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Qi Y, Li J, Mapuranga J, Zhang N, Chang J, Shen Q, Zhang Y, Wei J, Cui L, Liu D, Yang W. Wheat leaf rust fungus effector Pt13024 is avirulent to TcLr30. FRONTIERS IN PLANT SCIENCE 2023; 13:1098549. [PMID: 36726676 PMCID: PMC9885084 DOI: 10.3389/fpls.2022.1098549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/16/2022] [Indexed: 06/18/2023]
Abstract
Wheat leaf rust, caused by Puccinia triticina Eriks. (Pt), is a global wheat disease threatening wheat production. Dissecting how Pt effector proteins interact with wheat has great significance in understanding the pathogenicity mechanisms of Pt. In the study, the cDNA of Pt 13-5-72 interacting with susceptible cultivar Thatcher was used as template to amplify Pt13024 gene. The expression pattern and structure of Pt13024 were analyzed by qRT-PCR and online softwares. The secretion function of Pt13024 signal peptide was verified by the yeast system. Subcellular localization of Pt13024 was analyzed using transient expression on Nicotiana benthamiana. The verification that Pt13024 inhibited programmed cell death (PCD) was conducted on N. benthamiana and wheat. The deletion mutation of Pt13024 was used to identify the virulence function motif. The transient transformation of wheat mediated by the type III secretion system (TTSS) was used to analyze the activity of regulating the host defense response of Pt13024. Pt13024 gene silencing was performed by host-induced gene silencing (HIGS). The results showed that Pt13024 was identified as an effector and localized in the cytoplasm and nucleus on the N. benthamiana. It can inhibit PCD induced by the Bcl-2-associated X protein (BAX) from mice and infestans 1 (INF1) from Phytophthora infestans on N. benthamiana, and it can also inhibit PCD induced by DC3000 on wheat. The amino acids 22 to 41 at N-terminal of the Pt13024 are essential for the inhibition of programmed cell death (PCD) induced by BAX. The accumulation of reactive oxygen species and deposition of callose in near-isogenic line TcLr30, which is in Thatcher background with Lr30, induced by Pt13024 was higher than that in 41 wheat leaf rust-resistant near-isogenic lines (monogenic lines) with different resistance genes and Thatcher. Silencing of Pt13024 reduced the leaf rust resistance of Lr30 during the interaction between Pt and TcLr30. We can conclude that Pt13024 is avirulent to TcLr30 when Pt interacts with TcLr30. These findings lay the foundation for further investigations into the role of Pt effector proteins in pathogenesis and their regulatory mechanisms.
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Affiliation(s)
- Yue Qi
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jianyuan Li
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- College of Biological Sciences and Engineering, Xingtai University, Xingtai, China
| | - Johannes Mapuranga
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Na Zhang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Jiaying Chang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Qianhua Shen
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Yue Zhang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Dryland Farming Institute, Hebei Academy of Agricultural and Forestry Science, Hengshui, China
| | - Jie Wei
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
- Department of Agriculture and Animal Husbandry Engineering, Cangzhou Technical College, Cangzhou, China
| | - Liping Cui
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Daqun Liu
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
| | - Wenxiang Yang
- Department of Plant Pathology, Agricultural University of Hebei/Technological Innovation Center for Biological Control of Plant Diseases and Insect Pests of Hebei Province/National Engineering Research Center for Agriculture in Northern Mountainous Areas, Baoding, China
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Chepsergon J, Motaung TE, Moleleki LN. "Core" RxLR effectors in phytopathogenic oomycetes: A promising way to breeding for durable resistance in plants? Virulence 2021; 12:1921-1935. [PMID: 34304703 PMCID: PMC8516161 DOI: 10.1080/21505594.2021.1948277] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 12/30/2022] Open
Abstract
Phytopathogenic oomycetes are known to successfully infect their hosts due to their ability to secrete effector proteins. Of interest to many researchers are effectors with the N-terminal RxLR motif (Arginine-any amino acid-Leucine-Arginine). Owing to advances in genome sequencing, we can now comprehend the high level of diversity among oomycete effectors, and similarly, their conservation within and among species referred to here as "core" RxLR effectors (CREs). Currently, there is a considerable number of CREs that have been identified in oomycetes. Functional characterization of these CREs propose their virulence role with the potential of targeting central cellular processes that are conserved across diverse plant species. We reason that effectors that are highly conserved and recognized by the host, could be harnessed in engineering plants for durable as well as broad-spectrum resistance.
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Affiliation(s)
- Jane Chepsergon
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Thabiso E. Motaung
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Lucy Novungayo Moleleki
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria, Gauteng, South Africa
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Yan L, Wang Z, Song W, Fan P, Kang Y, Lei Y, Wan L, Huai D, Chen Y, Wang X, Sudini H, Liao B. Genome sequencing and comparative genomic analysis of highly and weakly aggressive strains of Sclerotium rolfsii, the causal agent of peanut stem rot. BMC Genomics 2021; 22:276. [PMID: 33863285 PMCID: PMC8052761 DOI: 10.1186/s12864-021-07534-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 03/15/2021] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Stem rot caused by Sclerotium rolfsii is a very important soil-borne disease of peanut. S. rolfsii is a necrotrophic plant pathogenic fungus with an extensive host range and worldwide distribution. It can infect peanut stems, roots, pegs and pods, leading to varied yield losses. S. rolfsii strains GP3 and ZY collected from peanut in different provinces of China exhibited a significant difference in aggressiveness on peanut plants by artificial inoculation test. In this study, de-novo genome sequencing of these two distinct strains was performed aiming to reveal the genomic basis of difference in aggressiveness. RESULTS Scleotium rolfsii strains GP3 and ZY, with weak and high aggressiveness on peanut plants, exhibited similar growth rate and oxalic acid production in laboratory. The genomes of S. rolfsii strains GP3 and ZY were sequenced by Pacbio long read technology and exhibited 70.51 Mb and 70.61 Mb, with contigs of 27 and 23, and encoded 17,097 and 16,743 gene models, respectively. Comparative genomic analysis revealed that the pathogenicity-related gene repertoires, which might be associated with aggressiveness, differed between GP3 and ZY. There were 58 and 45 unique pathogen-host interaction (PHI) genes in GP3 and ZY, respectively. The ZY strain had more carbohydrate-active enzymes (CAZymes) in its secretome than GP3, especially in the glycoside hydrolase family (GH), the carbohydrate esterase family (CBM), and the polysaccharide lyase family (PL). GP3 and ZY also had different effector candidates and putative secondary metabolite synthetic gene clusters. These results indicated that differences in PHI, secreted CAZymes, effectors and secondary metabolites may play important roles in aggressive difference between these two strains. CONCLUSIONS The data provided a further understanding of the S. rolfsii genome. Genomic comparison provided clues to the difference in aggressiveness of S. rolfsii strains.
