Non-metric multidimensional scaling and PICRUSt2 functional analysis revealed differential abundance for the bacterial β-lactam-related functions when contrasting the genotypes of F. oxysporum. These results indicated that the Fo18438 β-lactamase domain provides F. oxysporum with the advantage of growing into the soybean rhizosphere, where β-lactam antibiosis is involved in microbial competition. Accordingly, this study highlights the capability of an F. oxysporum gene for altering the soybean rhizosphere and taproot microbiota.
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Affiliation(s)
- Hao-Xun Chang
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617, Taiwan
| | - Zachary A Noel
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
| | - Martin I Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
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30
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Sacristán S, Goss EM, Eves-van den Akker S. How Do Pathogens Evolve Novel Virulence Activities? MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:576-586. [PMID: 33522842 DOI: 10.1094/mpmi-09-20-0258-ia] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This article is part of the Top 10 Unanswered Questions in MPMI invited review series.We consider the state of knowledge on pathogen evolution of novel virulence activities, broadly defined as anything that increases pathogen fitness with the consequence of causing disease in either the qualitative or quantitative senses, including adaptation of pathogens to host immunity and physiology, host species, genotypes, or tissues, or the environment. The evolution of novel virulence activities as an adaptive trait is based on the selection exerted by hosts on variants that have been generated de novo or arrived from elsewhere. In addition, the biotic and abiotic environment a pathogen experiences beyond the host may influence pathogen virulence activities. We consider host-pathogen evolution, host range expansion, and external factors that can mediate pathogen evolution. We then discuss the mechanisms by which pathogens generate and recombine the genetic variation that leads to novel virulence activities, including DNA point mutation, transposable element activity, gene duplication and neofunctionalization, and genetic exchange. In summary, if there is an (epi)genetic mechanism that can create variation in the genome, it will be used by pathogens to evolve virulence factors. Our knowledge of virulence evolution has been biased by pathogen evolution in response to major gene resistance, leaving other virulence activities underexplored. Understanding the key driving forces that give rise to novel virulence activities and the integration of evolutionary concepts and methods with mechanistic research on plant-microbe interactions can help inform crop protection.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Soledad Sacristán
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo-UPM, 28223-Pozuelo de Alarcón (Madrid), Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040-Madrid, Spain
| | - Erica M Goss
- Department of Plant Pathology and Emerging Pathogens Institute, University of Florida, Gainesville, Florida, U.S.A
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31
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Ebert MK, Rangel LI, Spanner RE, Taliadoros D, Wang X, Friesen TL, de Jonge R, Neubauer JD, Secor GA, Thomma BPHJ, Stukenbrock EH, Bolton MD. Identification and characterization of Cercospora beticola necrosis-inducing effector CbNip1. MOLECULAR PLANT PATHOLOGY 2021; 22:301-316. [PMID: 33369055 PMCID: PMC7865086 DOI: 10.1111/mpp.13026] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 05/30/2023]
Abstract
Cercospora beticola is a hemibiotrophic fungus that causes cercospora leaf spot disease of sugar beet (Beta vulgaris). After an initial symptomless biotrophic phase of colonization, necrotic lesions appear on host leaves as the fungus switches to a necrotrophic lifestyle. The phytotoxic secondary metabolite cercosporin has been shown to facilitate fungal virulence for several Cercospora spp. However, because cercosporin production and subsequent cercosporin-initiated formation of reactive oxygen species is light-dependent, cell death evocation by this toxin is only fully ensured during a period of light. Here, we report the discovery of the effector protein CbNip1 secreted by C. beticola that causes enhanced necrosis in the absence of light and, therefore, may complement light-dependent necrosis formation by cercosporin. Infiltration of CbNip1 protein into sugar beet leaves revealed that darkness is essential for full CbNip1-triggered necrosis, as light exposure delayed CbNip1-triggered host cell death. Gene expression analysis during host infection shows that CbNip1 expression is correlated with symptom development in planta. Targeted gene replacement of CbNip1 leads to a significant reduction in virulence, indicating the importance of CbNip1 during colonization. Analysis of 89 C. beticola genomes revealed that CbNip1 resides in a region that recently underwent a selective sweep, suggesting selection pressure exists to maintain a beneficial variant of the gene. Taken together, CbNip1 is a crucial effector during the C. beticola-sugar beet disease process.
