1
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Zhu Q, Ahmad A, Shi C, Tang Q, Liu C, Ouyang B, Deng Y, Li F, Cao X. Protein arginine methyltransferase 6 mediates antiviral immunity in plants. Cell Host Microbe 2024:S1931-3128(24)00273-7. [PMID: 39106871 DOI: 10.1016/j.chom.2024.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 04/19/2024] [Accepted: 07/12/2024] [Indexed: 08/09/2024]
Abstract
Viral suppressor RNA silencing (VSR) is essential for successful infection. Nucleotide-binding and leucine-rich repeat (NLR)-based and autophagy-mediated immune responses have been reported to target VSR as counter-defense strategies. Here, we report a protein arginine methyltransferase 6 (PRMT6)-mediated defense mechanism targeting VSR. The knockout and overexpression of PRMT6 in tomato plants lead to enhanced and reduced disease symptoms, respectively, during tomato bush stunt virus (TBSV) infection. PRMT6 interacts with and inhibits the VSR function of TBSV P19 by methylating its key arginine residues R43 and R115, thereby reducing its dimerization and small RNA-binding activities. Analysis of the natural tomato population reveals that two major alleles associated with high and low levels of PRMT6 expression are significantly associated with high and low levels of viral resistance, respectively. Our study establishes PRMT6-mediated arginine methylation of VSR as a mechanism of plant immunity against viruses.
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Affiliation(s)
- Qiangqiang Zhu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Ayaz Ahmad
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chunmei Shi
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Qi Tang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Chunyan Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Ouyang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Yingtian Deng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
| | - Feng Li
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China; Hubei Hongshan Laboratory, Wuhan, Hubei 430070, China.
| | - Xiaofeng Cao
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
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2
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Akinyuwa MF, Price BK, Kang SH. Characterization of the proteins encoded by a recently emerged cotton-infecting Polerovirus. Virus Genes 2024:10.1007/s11262-024-02086-3. [PMID: 38907176 DOI: 10.1007/s11262-024-02086-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 06/06/2024] [Indexed: 06/23/2024]
Abstract
The cotton leafroll dwarf virus (CLDV), an important viral pathogen responsible for substantial losses in cotton crops, has recently emerged in the United States (US). Although CLDV shares similarities with other members of the genus Polerovirus in terms of encoded proteins, their functional characteristics remain largely unexplored. In this study, we expressed and analyzed each protein encoded by CLDV to determine its intracellular localization using fluorescence protein fusion. We also evaluated their potential to induce plant responses, such as the induction of hypersensitive response-like necrosis and the generation of reactive oxygen species. Our findings show that the proteins encoded by CLDV exhibit comparable localization patterns and elicit similar robust plant responses as observed with cognate proteins from other viruses within the genus Polerovirus. This study contributes to our understanding of the functional repertoire of genes carried by Polerovirus members, particularly to CLDV that has recently emerged as a widespread viral pathogen infecting cotton in the US.
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Affiliation(s)
- Mary F Akinyuwa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA
- Corteva Agriscience, Indianapolis, IN, 46268, USA
| | - Bailee K Price
- College of Sciences and Mathematics, Auburn University, Auburn, AL, 36849, USA
- Whiddon College of Medicine, University of South Alabama, Mobile, AL, 36688, USA
| | - Sung-Hwan Kang
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, 36849, USA.
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3
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OuYang X, Wang L, Luo X, Li C, An X, Yao L, Huang W, Zhang Z, Zhang S, Liu Y, Wu S. Pepper vein yellow virus P0 protein triggers NbHERC3, NbBax, and NbCRR mediated hypersensitive response. J Basic Microbiol 2024; 64:e2400023. [PMID: 38558182 DOI: 10.1002/jobm.202400023] [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: 01/16/2024] [Revised: 02/12/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
P0 proteins encoded by the pepper vein yellow virus (PeVYV) are pathogenic factors that cause hypersensitive response (HR). However, the host gene expression related to PeVYV P0-induced HR has not been thoroughly studied. Transcriptomic technology was used to investigate the host pathways mediated by the PeVYV P0 protein to explore the molecular mechanisms underlying its function. We found 12,638 differentially expressed genes (DEGs); 6784 and 5854 genes were significantly upregulated and downregulated, respectively. Transcriptomic and reverse-transcription quantitative polymerase chain reaction (RT-qPCR) analyses revealed that salicylic acid (SA) and jasmonic acid (JA) synthesis-related gene expression was upregulated, and ethylene synthesis-related gene expression was downregulated. Ultrahigh performance liquid chromatography-tandem mass spectrometry was used to quantify SA and JA concentrations in Nicotiana benthamiana, and the P0 protein induced SA and JA biosynthesis. We then hypothesized that the pathogenic activity of the P0 protein might be owing to proteins related to host hormones in the SA and JA pathways, modulating host resistance at different times. Viral gene silencing suppression technology was used in N. benthamiana to characterize candidate proteins, and downregulating NbHERC3 (Homologous to E6-AP carboxy-terminus domain and regulator of choromosome condensation-1 dmain protein 3) accelerated cell necrosis in the host. The downregulation of NbCRR reduced cell death, while that of NbBax induced necrosis and curled heart leaves. Our findings indicate that NbHERC3, NbBax, and NbCRR are involved in P0 protein-driven cell necrosis.