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Affiliation(s)
- Liying Yan
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Zhihui Wang
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Wanduo Song
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Pengmin Fan
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Yanping Kang
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Yong Lei
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Liyun Wan
- College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045 China
| | - Dongxin Huai
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Yuning Chen
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Xin Wang
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Hari Sudini
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana 502324 India
| | - Boshou Liao
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, P.R. China, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
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He Q, Liu Y, Liang P, Liao X, Li X, Li X, Shi D, Liu W, Lin C, Zheng F, Miao W. A novel chorismate mutase from Erysiphe quercicola performs dual functions of synthesizing amino acids and inhibiting plant salicylic acid synthesis. Microbiol Res 2020; 242:126599. [PMID: 33010586 DOI: 10.1016/j.micres.2020.126599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 07/17/2020] [Accepted: 09/15/2020] [Indexed: 11/28/2022]
Abstract
Pathogens secrete effectors to establish a successful interaction with their host. It is well understood that plant pathogens recruit classically secreted chorismate mutase (Cmu) as an effector to disrupt plant salicylic acid (SA) synthesis. However, the identity and function of the Cmu effector from powdery mildew fungi remain unknown. Here, we identified a novel secreted Cmu effector, EqCmu, from rubber (Hevea brasiliensis Muell) powdery mildew fungus (Erysiphe quercicola). Unlike the classically secreted Cmu, EqCmu lack signal peptide, and exhibited characteristics of non-classically secreted proteins. EqCmu could fully complement a Saccharomyces cerevisiae ScAro7 mutant that was deficient in the synthesis of phenylalanine and tyrosine. In addition, transient expression of EqCmu could promote infection by Phytophthora capsici and reduce the levels of SA and the mRNA of PR1 gene in Nicotiana benthamiana in response to P. capsici infection, while confocal observations showed that EqCmu was localized within the cytoplasm and nucleus of transfected N. benthamiana leaf cells. These non-homologous systems assays provide evidences that EqCmu may serve as a "moonlighting" protein, which is not only a key enzyme in the synthesis of phenylalanine and tyrosine within fungal cells, but also has the function of regulating plant SA synthesis within plant cells. This is the first study to identify and functionally validate a candidate effector from E. quercicola. Overall, the non-classical secretion pathway is a novel mechanism for powdery mildew fungal effectors secretion and might play an important role in host-pathogen interactions.
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Affiliation(s)
- Qiguang He
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Yao Liu
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Peng Liang
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Xiaomiao Liao
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Xiang Li
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Xiao Li
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Dou Shi
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Wenbo Liu
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Chunhua Lin
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Fucong Zheng
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China
| | - Weiguo Miao
- College of Plant Protection, Hainan University, Haikou 570228, China; Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Hainan University), Ministry of Education, Haikou 570228, China.
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5
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Biotechnological Approaches: Gene Overexpression, Gene Silencing, and Genome Editing to Control Fungal and Oomycete Diseases in Grapevine. Int J Mol Sci 2020; 21:ijms21165701. [PMID: 32784854 PMCID: PMC7460970 DOI: 10.3390/ijms21165701] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 11/17/2022] Open
Abstract
Downy mildew, powdery mildew, and grey mold are some of the phytopathological diseases causing economic losses in agricultural crops, including grapevine, worldwide. In the current scenario of increasing global warming, in which the massive use of agrochemicals should be limited, the management of fungal disease has become a challenge. The knowledge acquired on candidate resistant (R) genes having an active role in plant defense mechanisms has allowed numerous breeding programs to integrate these traits into selected cultivars, even though with some limits in the conservation of the proper qualitative characteristics of the original clones. Given their gene-specific mode of action, biotechnological techniques come to the aid of breeders, allowing them to generate simple and fast modifications in the host, without introducing other undesired genes. The availability of efficient gene transfer procedures in grapevine genotypes provide valid tools that support the application of new breeding techniques (NBTs). The expertise built up over the years has allowed the optimization of these techniques to overexpress genes that directly or indirectly limit fungal and oomycetes pathogens growth or silence plant susceptibility genes. Furthermore, the downregulation of pathogen genes which act as virulence effectors by exploiting the RNA interference mechanism, represents another biotechnological tool that increases plant defense. In this review, we summarize the most recent biotechnological strategies optimized and applied on Vitis species, aimed at reducing their susceptibility to the most harmful fungal and oomycetes diseases. The best strategy for combating pathogenic organisms is to exploit a holistic approach that fully integrates all these available tools.
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Zhang Y, Xu K, Yu D, Liu Z, Peng C, Li X, Zhang J, Dong Y, Zhang Y, Tian P, Guo T, Li C. The Highly Conserved Barley Powdery Mildew Effector BEC1019 Confers Susceptibility to Biotrophic and Necrotrophic Pathogens in Wheat. Int J Mol Sci 2019; 20:ijms20184376. [PMID: 31489906 PMCID: PMC6770355 DOI: 10.3390/ijms20184376] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/02/2019] [Accepted: 09/03/2019] [Indexed: 01/11/2023] Open
Abstract
Effector proteins secreted by plant pathogens play important roles in promoting colonization. Blumeria effector candidate (BEC) 1019, a highly conserved metalloprotease of Blumeria graminis f. sp. hordei (Bgh), is essential for fungal haustorium formation, and silencing BEC1019 significantly reduces Bgh virulence. In this study, we found that BEC1019 homologs in B. graminis f. sp. tritici (Bgt) and Gaeumannomyces graminis var. tritici (Ggt) have complete sequence identity with those in Bgh, prompting us to investigate their functions. Transcript levels of BEC1019 were abundantly induced concomitant with haustorium formation in Bgt and necrosis development in Ggt-infected plants. BEC1019 overexpression considerably increased wheat susceptibility to Bgt and Ggt, whereas silencing this gene using host-induced gene silencing significantly enhanced wheat resistance to Bgt and Ggt, which was associated with hydrogen peroxide accumulation, cell death, and pathogenesis-related gene expression. Additionally, we found that the full and partial sequences of BEC1019 can trigger cell death in Nicotiana benthamiana leaves. These results indicate that Bgt and Ggt can utilize BEC1019 as a virulence effector to promote plant colonization, and thus these genes represent promising new targets in breeding wheat cultivars with broad-spectrum resistance.
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Affiliation(s)
- Yi Zhang
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Kedong Xu
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Deshui Yu
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Zhihui Liu
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Chunfeng Peng
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Xiaoli Li
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Ju Zhang
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Yinghui Dong
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Yazhen Zhang
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Pan Tian
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
| | - Tiancai Guo
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
| | - Chengwei Li
- Key Laboratory of Plant Genetics and Molecular Breeding, Zhoukou Normal University, Zhoukou 466001, China.
- Henan Engineering Research Center of Grain Crop Genome Editing, Henan Institute of Science and Technology, Xinxiang 453003, China.