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Affiliation(s)
- Malaika K. Ebert
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
- Present address:
Department of Plant BiologyMichigan State UniversityEast LansingMichiganUSA
| | - Lorena I. Rangel
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
| | - Rebecca E. Spanner
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Demetris Taliadoros
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Christian‐Albrechts University of KielKielGermany
| | - Xiaoyun Wang
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Present address:
Institute of BiotechnologyCornell UniversityIthacaNew YorkUSA
| | - Timothy L. Friesen
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Ronnie de Jonge
- Plant‐Microbe InteractionsDepartment of BiologyUtrecht UniversityUtrechtNetherlands
- Department of Plant Systems BiologyVIBGhentBelgium
- Department of Plant Biotechnology and BioinformaticsGhent UniversityGhentBelgium
| | - Jonathan D. Neubauer
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
| | - Gary A. Secor
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
| | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen UniversityWageningenNetherlands
- University of Cologne, Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS)CologneGermany
| | - Eva H. Stukenbrock
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Christian‐Albrechts University of KielKielGermany
| | - Melvin D. Bolton
- Edward T. Schafer Agricultural Research CenterUSDA Agricultural Research ServiceFargoNorth DakotaUSA
- Department of Plant PathologyNorth Dakota State UniversityFargoNorth DakotaUSA
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Karki SJ, Reilly A, Zhou B, Mascarello M, Burke J, Doohan F, Douchkov D, Schweizer P, Feechan A. A small secreted protein from Zymoseptoria tritici interacts with a wheat E3 ubiquitin ligase to promote disease. JOURNAL OF EXPERIMENTAL BOTANY 2021. [PMID: 33095257 DOI: 10.5061/dryad.9w0vt4bcx] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Septoria tritici blotch (STB), caused by the ascomycete fungus Zymoseptoria tritici, is a major threat to wheat production worldwide. The Z. tritici genome encodes many small secreted proteins (ZtSSPs) that are likely to play a key role in the successful colonization of host tissues. However, few of these ZtSSPs have been functionally characterized for their role during infection. In this study, we identified and characterized a small, conserved cysteine-rich secreted effector from Z. tritici which has homologues in other plant pathogens in the Dothideomycetes. ZtSSP2 was expressed throughout Z. tritici infection in wheat, with the highest levels observed early during infection. A yeast two-hybrid assay revealed an interaction between ZtSSP2 and wheat E3 ubiquitin ligase (TaE3UBQ) in yeast, and this was further confirmed in planta using bimolecular fluorescence complementation and co-immunoprecipitation. Down-regulation of this wheat E3 ligase using virus-induced gene silencing increased the susceptibility of wheat to STB. Together, these results suggest that TaE3UBQ is likely to play a role in plant immunity to defend against Z. tritici.
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Affiliation(s)
- Sujit Jung Karki
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aisling Reilly
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Binbin Zhou
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Maurizio Mascarello
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Ecology, Evolution and Biodiversity Conservation, Charles Deberiotstraat 8 32, 3000 Leuven, Belgium
| | - James Burke
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Fiona Doohan
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dimitar Douchkov
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Patrick Schweizer
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Angela Feechan
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
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33
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Karki SJ, Reilly A, Zhou B, Mascarello M, Burke J, Doohan F, Douchkov D, Schweizer P, Feechan A. A small secreted protein from Zymoseptoria tritici interacts with a wheat E3 ubiquitin ligase to promote disease. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:733-746. [PMID: 33095257 PMCID: PMC7853600 DOI: 10.1093/jxb/eraa489] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 10/15/2020] [Indexed: 05/05/2023]
Abstract
Septoria tritici blotch (STB), caused by the ascomycete fungus Zymoseptoria tritici, is a major threat to wheat production worldwide. The Z. tritici genome encodes many small secreted proteins (ZtSSPs) that are likely to play a key role in the successful colonization of host tissues. However, few of these ZtSSPs have been functionally characterized for their role during infection. In this study, we identified and characterized a small, conserved cysteine-rich secreted effector from Z. tritici which has homologues in other plant pathogens in the Dothideomycetes. ZtSSP2 was expressed throughout Z. tritici infection in wheat, with the highest levels observed early during infection. A yeast two-hybrid assay revealed an interaction between ZtSSP2 and wheat E3 ubiquitin ligase (TaE3UBQ) in yeast, and this was further confirmed in planta using bimolecular fluorescence complementation and co-immunoprecipitation. Down-regulation of this wheat E3 ligase using virus-induced gene silencing increased the susceptibility of wheat to STB. Together, these results suggest that TaE3UBQ is likely to play a role in plant immunity to defend against Z. tritici.