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Affiliation(s)
- Xian OuYang
- Plant Protection College of Hunan Agricultural University, Changsha, China
| | - Lishuang Wang
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
| | - Xiangwen Luo
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Institute of Plant Protection of Hunan Academy of Agricultural Science, Changsha, China
| | - Chun Li
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
| | - Xingyu An
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
| | - Ling Yao
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
| | - Wei Huang
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
| | - Zhanhong Zhang
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Institute of Plant Protection of Hunan Academy of Agricultural Science, Changsha, China
| | - Songbai Zhang
- Plant Protection College of Hunan Agricultural University, Changsha, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Institute of Plant Protection of Hunan Academy of Agricultural Science, Changsha, China
| | - Yong Liu
- Plant Protection College of Hunan Agricultural University, Changsha, China
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Institute of Plant Protection of Hunan Academy of Agricultural Science, Changsha, China
| | - Shiping Wu
- Institute of Plant Protection of Guizhou Academy of Agricultural Science, Guiyang, China
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4
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Parperides E, El Mounadi K, Garcia‐Ruiz H. Induction and suppression of gene silencing in plants by nonviral microbes. MOLECULAR PLANT PATHOLOGY 2023; 24:1347-1356. [PMID: 37438989 PMCID: PMC10502822 DOI: 10.1111/mpp.13362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/22/2023] [Accepted: 05/23/2023] [Indexed: 07/14/2023]
Abstract
Gene silencing is a conserved mechanism in eukaryotes that dynamically regulates gene expression. In plants, gene silencing is critical for development and for maintenance of genome integrity. Additionally, it is a critical component of antiviral defence in plants, nematodes, insects, and fungi. To overcome gene silencing, viruses encode effectors that suppress gene silencing. A growing body of evidence shows that gene silencing and suppression of silencing are also used by plants during their interaction with nonviral pathogens such as fungi, oomycetes, and bacteria. Plant-pathogen interactions involve trans-kingdom movement of small RNAs into the pathogens to alter the function of genes required for their development and virulence. In turn, plant-associated pathogenic and nonpathogenic microbes also produce small RNAs that move trans-kingdom into host plants to disrupt pathogen defence through silencing of plant genes. The mechanisms by which these small RNAs move from the microbe to the plant remain poorly understood. In this review, we examine the roles of trans-kingdom small RNAs and silencing suppressors produced by nonviral microbes in inducing and suppressing gene silencing in plants. The emerging model is that gene silencing and suppression of silencing play critical roles in the interactions between plants and their associated nonviral microbes.
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Affiliation(s)
- Eric Parperides
- Department of Plant Pathology and Nebraska Center for VirologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
| | - Kaoutar El Mounadi
- Department of BiologyKutztown University of PennsylvaniaKutztownPennsylvaniaUSA
| | - Hernan Garcia‐Ruiz
- Department of Plant Pathology and Nebraska Center for VirologyUniversity of Nebraska‐LincolnLincolnNebraskaUSA
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5
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Piau M, Schmitt-Keichinger C. The Hypersensitive Response to Plant Viruses. Viruses 2023; 15:2000. [PMID: 37896777 PMCID: PMC10612061 DOI: 10.3390/v15102000] [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: 09/11/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/29/2023] Open
Abstract
Plant proteins with domains rich in leucine repeats play important roles in detecting pathogens and triggering defense reactions, both at the cellular surface for pattern-triggered immunity and in the cell to ensure effector-triggered immunity. As intracellular parasites, viruses are mostly detected intracellularly by proteins with a nucleotide binding site and leucine-rich repeats but receptor-like kinases with leucine-rich repeats, known to localize at the cell surface, have also been involved in response to viruses. In the present review we report on the progress that has been achieved in the last decade on the role of these leucine-rich proteins in antiviral immunity, with a special focus on our current understanding of the hypersensitive response.