- The Collaborative Innovation Center of Henan Food Crops, Agronomy College, Henan Agricultural University, Zhengzhou 450002, China.
- Henan Key Laboratory of Crop Molecular Breeding & Bioreactor, Zhoukou 466001, China.
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Bourras S, Kunz L, Xue M, Praz CR, Müller MC, Kälin C, Schläfli M, Ackermann P, Flückiger S, Parlange F, Menardo F, Schaefer LK, Ben-David R, Roffler S, Oberhaensli S, Widrig V, Lindner S, Isaksson J, Wicker T, Yu D, Keller B. The AvrPm3-Pm3 effector-NLR interactions control both race-specific resistance and host-specificity of cereal mildews on wheat. Nat Commun 2019; 10:2292. [PMID: 31123263 PMCID: PMC6533294 DOI: 10.1038/s41467-019-10274-1] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 05/03/2019] [Indexed: 12/25/2022] Open
Abstract
The wheat Pm3 resistance gene against the powdery mildew pathogen occurs as an allelic series encoding functionally different immune receptors which induce resistance upon recognition of isolate-specific avirulence (AVR) effectors from the pathogen. Here, we describe the identification of five effector proteins from the mildew pathogens of wheat, rye, and the wild grass Dactylis glomerata, specifically recognized by the PM3B, PM3C and PM3D receptors. Together with the earlier identified AVRPM3A2/F2, the recognized AVRs of PM3B/C, (AVRPM3B2/C2), and PM3D (AVRPM3D3) belong to a large group of proteins with low sequence homology but predicted structural similarities. AvrPm3b2/c2 and AvrPm3d3 are conserved in all tested isolates of wheat and rye mildew, and non-host infection assays demonstrate that Pm3b, Pm3c, and Pm3d are also restricting the growth of rye mildew on wheat. Furthermore, divergent AVR homologues from non-adapted rye and Dactylis mildews are recognized by PM3B, PM3C, or PM3D, demonstrating their involvement in host specificity.
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Affiliation(s)
- Salim Bourras
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland.
- Department of Forest Mycology and Plant Pathology, Division of Plant Pathology, Swedish University of Agricultural Sciences, 750 07, Uppsala, Sweden.
| | - Lukas Kunz
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Minfeng Xue
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China
- Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China
- College of Life Science, Wuhan University, Wuhan, 430072, China
| | - Coraline Rosalie Praz
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Marion Claudia Müller
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Carol Kälin
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Michael Schläfli
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Patrick Ackermann
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Simon Flückiger
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Francis Parlange
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Fabrizio Menardo
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | | | - Roi Ben-David
- Institute of Plant Science, ARO-Volcani Center, 50250, Bet Dagan, Israel
| | - Stefan Roffler
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Simone Oberhaensli
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Victoria Widrig
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Stefan Lindner
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Jonatan Isaksson
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland
| | - Dazhao Yu
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, 430064, China.
- Ministry of Agriculture Key Laboratory of Integrated Pest Management in Crops in Central China, Wuhan, 430064, China.
- College of Life Science, Wuhan University, Wuhan, 430072, China.
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, 8008, Zurich, Switzerland.
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Carter ME, Helm M, Chapman AVE, Wan E, Restrepo Sierra AM, Innes RW, Bogdanove AJ, Wise RP. Convergent Evolution of Effector Protease Recognition by Arabidopsis and Barley. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:550-565. [PMID: 30480480 DOI: 10.1094/mpmi-07-18-0202-fi] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Pseudomonas syringae cysteine protease AvrPphB activates the Arabidopsis resistance protein RPS5 by cleaving a second host protein, PBS1. AvrPphB induces defense responses in other plant species, but the genes and mechanisms mediating AvrPphB recognition in those species have not been defined. Here, we show that AvrPphB induces defense responses in diverse barley cultivars. We also show that barley contains two PBS1 orthologs, that their products are cleaved by AvrPphB, and that the barley AvrPphB response maps to a single locus containing a nucleotide-binding leucine-rich repeat (NLR) gene, which we termed AvrPphB Response 1 (Pbr1). Transient coexpression of PBR1 with wild-type AvrPphB but not with a protease inactive mutant triggered defense responses, indicating that PBR1 detects AvrPphB protease activity. Additionally, PBR1 coimmunoprecipitated with barley and Nicotiana benthamiana PBS1 proteins, suggesting mechanistic similarity to detection by RPS5. Lastly, we determined that wheat cultivars also recognize AvrPphB protease activity and contain two putative Pbr1 orthologs. Phylogenetic analyses showed, however, that Pbr1 is not orthologous to RPS5. Our results indicate that the ability to recognize AvrPphB evolved convergently and imply that selection to guard PBS1-like proteins occurs across species. Also, these results suggest that PBS1-based decoys may be used to engineer protease effector recognition-based resistance in barley and wheat.
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Affiliation(s)
- Morgan E Carter
- 1 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Matthew Helm
- 2 Department of Biology, Indiana University, Bloomington, IN, U.S.A
| | - Antony V E Chapman
- 3 Interdepartmental Genetics & Genomics Graduate Program and
- 4 Department of Plant Pathology & Microbiology, Iowa State University, Ames, IA, U.S.A
| | - Emily Wan
- 1 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Ana Maria Restrepo Sierra
- 1 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
- 5 Facultad de Ciencias, Universidad Nacional de Colombia Sede Medellín, Medellín, Colombia; and
| | - Roger W Innes
- 2 Department of Biology, Indiana University, Bloomington, IN, U.S.A
| | - Adam J Bogdanove
- 1 Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, U.S.A
| | - Roger P Wise
- 3 Interdepartmental Genetics & Genomics Graduate Program and
- 4 Department of Plant Pathology & Microbiology, Iowa State University, Ames, IA, U.S.A
- 6 Corn Insects and Crop Genetics Research, USDA-Agricultural Research Service, Ames, IA, U.S.A
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9
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Bourras S, Praz CR, Spanu PD, Keller B. Cereal powdery mildew effectors: a complex toolbox for an obligate pathogen. Curr Opin Microbiol 2018; 46:26-33. [DOI: 10.1016/j.mib.2018.01.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/22/2018] [Accepted: 01/31/2018] [Indexed: 01/25/2023]
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10
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Carter ME, Bogdanove AJ, Innes RW, Wise RP. A Confounding Effect of Bacterial Titer in a Type III Delivery-Based Assay of Eukaryotic Effector Function. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:1115-1116. [PMID: 29767549 DOI: 10.1094/mpmi-05-18-0128-le] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This letter describes a newly discovered confounding effect of bacterial titer in a previously published type III delivery-based assay of the fungal effector BEC1019. The original publication (Whigham et al. 2015) has been retracted as a consequence of this discovery. Here, we tabulate the affected and unaffected figures and conclusions in the original publication and briefly reflect on potential pitfalls to bear in mind when designing experiments that use bacterial type III secretion to characterize eukaryotic effectors.