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Affiliation(s)
- Sujit Jung Karki
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aisling Reilly
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Binbin Zhou
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Maurizio Mascarello
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Ecology, Evolution and Biodiversity Conservation, Charles Deberiotstraat 8 32, 3000 Leuven, Belgium
| | - James Burke
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Fiona Doohan
- School of Biology and Environmental Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Dimitar Douchkov
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Patrick Schweizer
- Institute of Plant Genetics and Crop Plant Research (IPK), Cytogenetics, Gatersleben, Germany
| | - Angela Feechan
- School of Agriculture & Food Science and UCD Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Correspondence:
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Yang B, Wang Y, Tian M, Dai K, Zheng W, Liu Z, Yang S, Liu X, Shi D, Zhang H, Wang Y, Ye W, Wang Y. Fg12 ribonuclease secretion contributes to Fusarium graminearum virulence and induces plant cell death. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:365-377. [PMID: 32725938 DOI: 10.1111/jipb.12997] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
Filamentous fungal pathogens secrete effectors that modulate host immunity and facilitate infection. Fusarium graminearum is an important plant pathogen responsible for various devastating diseases. However, little is known about the function of effector proteins secreted by F. graminearum. Herein, we identified several effector candidates in the F. graminearum secretome. Among them, the secreted ribonuclease Fg12 was highly upregulated during the early stages of F. graminearum infection in soybean; its deletion compromised the virulence of F. graminearum. Transient expression of Fg12 in Nicotiana benthamiana induced cell death in a light-dependent manner. Fg12 possessed ribonuclease (RNase) activity, degrading total RNA. The enzymatic activity of Fg12 was required for its cell death-promoting effects. Importantly, the ability of Fg12 to induce cell death was independent of BAK1/SOBIR1, and treatment of soybean with recombinant Fg12 protein induced resistance to various pathogens, including F. graminearum and Phytophthora sojae. Overall, our results provide evidence that RNase effectors not only contribute to pathogen virulence but also induce plant cell death.
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Affiliation(s)
- Bo Yang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuyin Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mengjun Tian
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Kaixin Dai
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenyue Zheng
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zehan Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Sen Yang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xinyu Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dongya Shi
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haifeng Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yan Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
- The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
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35
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Saur IML, Hückelhoven R. Recognition and defence of plant-infecting fungal pathogens. JOURNAL OF PLANT PHYSIOLOGY 2021; 256:153324. [PMID: 33249386 DOI: 10.1016/j.jplph.2020.153324] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/04/2020] [Accepted: 11/04/2020] [Indexed: 06/12/2023]
Abstract
Attempted infections of plants with fungi result in diverse outcomes ranging from symptom-less resistance to severe disease and even death of infected plants. The deleterious effect on crop yield have led to intense focus on the cellular and molecular mechanisms that explain the difference between resistance and susceptibility. This research has uncovered plant resistance or susceptibility genes that explain either dominant or recessive inheritance of plant resistance with many of them coding for receptors that recognize pathogen invasion. Approaches based on cell biology and phytochemistry have contributed to identifying factors that halt an invading fungal pathogen from further invasion into or between plant cells. Plant chemical defence compounds, antifungal proteins and structural reinforcement of cell walls appear to slow down fungal growth or even prevent fungal penetration in resistant plants. Additionally, the hypersensitive response, in which a few cells undergo a strong local immune reaction, including programmed cell death at the site of infection, stops in particular biotrophic fungi from spreading into surrounding tissue. In this review, we give a general overview of plant recognition and defence of fungal parasites tracing back to the early 20th century with a special focus on Triticeae and on the progress that was made in the last 30 years.
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Affiliation(s)
- Isabel M L Saur
- Max Planck Institute for Plant Breeding Research, Department of Plant-Microbe Interactions, Carl-von-Linné-Weg 10, 50829 Cologne, Germany.
| | - Ralph Hückelhoven
- Phytopathology, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Ramann-Straße 2, 85354 Freising, Germany.