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Affiliation(s)
- Morgan E Carter
- 1 Plant Pathology and Plant Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Adam J Bogdanove
- 1 Plant Pathology and Plant Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, U.S.A
| | - Roger W Innes
- 2 Department of Biology, Indiana University, Bloomington, IN 47405, U.S.A
| | - Roger P Wise
- 3 Corn Insects and Crop Genetics Research, USDA-Agricultural Research Service, Ames, IA 50011, U.S.A.; and
- 4 Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, U.S.A
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11
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Martínez-Cruz J, Romero D, De Vicente A, Pérez-García A. Transformation by growth onto agro-infiltrated tissues (TGAT), a simple and efficient alternative for transient transformation of the cucurbit powdery mildew pathogen Podosphaera xanthii. MOLECULAR PLANT PATHOLOGY 2018; 19:2502-2515. [PMID: 30073764 PMCID: PMC6638186 DOI: 10.1111/mpp.12722] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/21/2018] [Accepted: 06/24/2018] [Indexed: 05/30/2023]
Abstract
A major limitation of molecular studies in powdery mildew fungi (Erysiphales) is their genetic intractability. This is because they are obligate biotrophs. In these parasites, biotrophy is determined by the presence of haustoria, which are specialized structures of parasitism that play an essential role in the acquisition of nutrients and the deliverance of effectors. Podosphaera xanthii is the main causal agent of cucurbit powdery mildew and a major limitation for crop productivity. In a previous study using P. xanthii conidia, we showed, for the first time, the transformation of powdery mildew fungi by Agrobacterium tumefaciens. In this work, we hypothesized that the haustorium could also act as a natural route for the acquisition of DNA. To test our hypothesis, melon cotyledons were agro-infiltrated with A. tumefaciens that contained diverse transfer DNA (T-DNA) constructs harbouring different marker genes under the control of fungal promoters and, after elimination of the bacterium, the cotyledons were subsequently inoculated with P. xanthii conidia. Our results conclusively demonstrated the transfer of different T-DNAs from A. tumefaciens to P. xanthii, including two fungicide resistance markers (hph and tub2), a reporter gene (gfp) and a translational fusion (cfp-PxEC2). These results were further supported by the co-localization of translational fluorescent fusions of A. tumefaciens VirD2 and P. xanthii Rab5 proteins into small vesicles of haustorial and hyphal cells, suggesting endocytosis as the mechanism for T-DNA uptake, presumably by the haustorium. From our perspective, transformation by growth onto agro-infiltrated tissues (TGAT) is the easiest and most reliable method for the transient transformation of powdery mildew fungi.
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Affiliation(s)
- Jesús Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, 29071, Spain
| | - Diego Romero
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, 29071, Spain
| | - Antonio De Vicente
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, 29071, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Málaga, 29071, Spain
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12
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Hu Y, Liang Y, Zhang M, Tan F, Zhong S, Li X, Gong G, Chang X, Shang J, Tang S, Li T, Luo P. Comparative transcriptome profiling of Blumeria graminis f. sp. tritici during compatible and incompatible interactions with sister wheat lines carrying and lacking Pm40. PLoS One 2018; 13:e0198891. [PMID: 29975700 PMCID: PMC6033381 DOI: 10.1371/journal.pone.0198891] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/25/2018] [Indexed: 11/18/2022] Open
Abstract
Blumeria graminis f. sp. tritici (Bgt) is an obligate biotrophic fungus that causes wheat powdery mildew, which is a devastating disease in wheat. However, little is known about the pathogenesis of this fungus, and differences in the pathogenesis of the same pathogen at various resistance levels in hosts have not been determined. In the present study, leaf tissues of both Pm40-expressing hexaploid wheat line L658 and its Pm40-deficient sister line L958 were harvested at 0 (without inoculation), 6, 12, 24, 48 and 72 hours post-inoculation (hpi) with Bgt race 15 and then subjected to RNA sequencing (RNA-seq). In addition, we also observed changes in fungal growth morphology at the aforementioned time points. There was a high correlation between percentage of reads mapped to the Bgt reference genome and biomass of the fungus within the leaf tissue during the growth process. The percentage of mapped reads of Bgt in compatible interactions was significantly higher (at the p<0.05 level) than that of reads in incompatible interactions from 24 to 72 hpi. Further functional annotations indicated that expression levels of genes encoding H+-transporting ATPase, putative secreted effector proteins (PSEPs) and heat shock proteins (HSPs) were significantly up-regulated in compatible interactions compared with these levels in incompatible interactions, particularly at 72 hpi. Moreover, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis suggested that genes involved in the endocytosis pathway were also enriched in compatible interactions. Overall, genes encoding H+-transporting ATPase, PSEPs and HSPs possibly played crucial roles in successfully establishing the pathogenesis of compatible interactions during late stages of inoculation. The study results also indicated that endocytosis is likely to play a potential role in Bgt in establishing compatible interactions.
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Affiliation(s)
- Yuting Hu
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Yinping Liang
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Min Zhang
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Feiquan Tan
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shengfu Zhong
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xin Li
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Guoshu Gong
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiaoli Chang
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Jing Shang
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shengwen Tang
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Tao Li
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Peigao Luo
- Provincial Key Laboratory of Plant Breeding and Genetics, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan, China
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13
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Laur J, Ramakrishnan GB, Labbé C, Lefebvre F, Spanu PD, Bélanger RR. Effectors involved in fungal-fungal interaction lead to a rare phenomenon of hyperbiotrophy in the tritrophic system biocontrol agent-powdery mildew-plant. THE NEW PHYTOLOGIST 2018; 217:713-725. [PMID: 29044534 PMCID: PMC6079639 DOI: 10.1111/nph.14851] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/13/2017] [Indexed: 05/08/2023]
Abstract
Tritrophic interactions involving a biocontrol agent, a pathogen and a plant have been analyzed predominantly from the perspective of the biocontrol agent. We have conducted the first comprehensive transcriptomic analysis of all three organisms in an effort to understand the elusive properties of Pseudozyma flocculosa in the context of its biocontrol activity against Blumeria graminis f.sp. hordei as it parasitizes Hordeum vulgare. After inoculation of P. flocculosa, the tripartite interaction was monitored over time and samples collected for scanning electron microscopy and RNA sequencing. Based on our observations, P. flocculosa indirectly parasitizes barley, albeit transiently, by diverting nutrients extracted by B. graminis from barley leaves through a process involving unique effectors. This brings novel evidence that such molecules can also influence fungal-fungal interactions. Their release is synchronized with a higher expression of powdery mildew haustorial effectors, a sharp decline in the photosynthetic machinery of barley and a developmental peak in P. flocculosa. The interaction culminates with a collapse of B. graminis haustoria, thereby stopping P. flocculosa growth, as barley plants show higher metabolic activity. To conclude, our study has uncovered a complex and intricate phenomenon, described here as hyperbiotrophy, only achievable through the conjugated action of the three protagonists.