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36
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Chromatin Dynamics Contribute to the Spatiotemporal Expression Pattern of Virulence Genes in a Fungal Plant Pathogen. mBio 2020; 11:mBio.02343-20. [PMID: 33024042 PMCID: PMC7542367 DOI: 10.1128/mbio.02343-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fungal plant pathogens possess a large repertoire of genes encoding putative effectors, which are crucial for infection. Many of these genes are expressed at low levels in the absence of the host but are strongly induced at specific stages of the infection. The mechanisms underlying this transcriptional reprogramming remain largely unknown. We investigated the role of the genomic environment and associated chromatin modifications of effector genes in controlling their expression pattern in the fungal wheat pathogen Zymoseptoria tritici. Depending on their genomic location, effector genes are epigenetically repressed in the absence of the host and during the initial stages of infection. Derepression of effector genes occurs mainly during and after penetration of plant leaves and is associated with changes in histone modifications. Our work demonstrates the role of chromatin in shaping the expression of virulence components and, thereby, the interaction between fungal pathogens and their plant hosts. Dynamic changes in transcription profiles are key for the success of pathogens in colonizing their hosts. In many pathogens, genes associated with virulence, such as effector genes, are located in regions of the genome that are rich in transposable elements and heterochromatin. The contribution of chromatin modifications to gene expression in pathogens remains largely unknown. Using a combination of a reporter gene-based approach and chromatin immunoprecipitation, we show that the heterochromatic environment of effector genes in the fungal plant pathogen Zymoseptoria tritici is a key regulator of their specific spatiotemporal expression patterns. Enrichment in trimethylated lysine 27 of histone H3 dictates the repression of effector genes in the absence of the host. Chromatin decondensation during host colonization, featuring a reduction in this repressive modification, indicates a major role for epigenetics in effector gene induction. Our results illustrate that chromatin modifications triggered during host colonization determine the specific expression profile of effector genes at the cellular level and, hence, provide new insights into the regulation of virulence in fungal plant pathogens.
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37
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Mukherjee D, Gupta S, Ghosh A, Ghosh A. Ustilago maydis secreted T2 ribonucleases, Nuc1 and Nuc2 scavenge extracellular RNA. Cell Microbiol 2020; 22:e13256. [PMID: 32844528 DOI: 10.1111/cmi.13256] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/18/2020] [Indexed: 12/22/2022]
Abstract
Ustilago maydis genome codes for many secreted ribonucleases. The contribution of two among these belonging to the T2 family (Nuc1 and Nuc2) in the pathogen virulence, has been assessed in this study. The nuc1 and nuc2 deletion mutants showed not only reduced pathogenicity compared to the SG200 WT strain but also exhibited significant delay in the completion of the pathogenic lifecycle. Both the proteins were also tested for their nucleolytic activities towards RNA substrates from maize and yeast. This also yielded valuable insights into the ability of the ribonucleases to utilise extracellular RNA as a nutrient source. Our study therefore established a role of two T2 type secreted ribonucleases of a phytopathogen in the acquisition of nutrient for the first time. This study also provides evidence that maize apoplast contains RNA, which can be utilised as a substrate by both Nuc1 and Nuc2.
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Affiliation(s)
- Dibya Mukherjee
- Division of Plant Biology, Bose Institute Centenary Campus, Kolkata, India
| | - Sayandeep Gupta
- Department of Biochemistry, Bose Institute Centenary Campus, Kolkata, India
| | - Abhrajyoti Ghosh
- Department of Biochemistry, Bose Institute Centenary Campus, Kolkata, India
| | - Anupama Ghosh
- Division of Plant Biology, Bose Institute Centenary Campus, Kolkata, India
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38
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Seybold H, Demetrowitsch TJ, Hassani MA, Szymczak S, Reim E, Haueisen J, Lübbers L, Rühlemann M, Franke A, Schwarz K, Stukenbrock EH. A fungal pathogen induces systemic susceptibility and systemic shifts in wheat metabolome and microbiome composition. Nat Commun 2020; 11:1910. [PMID: 32313046 PMCID: PMC7171108 DOI: 10.1038/s41467-020-15633-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 03/13/2020] [Indexed: 12/14/2022] Open
Abstract
Yield losses caused by fungal pathogens represent a major threat to global food production. One of the most devastating fungal wheat pathogens is Zymoseptoria tritici. Despite the importance of this fungus, the underlying mechanisms of plant–pathogen interactions are poorly understood. Here we present a conceptual framework based on coinfection assays, comparative metabolomics, and microbiome profiling to study the interaction of Z. tritici in susceptible and resistant wheat. We demonstrate that Z. tritici suppresses the production of immune-related metabolites in a susceptible cultivar. Remarkably, this fungus-induced immune suppression spreads within the leaf and even to other leaves, a phenomenon that we term “systemic induced susceptibility”. Using a comparative metabolomics approach, we identify defense-related biosynthetic pathways that are suppressed and induced in susceptible and resistant cultivars, respectively. We show that these fungus-induced changes correlate with changes in the wheat leaf microbiome. Our findings suggest that immune suppression by this hemibiotrophic pathogen impacts specialized plant metabolism, alters its associated microbial communities, and renders wheat vulnerable to further infections. The fungal plant pathogen Zymoseptoria tritici is a major threat to wheat yield. Here Seybold et al. show that Z. tritici can suppress immune responses not only in infected tissue but also on other leaves, a phenomenon termed “systemic induced susceptibility” that is correlated with systemic changes in metabolite accumulation.