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Affiliation(s)
- Joan Laur
- Département de PhytologieUniversité LavalQuébecQCCanadaG1V 0A6
| | | | - Caroline Labbé
- Département de PhytologieUniversité LavalQuébecQCCanadaG1V 0A6
| | | | - Pietro D. Spanu
- Department of Life SciencesImperial College LondonSouth Kensington CampusLondonSW7 2AZUK
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14
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Qi M, Grayczyk JP, Seitz JM, Lee Y, Link TI, Choi D, Pedley KF, Voegele RT, Baum TJ, Whitham SA. Suppression or Activation of Immune Responses by Predicted Secreted Proteins of the Soybean Rust Pathogen Phakopsora pachyrhizi. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:163-174. [PMID: 29144203 DOI: 10.1094/mpmi-07-17-0173-fi] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Rust fungi, such as the soybean rust pathogen Phakopsora pachyrhizi, are major threats to crop production. They form specialized haustoria that are hyphal structures intimately associated with host-plant cell membranes. These haustoria have roles in acquiring nutrients and secreting effector proteins that manipulate host immune systems. Functional characterization of effector proteins of rust fungi is important for understanding mechanisms that underlie their virulence and pathogenicity. Hundreds of candidate effector proteins have been predicted for rust pathogens, but it is not clear how to prioritize these effector candidates for further characterization. There is a need for high-throughput approaches for screening effector candidates to obtain experimental evidence for effector-like functions, such as the manipulation of host immune systems. We have focused on identifying effector candidates with immune-related functions in the soybean rust fungus P. pachyrhizi. To facilitate the screening of many P. pachyrhizi effector candidates (named PpECs), we used heterologous expression systems, including the bacterial type III secretion system, Agrobacterium infiltration, a plant virus, and a yeast strain, to establish an experimental pipeline for identifying PpECs with immune-related functions and establishing their subcellular localizations. Several PpECs were identified that could suppress or activate immune responses in nonhost Nicotiana benthamiana, N. tabacum, Arabidopsis, tomato, or pepper plants.
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Affiliation(s)
- Mingsheng Qi
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - James P Grayczyk
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - Janina M Seitz
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Youngsill Lee
- 3 Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea; and
| | - Tobias I Link
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Doil Choi
- 3 Department of Plant Science, Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea; and
| | - Kerry F Pedley
- 4 Foreign Disease-Weed Science Research Unit, United States Department of Agriculture-Agricultural Research Service, Ft. Detrick, MD 21702, U.S.A
| | - Ralf T Voegele
- 2 Institut für Phytomedizin, Universität Hohenheim, Otto-Sander-Straße 5, 70599 Stuttgart, Germany
| | - Thomas J Baum
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
| | - Steven A Whitham
- 1 Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011, U.S.A
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15
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Deng CH, Plummer KM, Jones DAB, Mesarich CH, Shiller J, Taranto AP, Robinson AJ, Kastner P, Hall NE, Templeton MD, Bowen JK. Comparative analysis of the predicted secretomes of Rosaceae scab pathogens Venturia inaequalis and V. pirina reveals expanded effector families and putative determinants of host range. BMC Genomics 2017; 18:339. [PMID: 28464870 PMCID: PMC5412055 DOI: 10.1186/s12864-017-3699-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/11/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Fungal plant pathogens belonging to the genus Venturia cause damaging scab diseases of members of the Rosaceae. In terms of economic impact, the most important of these are V. inaequalis, which infects apple, and V. pirina, which is a pathogen of European pear. Given that Venturia fungi colonise the sub-cuticular space without penetrating plant cells, it is assumed that effectors that contribute to virulence and determination of host range will be secreted into this plant-pathogen interface. Thus the predicted secretomes of a range of isolates of Venturia with distinct host-ranges were interrogated to reveal putative proteins involved in virulence and pathogenicity. RESULTS Genomes of Venturia pirina (one European pear scab isolate) and Venturia inaequalis (three apple scab, and one loquat scab, isolates) were sequenced and the predicted secretomes of each isolate identified. RNA-Seq was conducted on the apple-specific V. inaequalis isolate Vi1 (in vitro and infected apple leaves) to highlight virulence and pathogenicity components of the secretome. Genes encoding over 600 small secreted proteins (candidate effectors) were identified, most of which are novel to Venturia, with expansion of putative effector families a feature of the genus. Numerous genes with similarity to Leptosphaeria maculans AvrLm6 and the Verticillium spp. Ave1 were identified. Candidates for avirulence effectors with cognate resistance genes involved in race-cultivar specificity were identified, as were putative proteins involved in host-species determination. Candidate effectors were found, on average, to be in regions of relatively low gene-density and in closer proximity to repeats (e.g. transposable elements), compared with core eukaryotic genes. CONCLUSIONS Comparative secretomics has revealed candidate effectors from Venturia fungal plant pathogens that attack pome fruit. Effectors that are putative determinants of host range were identified; both those that may be involved in race-cultivar and host-species specificity. Since many of the effector candidates are in close proximity to repetitive sequences this may point to a possible mechanism for the effector gene family expansion observed and a route to diversification via transposition and repeat-induced point mutation.
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Affiliation(s)
- Cecilia H. Deng
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
| | - Kim M. Plummer
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Plant Biosecurity Cooperative Research Centre, Bruce, ACT Australia
| | - Darcy A. B. Jones
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Present Address: The Centre for Crop and Disease Management, Curtin University, Bentley, Australia
| | - Carl H. Mesarich
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
- The School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Present Address: Institute of Agriculture & Environment, Massey University, Palmerston North, New Zealand
| | - Jason Shiller
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Present Address: INRA-Angers, Beaucouzé, Cedex, France
| | - Adam P. Taranto
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Plant Sciences Division, Research School of Biology, The Australian National University, Canberra, Australia
| | - Andrew J. Robinson
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Victoria, Australia
| | - Patrick Kastner
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
| | - Nathan E. Hall
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Victoria, Australia
| | - Matthew D. Templeton
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
- The School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Joanna K. Bowen
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
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16
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Derbyshire M, Denton-Giles M, Hegedus D, Seifbarghy S, Rollins J, van Kan J, Seidl MF, Faino L, Mbengue M, Navaud O, Raffaele S, Hammond-Kosack K, Heard S, Oliver R. The complete genome sequence of the phytopathogenic fungus Sclerotinia sclerotiorum reveals insights into the genome architecture of broad host range pathogens. Genome Biol Evol 2017; 9:593-618. [PMID: 28204478 PMCID: PMC5381539 DOI: 10.1093/gbe/evx030] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 01/16/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022] Open
Abstract
Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a “two-speed” genome. So described because their genomes contain alternating gene rich, repeat sparse and gene poor, repeat-rich regions. In fungi, the repeat-rich regions may be subjected to a process termed repeat-induced point mutation (RIP). Both repeat activity and RIP are thought to play a significant role in evolution of secreted virulence proteins, termed effectors. We present a complete genome sequence of S. sclerotiorum generated using Single Molecule Real-Time Sequencing technology with highly accurate annotations produced using an extensive RNA sequencing data set. We identified 70 effector candidates and have highlighted their in planta expression profiles. Furthermore, we characterized the genome architecture of S. sclerotiorum in comparison to plant pathogens that exhibit “two-speed” genomes. We show that there is a significant association between positions of secreted proteins and regions with a high RIP index in S. sclerotiorum but we did not detect a correlation between secreted protein proportion and GC content. Neither did we detect a negative correlation between CDS content and secreted protein proportion across the S. sclerotiorum genome. We conclude that S. sclerotiorum exhibits subtle signatures of enhanced mutation of secreted proteins in specific genomic compartments as a result of transposition and RIP activity. However, these signatures are not observable at the whole-genome scale.