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Affiliation(s)
- Heike Seybold
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.,Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, 9190401, Israel
| | - Tobias J Demetrowitsch
- Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - M Amine Hassani
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Silke Szymczak
- Institute of Medical Informatics and Statistics, Kiel University, University Hospital Schleswig Holstein Campus Kiel, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Ekaterina Reim
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - Janine Haueisen
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany
| | - Luisa Lübbers
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany
| | - Malte Rühlemann
- Institute of Clinical Molecular Biology, Kiel University, Am Botanischen Garten 11, 24118, Kiel, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Kiel University, Am Botanischen Garten 11, 24118, Kiel, Germany
| | - Karin Schwarz
- Institute of Human Nutrition and Food Science, Kiel University, Heinrich-Hecht-Platz 10, 24118, Kiel, Germany
| | - Eva H Stukenbrock
- Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118, Kiel, Germany. .,Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, 24306, Plön, Germany.
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39
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Wen Z, Zeng Z, Ren F, Asiegbu FO. The Conifer Root and Stem Rot Pathogen ( Heterobasidion parviporum): Effectome Analysis and Roles in Interspecific Fungal Interactions. Microorganisms 2019; 7:microorganisms7120658. [PMID: 31817407 PMCID: PMC6955712 DOI: 10.3390/microorganisms7120658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 11/16/2022] Open
Abstract
Heterobasidion parviporum Niemelä & Korhonen is an economically important basidiomycete, causing root and stem rot disease of Norway spruce (Picea abies (L.) Karst) in Northern Europe. The H. parviporum genome encodes numerous small secreted proteins, which might be of importance for interacting with mycorrhiza symbionts, endophytes, and other saprotrophs. We hypothesized that small secreted proteins from H. parviporum (HpSSPs) are involved in interspecific fungal interaction. To identify HpSSP-coding genes potentially involved, we screened the H. parviporum effectome and compared their transcriptomic profiles during fungal development and in planta tree infection. We further conducted phylogenetic analysis, and identified a subset of hypothetical proteins with nonpredicted domain or unknown function as HpSSPs candidates for further characterization. The HpSSPs candidates were selected based on high-quality sequence, cysteine residue frequency, protein size, and in planta expression. We subsequently explored their roles during in vitro interaction in paired cultures of H. parviporum with ectomycorrhizal Cortinarius gentilis, endophytic Phialocephala sphaeroides, saprotrophs (Mycena sp., Phlebiopsis gigantea, and Phanerochaete chrysosporium), respectively. The transcriptomic profile revealed that a large proportion of effector candidates was either barely expressed or highly expressed under all growth conditions. In vitro dual-culture test showed that P. sphaeroides and C. gentilis were overgrown by H. parviporum. The barrage zone formation or no physical contact observed in paired cultures with the saprotrophs suggest they had either combative interaction or antibiosis effect with H. parviporum. Several HpSSPs individuals were up- or downregulated during the nonself interactions. The results of HpSSPs gene expression patterns provide additional insights into the diverse roles of SSPs in tree infection and interspecific fungal interactions.
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Affiliation(s)
- Zilan Wen
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, University of Helsinki, 00014 Helsinki, Finland; (Z.W.); (Z.Z.); (F.R.)
| | - Zhen Zeng
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, University of Helsinki, 00014 Helsinki, Finland; (Z.W.); (Z.Z.); (F.R.)
| | - Fei Ren
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, University of Helsinki, 00014 Helsinki, Finland; (Z.W.); (Z.Z.); (F.R.)
- Experimental Center of Forestry in North China, Chinese Academy of Forestry, No. 1 Shuiza Road, Beijing 102300, China
| | - Fred O. Asiegbu
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, University of Helsinki, 00014 Helsinki, Finland; (Z.W.); (Z.Z.); (F.R.)
- Correspondence: ; Tel.: +358-294158109
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40
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Heterologous Production and Functional Characterization of Ageritin, a Novel Type of Ribotoxin Highly Expressed during Fruiting of the Edible Mushroom Agrocybe aegerita. Appl Environ Microbiol 2019; 85:AEM.01549-19. [PMID: 31444206 DOI: 10.1128/aem.01549-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 08/21/2019] [Indexed: 12/11/2022] Open
Abstract
Fungi produce various defense proteins against antagonists, including ribotoxins. These toxins cleave a single phosphodiester bond within the universally conserved sarcin-ricin loop of ribosomes and inhibit protein biosynthesis. Here, we report on the structure and function of ageritin, a previously reported ribotoxin from the edible mushroom Agrocybe aegerita The amino acid sequence of ageritin was derived from cDNA isolated from the dikaryon A. aegerita AAE-3 and lacks, according to in silico prediction, a signal peptide for classical secretion, predicting a cytoplasmic localization of the protein. The calculated molecular weight of the protein is slightly higher than the one reported for native ageritin. The A. aegerita ageritin-encoding gene, AaeAGT1, is highly induced during fruiting, and toxicity assays with AaeAGT1 heterologously expressed in Escherichia coli showed a strong toxicity against Aedes aegypti larvae yet not against nematodes. The activity of recombinant A. aegerita ageritin toward rabbit ribosomes was confirmed in vitro Mutagenesis studies revealed a correlation between in vivo and in vitro activities, indicating that entomotoxicity is mediated by ribonucleolytic cleavage. The strong larvicidal activity of ageritin makes this protein a promising candidate for novel biopesticide development.IMPORTANCE Our results suggest a pronounced organismal specificity of a protein toxin with a very conserved intracellular molecular target. The molecular details of the toxin-target interaction will provide important insight into the mechanism of action of protein toxins and the ribosome. This insight might be exploited to develop novel bioinsecticides.
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Sarkar D, Rovenich H, Jeena G, Nizam S, Tissier A, Balcke GU, Mahdi LK, Bonkowski M, Langen G, Zuccaro A. The inconspicuous gatekeeper: endophytic Serendipita vermifera acts as extended plant protection barrier in the rhizosphere. THE NEW PHYTOLOGIST 2019; 224:886-901. [PMID: 31074884 DOI: 10.1111/nph.15904] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/26/2019] [Indexed: 05/21/2023]
Abstract
In nature, beneficial and pathogenic fungi often simultaneously colonise plants. Despite substantial efforts to understand the composition of natural plant-microbe communities, the mechanisms driving such multipartite interactions remain largely unknown. Here we address how the interaction between the beneficial root endophyte Serendipita vermifera and the pathogen Bipolaris sorokiniana affects fungal behaviour and determines barley host responses using a gnotobiotic soil-based split-root system. Fungal confrontation in soil resulted in induction of B. sorokiniana genes involved in secondary metabolism and a significant repression of genes encoding putative effectors. In S. vermifera, genes encoding hydrolytic enzymes were strongly induced. This antagonistic response was not activated during the tripartite interaction in barley roots. Instead, we observed a specific induction of S. vermifera genes involved in detoxification and redox homeostasis. Pathogen infection but not endophyte colonisation resulted in substantial host transcriptional reprogramming and activation of defence. In the presence of S. vermifera, pathogen infection and disease symptoms were significantly reduced despite no marked alterations of the plant transcriptional response. The activation of stress response genes and concomitant repression of putative effector gene expression in B. sorokiniana during confrontation with the endophyte suggest a reduction of the pathogen's virulence potential before host plant infection.