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Affiliation(s)
- Mark Derbyshire
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Matthew Denton-Giles
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Dwayne Hegedus
- Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan, Canada
| | | | - Jeffrey Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL
| | - Jan van Kan
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Michael F. Seidl
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Luigi Faino
- Laboratory of Phytopathology, Wageningen University, The Netherlands
| | - Malick Mbengue
- LIPM Université de Toulouse INRA CNRS, Castanet-Tolosan, France
| | - Olivier Navaud
- LIPM Université de Toulouse INRA CNRS, Castanet-Tolosan, France
| | | | - Kim Hammond-Kosack
- Department of Plant Biology and Crop Sciences, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Stephanie Heard
- Department of Plant Pathology, University of Florida, Gainesville, FL
- Department of Plant Biology and Crop Sciences, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom
| | - Richard Oliver
- Centre for Crop and Disease Management Department of Environment and Agriculture, Curtin University, Bentley, Perth, Western Australia, Australia
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17
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Putative orthologs of Ustilago maydis effectors screened from the genome of sugarcane smut fungus - Sporisorium scitamineum. AUSTRALASIAN PLANT PATHOLOGY 2017. [DOI: 10.1007/s13313-017-0471-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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18
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Ramachandran SR, Yin C, Kud J, Tanaka K, Mahoney AK, Xiao F, Hulbert SH. Effectors from Wheat Rust Fungi Suppress Multiple Plant Defense Responses. PHYTOPATHOLOGY 2017; 107:75-83. [PMID: 27503371 DOI: 10.1094/phyto-02-16-0083-r] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (<300 amino acids), secreted proteins, with no predicted functions were selected for the HR suppression assay using Nicotiana benthamiana, in which each of the proteins were transiently expressed and evaluated for their ability to suppress HR caused by four cytotoxic effector-R gene combinations (Cp/Rx, ATR13/RPP13, Rpt2/RPS-2, and GPA/RBP-1) and one mutated R gene-Pto(Y207D). Nine out of twenty proteins, designated Shr1 to Shr9 (suppressors of hypersensitive response), were found to suppress HR in N. benthamiana. These effectors varied in the effector-R gene defenses they suppressed, indicating these pathogens can interfere with a variety of host defense pathways. In addition to HR suppression, effector Shr7 also suppressed PAMP-triggered immune response triggered by flg22. Finally, delivery of Shr7 through Pseudomonas fluorescens EtHAn suppressed nonspecific HR induced by Pseudomonas syringae DC3000 in wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.
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Affiliation(s)
- Sowmya R Ramachandran
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Chuntao Yin
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Joanna Kud
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Kiwamu Tanaka
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Aaron K Mahoney
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Fangming Xiao
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
| | - Scot H Hulbert
- First, second, fourth, fifth, and seventh authors: Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430; and third and sixth authors: Plant, Soil and Entomological Sciences, University of Idaho, Moscow, ID 83844-2339
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19
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Meyer M, Bourras S, Gervais J, Labadie K, Cruaud C, Balesdent MH, Rouxel T. Impact of biotic and abiotic factors on the expression of fungal effector-encoding genes in axenic growth conditions. Fungal Genet Biol 2016; 99:1-12. [PMID: 28034799 DOI: 10.1016/j.fgb.2016.12.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/15/2016] [Accepted: 12/22/2016] [Indexed: 12/31/2022]
Abstract
In phytopathogenic fungi, the expression of hundreds of small secreted protein (SSP)-encoding genes is induced upon primary infection of plants while no or a low level of expression is observed during vegetative growth. In some species such as Leptosphaeria maculans, this coordinated in-planta upregulation of SSP-encoding genes expression relies on an epigenetic control but the signals triggering gene expression in-planta are unknown. In the present study, biotic and abiotic factors that may relieve suppression of SSP-encoding gene expression during axenic growth of L. maculans were investigated. Some abiotic factors (temperature, pH) could have a limited effect on SSP gene expression. In contrast, two types of cellular stresses induced by antibiotics (cycloheximide, phleomycin) activated strongly the transcription of SSP genes. A transcriptomic analysis to cycloheximide exposure revealed that biological processes such as ribosome biosynthesis and rRNA processing were induced whereas important metabolic pathways such as glycogen and nitrogen metabolism, glycolysis and tricarboxylic acid cycle activity were down-regulated. A quantitatively different expression of SSP-encoding genes compared to plant infection was also detected. Interestingly, the same physico-chemical parameters as those identified here for L. maculans effectors were identified to regulate positively or negatively the expression of bacterial effectors. This suggests that apoplastic phytopathogens may react to similar physiological parameters for regulation of their effector genes.
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Affiliation(s)
- Michel Meyer
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France.
| | - Salim Bourras
- Université Paris-Sud, 91400 Orsay, France; Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Julie Gervais
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Karine Labadie
- Centre National de Séquençage, CEA-Institut de Génomique, GENOSCOPE, 2 rue Gaston Crémieux, 91057 Evry Cedex, France
| | - Corinne Cruaud
- Centre National de Séquençage, CEA-Institut de Génomique, GENOSCOPE, 2 rue Gaston Crémieux, 91057 Evry Cedex, France
| | - Marie-Hélène Balesdent
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
| | - Thierry Rouxel
- UMR BIOGER, INRA, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon, France
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20
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Laflamme B, Middleton M, Lo T, Desveaux D, Guttman DS. Image-Based Quantification of Plant Immunity and Disease. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:919-924. [PMID: 27996374 DOI: 10.1094/mpmi-07-16-0129-ta] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Measuring the extent and severity of disease is a critical component of plant pathology research and crop breeding. Unfortunately, existing visual scoring systems are qualitative, subjective, and the results are difficult to transfer between research groups, while existing quantitative methods can be quite laborious. Here, we present plant immunity and disease image-based quantification (PIDIQ), a quantitative, semi-automated system to rapidly and objectively measure disease symptoms in a biologically relevant context. PIDIQ applies an ImageJ-based macro to plant photos in order to distinguish healthy tissue from tissue that has yellowed due to disease. It can process a directory of images in an automated manner and report the relative ratios of healthy to diseased leaf area, thereby providing a quantitative measure of plant health that can be statistically compared with appropriate controls. We used the Arabidopsis thaliana-Pseudomonas syringae model system to show that PIDIQ is able to identify both enhanced plant health associated with effector-triggered immunity as well as elevated disease symptoms associated with effector-triggered susceptibility. Finally, we show that the quantitative results provided by PIDIQ correspond to those obtained via traditional in planta pathogen growth assays. PIDIQ provides a simple and effective means to nondestructively quantify disease from whole plants and we believe it will be equally effective for monitoring disease on excised leaves and stems.