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Affiliation(s)
- Debika Sarkar
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Hanna Rovenich
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Ganga Jeena
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Shadab Nizam
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Alain Tissier
- Department of Cell and Metabolic Biology, Institute of Plant Biochemistry, 06120, Halle (Saale), Germany
| | - Gerd U Balcke
- Department of Cell and Metabolic Biology, Institute of Plant Biochemistry, 06120, Halle (Saale), Germany
| | - Lisa K Mahdi
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Michael Bonkowski
- Institute of Zoology, Terrestrial Ecology, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Gregor Langen
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
| | - Alga Zuccaro
- Botanical Institute, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, 50674, Cologne, Germany
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Wen Z, Raffaello T, Zeng Z, Pavicic M, Asiegbu FO. Chlorophyll fluorescence imaging for monitoring effects of Heterobasidion parviporum small secreted protein induced cell death and in planta defense gene expression. Fungal Genet Biol 2019; 126:37-49. [PMID: 30763724 DOI: 10.1016/j.fgb.2019.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/31/2019] [Accepted: 02/08/2019] [Indexed: 02/01/2023]
Abstract
Heterobasidion parviporum Niemelä & Korhonen is a necrotrophic fungal pathogen of Norway spruce (Picea abies). The H. parviporum genome encodes numerous necrotrophic small secreted proteins (SSP) which might be important for promoting and sustaining the disease development. However, their transcriptional dynamics and plant defense response during infection are largely unknown. In this study, we identified a necrotrophic SSP named HpSSP35.8 and its coding gene was highly expressed in the pre-symptomatic phase of the host (Norway spruce) infection. We explored the impact of HpSSP35.8 on non-host Nicotiana benthamiana using Agrobacterium-mediated transient expression system under visible spectrum RGB imaging and chlorophyll fluorescence imaging. The results showed that HpSSP35.8 triggered a form of SSP-associated programmed cell death, accompanied by a decrease in the plant photosynthetic activity. Defense-related genes including WRKY12, ethylene response factor (ERF1α) and a chitinase gene PR4 were up-regulated in both HpSSP35.8-N. benthamiana interaction and H. parviporum-Norway spruce pathosystem. This study also highlighted the potential to use the chlorophyll fluorescence imaging approach to monitor both the indirect effects of SSP and also for the selection of other potential effector-like protein candidates.
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Affiliation(s)
- Zilan Wen
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Tommaso Raffaello
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland
| | - Zhen Zeng
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Mirko Pavicic
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - Fred O Asiegbu
- Faculty of Agriculture and Forestry, P. O. Box 27, Latokartanonkaari 7, 00014, University of Helsinki, Helsinki, Finland; Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
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Haueisen J, Möller M, Eschenbrenner CJ, Grandaubert J, Seybold H, Adamiak H, Stukenbrock EH. Highly flexible infection programs in a specialized wheat pathogen. Ecol Evol 2019; 9:275-294. [PMID: 30680113 PMCID: PMC6342133 DOI: 10.1002/ece3.4724] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/21/2022] Open
Abstract
Many filamentous plant pathogens exhibit high levels of genomic variability, yet the impact of this variation on host-pathogen interactions is largely unknown. We have addressed host specialization in the wheat pathogen Zymoseptoria tritici. Our study builds on comparative analyses of infection and gene expression phenotypes of three isolates and reveals the extent to which genomic variation translates into phenotypic variation. The isolates exhibit genetic and genomic variation but are similarly virulent. By combining confocal microscopy, disease monitoring, staining of ROS, and comparative transcriptome analyses, we conducted a detailed comparison of the infection processes of these isolates in a susceptible wheat cultivar. We characterized four core infection stages: establishment, biotrophic growth, lifestyle transition, and necrotrophic growth and asexual reproduction that are shared by the three isolates. However, we demonstrate differentiated temporal and spatial infection development and significant differences in the expression profiles of the three isolates during the infection stages. More than 20% of the genes were differentially expressed and these genes were located significantly closer to transposable elements, suggesting an impact of epigenetic regulation. Further, differentially expressed genes were enriched in effector candidates suggesting that isolate-specific strategies for manipulating host defenses are present in Z. tritici. We demonstrate that individuals of a host-specialized pathogen have highly differentiated infection programs characterized by flexible infection development and functional redundancy. This illustrates how high genetic diversity in pathogen populations results in highly differentiated infection phenotypes, which fact needs to be acknowledged to understand host-pathogen interactions and pathogen evolution.