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Affiliation(s)
- Bradley Laflamme
- 1 Department of Cell & Systems Biology, University of Toronto, Ontario, Canada; and
| | - Maggie Middleton
- 2 Centre for the Analysis of Genome Evolution & Function, University of Toronto
| | - Timothy Lo
- 1 Department of Cell & Systems Biology, University of Toronto, Ontario, Canada; and
| | - Darrell Desveaux
- 1 Department of Cell & Systems Biology, University of Toronto, Ontario, Canada; and
- 2 Centre for the Analysis of Genome Evolution & Function, University of Toronto
| | - David S Guttman
- 1 Department of Cell & Systems Biology, University of Toronto, Ontario, Canada; and
- 2 Centre for the Analysis of Genome Evolution & Function, University of Toronto
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21
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Wang M, Weiberg A, Lin FM, Thomma B, Huang HD, Jin H. Bidirectional cross-kingdom RNAi and fungal uptake of external RNAs confer plant protection. NATURE PLANTS 2016; 2:16151. [PMID: 27643635 PMCID: PMC5040644 DOI: 10.1038/nplants.2016.151] [Citation(s) in RCA: 393] [Impact Index Per Article: 49.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 09/01/2016] [Indexed: 05/17/2023]
Abstract
Aggressive fungal pathogens such as Botrytis and Verticillium spp. cause severe crop losses worldwide. We recently discovered that Botrytis cinerea delivers small RNAs (Bc-sRNAs) into plant cells to silence host immunity genes. Such sRNA effectors are mostly produced by Botrytis cinerea Dicer-like protein 1 (Bc-DCL1) and Bc-DCL2. Here we show that expressing sRNAs that target Bc-DCL1 and Bc-DCL2 in Arabidopsis and tomato silences Bc-DCL genes and attenuates fungal pathogenicity and growth, exemplifying bidirectional cross-kingdom RNAi and sRNA trafficking between plants and fungi. This strategy can be adapted to simultaneously control multiple fungal diseases. We also show that Botrytis can take up external sRNAs and double-stranded RNAs (dsRNAs). Applying sRNAs or dsRNAs that target Botrytis DCL1 and DCL2 genes on the surface of fruits, vegetables and flowers significantly inhibits grey mould disease. Such pathogen gene-targeting RNAs represent a new generation of environmentally friendly fungicides.
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Affiliation(s)
- Ming Wang
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Arne Weiberg
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Feng-Mao Lin
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu 300, Taiwan
| | - Bart Thomma
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Hsien-Da Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsin-Chu 300, Taiwan
| | - Hailing Jin
- Department of Plant Pathology and Microbiology, Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
- Correspondence to Hailing Jin.
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22
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Ahmed AA, Pedersen C, Thordal-Christensen H. The Barley Powdery Mildew Effector Candidates CSEP0081 and CSEP0254 Promote Fungal Infection Success. PLoS One 2016; 11:e0157586. [PMID: 27322386 PMCID: PMC4913928 DOI: 10.1371/journal.pone.0157586] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 06/01/2016] [Indexed: 11/19/2022] Open
Abstract
Effectors play significant roles in the success of pathogens. Recent advances in genome sequencing have revealed arrays of effectors and effector candidates from a wide range of plant pathogens. Yet, the vast majority of them remain uncharacterized. Among the ~500 Candidate Secreted Effector Proteins (CSEPs) predicted from the barley powdery mildew fungal genome, only a few have been studied and shown to have a function in virulence. Here, we provide evidence that CSEP0081 and CSEP0254 contribute to infection by the fungus. This was studied using Host-Induced Gene Silencing (HIGS), where independent silencing of the transcripts for these CSEPs significantly reduced the fungal penetration and haustoria formation rate. Both CSEPs are likely required during and after the formation of haustoria, in which their transcripts were found to be differentially expressed, rather than in epiphytic tissue. When expressed in barley leaf epidermal cells, both CSEPs appears to move freely between the cytosol and the nucleus, suggesting that their host targets locate in these cellular compartments. Collectively, our data suggest that, in addition to the previously reported effectors, the barley powdery mildew fungus utilizes these two CSEPs as virulence factors to enhance infection.
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Affiliation(s)
- Ali Abdurehim Ahmed
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Carsten Pedersen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Hans Thordal-Christensen
- Section for Plant and Soil Science, Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
- * E-mail:
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23
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Selin C, de Kievit TR, Belmonte MF, Fernando WGD. Elucidating the Role of Effectors in Plant-Fungal Interactions: Progress and Challenges. Front Microbiol 2016; 7:600. [PMID: 27199930 PMCID: PMC4846801 DOI: 10.3389/fmicb.2016.00600] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Accepted: 04/11/2016] [Indexed: 11/13/2022] Open
Abstract
Pathogenic fungi have diverse growth lifestyles that support fungal colonization on plants. Successful colonization and infection for all lifestyles depends upon the ability to modify living host plants to sequester the necessary nutrients required for growth and reproduction. Secretion of virulence determinants referred to as “effectors” is assumed to be the key governing factor that determines host infection and colonization. Effector proteins are capable of suppressing plant defense responses and alter plant physiology to accommodate fungal invaders. This review focuses on effector molecules of biotrophic and hemibiotrophic plant pathogenic fungi, and the mechanism required for the release and uptake of effector molecules by the fungi and plant cells, respectively. We also place emphasis on the discovery of effectors, difficulties associated with predicting the effector repertoire, and fungal genomic features that have helped promote effector diversity leading to fungal evolution. We discuss the role of specific effectors found in biotrophic and hemibiotrophic fungi and examine how CRISPR/Cas9 technology may provide a new avenue for accelerating our ability in the discovery of fungal effector function.
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Affiliation(s)
- Carrie Selin
- Department of Plant Science, University of Manitoba Winnipeg, MB, Canada
| | | | - Mark F Belmonte
- Department of Biological Sciences, University of Manitoba Winnipeg, MB, Canada
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24
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Giannakopoulou A, Bialas A, Kamoun S, Vleeshouwers VGAA. Plant immunity switched from bacteria to virus. Nat Biotechnol 2016; 34:391-2. [DOI: 10.1038/nbt.3538] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Kim SH, Qi D, Ashfield T, Helm M, Innes RW. Using decoys to expand the recognition specificity of a plant disease resistance protein. Science 2016; 351:684-7. [PMID: 26912853 DOI: 10.1126/science.aad3436] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Maintaining high crop yields in an environmentally sustainable manner requires the development of disease-resistant crop varieties. We describe a method to engineer disease resistance in plants by means of an endogenous disease resistance gene from Arabidopsis thaliana named RPS5, which encodes a nucleotide-binding leucine-rich repeat (NLR) protein. RPS5 is normally activated when a second host protein, PBS1, is cleaved by the pathogen-secreted protease AvrPphB. We show that the AvrPphB cleavage site within PBS1 can be substituted with cleavage sites for other pathogen proteases, which then enables RPS5 to be activated by these proteases, thereby conferring resistance to new pathogens. This "decoy" approach may be applicable to other NLR proteins and should enable engineering of resistance in plants to diseases for which we currently lack robust genetic resistance.
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Affiliation(s)
- Sang Hee Kim
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Dong Qi
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Tom Ashfield
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Matthew Helm
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Roger W Innes
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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26
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Bourras S, McNally KE, Müller MC, Wicker T, Keller B. Avirulence Genes in Cereal Powdery Mildews: The Gene-for-Gene Hypothesis 2.0. FRONTIERS IN PLANT SCIENCE 2016; 7:241. [PMID: 26973683 PMCID: PMC4771761 DOI: 10.3389/fpls.2016.00241] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/12/2016] [Indexed: 05/22/2023]
Abstract
The gene-for-gene hypothesis states that for each gene controlling resistance in the host, there is a corresponding, specific gene controlling avirulence in the pathogen. Allelic series of the cereal mildew resistance genes Pm3 and Mla provide an excellent system for genetic and molecular analysis of resistance specificity. Despite this opportunity for molecular research, avirulence genes in mildews remain underexplored. Earlier work in barley powdery mildew (B.g. hordei) has shown that the reaction to some Mla resistance alleles is controlled by multiple genes. Similarly, several genes are involved in the specific interaction of wheat mildew (B.g. tritici) with the Pm3 allelic series. We found that two mildew genes control avirulence on Pm3f: one gene is involved in recognition by the resistance protein as demonstrated by functional studies in wheat and the heterologous host Nicotiana benthamiana. A second gene is a suppressor, and resistance is only observed in mildew genotypes combining the inactive suppressor and the recognized Avr. We propose that such suppressor/avirulence gene combinations provide the basis of specificity in mildews. Depending on the particular gene combinations in a mildew race, different genes will be genetically identified as the "avirulence" gene. Additionally, the observation of two LINE retrotransposon-encoded avirulence genes in B.g. hordei further suggests that the control of avirulence in mildew is more complex than a canonical gene-for-gene interaction. To fully understand the mildew-cereal interactions, more knowledge on avirulence determinants is needed and we propose ways how this can be achieved based on recent advances in the field.
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27
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Bindschedler LV, Panstruga R, Spanu PD. Mildew-Omics: How Global Analyses Aid the Understanding of Life and Evolution of Powdery Mildews. FRONTIERS IN PLANT SCIENCE 2016; 7:123. [PMID: 26913042 PMCID: PMC4753294 DOI: 10.3389/fpls.2016.00123] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/22/2016] [Indexed: 05/21/2023]
Abstract
The common powdery mildew plant diseases are caused by ascomycete fungi of the order Erysiphales. Their characteristic life style as obligate biotrophs renders functional analyses in these species challenging, mainly because of experimental constraints to genetic manipulation. Global large-scale ("-omics") approaches are thus particularly valuable and insightful for the characterisation of the life and evolution of powdery mildews. Here we review the knowledge obtained so far from genomic, transcriptomic and proteomic studies in these fungi. We consider current limitations and challenges regarding these surveys and provide an outlook on desired future investigations on the basis of the various -omics technologies.
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Affiliation(s)
| | - Ralph Panstruga
- Unit of Plant Molecular Cell Biology, Institute for Biology I, RWTH Aachen UniversityAachen, Germany
- *Correspondence: Ralph Panstruga,
| | - Pietro D. Spanu
- Department of Life Sciences, Imperial College LondonLondon, UK
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28
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Xu W, Meng Y, Surana P, Fuerst G, Nettleton D, Wise RP. The knottin-like Blufensin family regulates genes involved in nuclear import and the secretory pathway in barley-powdery mildew interactions. FRONTIERS IN PLANT SCIENCE 2015; 6:409. [PMID: 26089830 PMCID: PMC4454880 DOI: 10.3389/fpls.2015.00409] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 05/21/2015] [Indexed: 05/24/2023]
Abstract
Plants have evolved complex regulatory mechanisms to control a multi-layered defense response to microbial attack. Both temporal and spatial gene expression are tightly regulated in response to pathogen ingress, modulating both positive and negative control of defense. BLUFENSINs, small knottin-like peptides in barley, wheat, and rice, are highly induced by attack from fungal pathogens, in particular, the obligate biotrophic fungus, Blumeria graminis f. sp. hordei (Bgh), causal agent of barley powdery mildew. Previous research indicated that Blufensin1 (Bln1) functions as a negative regulator of basal defense mechanisms. In the current report, we show that BLN1 and BLN2 can both be secreted to the apoplast and Barley stripe mosaic virus (BSMV)-mediated overexpression of Bln2 increases susceptibility of barley to Bgh. Bimolecular fluorescence complementation (BiFC) assays signify that BLN1 and BLN2 can interact with each other, and with calmodulin. We then used BSMV-induced gene silencing to knock down Bln1, followed by Barley1 GeneChip transcriptome analysis, to identify additional host genes influenced by Bln1. Analysis of differential expression revealed a gene set enriched for those encoding proteins annotated to nuclear import and the secretory pathway, particularly Importin α1-b and Sec61 γ subunits. Further functional analysis of these two affected genes showed that when silenced, they also reduced susceptibility to Bgh. Taken together, we postulate that Bln1 is co-opted by Bgh to facilitate transport of disease-related host proteins or effectors, influencing the establishment of Bgh compatibility on its barley host.
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Affiliation(s)
- Weihui Xu
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
| | - Yan Meng
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
| | - Priyanka Surana
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Bioinformatics and Computational Biology Graduate Program, Iowa State UniversityAmes, IA, USA
| | - Greg Fuerst
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Corn Insects and Crop Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Iowa State UniversityAmes, IA, USA
| | - Dan Nettleton
- Department of Statistics, Iowa State UniversityAmes, IA, USA
| | - Roger P. Wise
- Department of Plant Pathology and Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State UniversityAmes, IA, USA
- Corn Insects and Crop Genetics Research Unit, U.S. Department of Agriculture-Agricultural Research Service, Iowa State UniversityAmes, IA, USA
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