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Affiliation(s)
- Janine Haueisen
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Mareike Möller
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Christoph J. Eschenbrenner
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Jonathan Grandaubert
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Fungal Biology and PathogenicityInstitute PasteurParisFrance
| | - Heike Seybold
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Holger Adamiak
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
| | - Eva H. Stukenbrock
- Environmental Genomics GroupMax Planck Institute for Evolutionary BiologyPlönGermany
- Environmental Genomics GroupChristian‐Albrechts University KielKielGermany
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Citores L, Iglesias R, Ragucci S, Di Maro A, Ferreras JM. Antifungal Activity of α-Sarcin against Penicillium digitatum: Proposal of a New Role for Fungal Ribotoxins. ACS Chem Biol 2018; 13:1978-1982. [PMID: 29952541 DOI: 10.1021/acschembio.8b00410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Among the putative defense proteins that occur in fungi, one of the best studied is α-sarcin, produced by the mold Aspergillus giganteus. This protein is the most significant member of the ribotoxin family, which consists of extracellular rRNA ribonucleases that display cytotoxic activity toward animal cells. Ribotoxins are rRNA endonucleases that catalyze the hydrolysis of the phosphodiester bond between G4325 and A4326 from the rat 28S rRNA. The results of several experimental approaches have led to propose ribotoxins as insecticidal agents. In this work, we report that α-sarcin displays a strong antifungal activity against Penicillium digitatum, being able to enter into the cytosol where it inactivates the ribosomes, thus killing the cells and arresting the growth of the fungus. This is the first time that a ribotoxin has been found to display antifungal activity. Therefore, this protein could play, besides the already proposed insecticidal function, a role in nature as an antifungal agent.
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Affiliation(s)
- Lucía Citores
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain
| | - Rosario Iglesias
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain
| | - Sara Ragucci
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, I-81100 Caserta, Italy
| | - Antimo Di Maro
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, I-81100 Caserta, Italy
| | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain
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Bouton C, King RC, Chen H, Azhakanandam K, Bieri S, Hammond-Kosack KE, Kanyuka K. Foxtail mosaic virus: A Viral Vector for Protein Expression in Cereals. PLANT PHYSIOLOGY 2018; 177:1352-1367. [PMID: 29880705 PMCID: PMC6084670 DOI: 10.1104/pp.17.01679] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 05/30/2018] [Indexed: 05/08/2023]
Abstract
Rapid and cost-effective virus-derived transient expression systems for plants are invaluable in elucidating gene function and are particularly useful in plant species for which transformation-based methods are unavailable or are too time and labor demanding, such as wheat (Triticum aestivum) and maize (Zea mays). The virus-mediated overexpression (VOX) vectors based on Barley stripe mosaic virus and Wheat streak mosaic virus described previously for these species are incapable of expressing free recombinant proteins of more than 150 to 250 amino acids, are not suited for high-throughput screens, and have other limitations. In this study, we report the development of a VOX vector based on a monopartite single-stranded positive sense RNA virus, Foxtail mosaic virus (genus Potexvirus). In this vector, PV101, the gene of interest was inserted downstream of the duplicated subgenomic promoter of the viral coat protein gene, and the corresponding protein was expressed in its free form. The vector allowed the expression of a 239-amino acid-long GFP in both virus-inoculated and upper uninoculated (systemic) leaves of wheat and maize and directed the systemic expression of a larger approximately 600-amino acid protein, GUSPlus, in maize. Moreover, we demonstrated that PV101 can be used for in planta expression and functional analysis of apoplastic pathogen effector proteins such as the host-specific toxin ToxA of Parastagonospora nodorum Therefore, this VOX vector opens possibilities for functional genomics studies in two important cereal crops.
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Affiliation(s)
- Clément Bouton
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
| | - Robert C King
- Computational and Analytical Sciences, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
| | - Hongxin Chen
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
| | - Kasi Azhakanandam
- Seeds Research, Syngenta Biotechnology, Research Triangle Park, North Carolina 27709
| | | | - Kim E Hammond-Kosack
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
| | - Kostya Kanyuka
- Biointeractions and Crop Protection, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
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Snelders NC, Kettles GJ, Rudd JJ, Thomma BPHJ. Plant pathogen effector proteins as manipulators of host microbiomes? MOLECULAR PLANT PATHOLOGY 2018; 19:257-259. [PMID: 29368817 PMCID: PMC5817402 DOI: 10.1111/mpp.12628] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/05/2017] [Accepted: 10/09/2017] [Indexed: 05/23/2023]
Affiliation(s)
- Nick C. Snelders
- Laboratory of PhytopathologyWageningen University and Research6708 PB Wageningenthe Netherlands
| | - Graeme J. Kettles
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenHertfordshireAL5 2JQUK
| | - Jason J. Rudd
- Biointeractions & Crop ProtectionRothamsted ResearchHarpendenHertfordshireAL5 2JQUK
| | - Bart P. H. J. Thomma
- Laboratory of PhytopathologyWageningen University and Research6708 PB Wageningenthe Netherlands
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