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6
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Systematic mutagenesis of Polerovirus protein P0 reveals distinct and overlapping amino acid functions in Nicotiana glutinosa. Virology 2023; 578:24-34. [PMID: 36462495 DOI: 10.1016/j.virol.2022.11.005] [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: 08/01/2022] [Revised: 10/27/2022] [Accepted: 11/10/2022] [Indexed: 11/19/2022]
Abstract
The protein P0 serves as the viral suppressor of RNA silencing (VSR) for poleroviruses, but elicits the hypersensitive response (HR) in specific Nicotiana species. We subjected P0 proteins from turnip yellows virus (P0Tu) and potato leafroll virus (P0PL) to serial deletion and performed extensive site-directed mutagenesis of P0Tu. Most deletions of the N-terminus and many substitution mutations disrupted both HR elicitation and VSR activity. Two conserved blocks of amino acid residues were found to be associated with HR. A double lysine to arginine substitution in HR-specific block 1 caused P0Tu to elicit a more robust HR. Conversely, deletion or mutation of block 2 in the C-terminus preserved VSR activity, but impaired HR elicitation, allowing virus escape from Nicotiana glutinosa resistance when expressed in the heterologous potato virus X vector. Our observations suggest that P0 residues responsible for suppressing RNA silencing and eliciting HR have overlapping, but distinct functions.
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7
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Dou R, Huang Q, Hu T, Yu F, Hu H, Wang Y, Zhou X, Qian Y. Molecular Variation and Genomic Function of Citrus Vein Enation Virus. Int J Mol Sci 2022; 24:ijms24010412. [PMID: 36613855 PMCID: PMC9820537 DOI: 10.3390/ijms24010412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/18/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
In this study, we identified a new citrus vein enation virus (CVEV) isolate (named CVEV-DT1) through sRNA high-throughput sequencing and traditional sequencing. Phylogenetic analysis based on whole genome sequences of all known CVEV isolates revealed that CVEV-DT1 was in an evolutionary branch with other isolates from China. Molecular variation analysis showed that the single nucleotide variability along CVEV full-length sequences was less than 8%, with more transitions (60.55%) than transversions (39.43%), indicating a genetically homogeneous CVEV population. In addition, non-synonymous nucleotide mutations mainly occurred in ORF1 and ORF2. Based on disorder analysis of all encoded ORF by CVEV-DT1, we identified that the CVEV-DT1 coat protein (CP) formed spherical granules, mainly in the cell nucleus and partly throughout the cytoplasm, with liquid properties through subcellular localization and photobleaching assay. Furthermore, we also confirmed that the CVEV P0 protein has weak post-transcriptional RNA-silencing suppressor activity and could elicit a strong hypersensitive response (HR) in tobacco plants. Collectively, to the best of our knowledge, our study was the first to profile the genomic variation in all the reported CVEV isolates and reveal the functions of CVEV-DT1-encoded proteins.
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Affiliation(s)
- Runqiu Dou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Qingqing Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Tao Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Fengzhe Yu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Hongxia Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
- Correspondence: ; Tel.: +86-571-88982677
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8
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Comparative Analysis of Biological Characteristics among P0 Proteins from Different Brassica Yellows Virus Genotypes. BIOLOGY 2021; 10:biology10111076. [PMID: 34827069 PMCID: PMC8614689 DOI: 10.3390/biology10111076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary Polerovirus P0 proteins are multifunctional proteins. Besides their viral suppressor of RNA silencing (VSR) functions, several P0 proteins can induce a cell death phenotype within the infiltrated region of Nicotiana benthamiana or Nicotiana glutinosa. Recently, the Brassica yellows virus (BrYV) genotype A P0 protein (P0BrA) was identified as a strong viral suppressor of RNAi. In this study, we compared the features of the P0 proteins encoded by different genotypes of BrYV and revealed their difference in inducing cell death in N. benthamiana. Key residues in P0BrA for inducing cell death were also identified. We also showed that all three BrYV genotypes had synergistic interaction with PEMV 2 in N. benthamiana. This study provides theoretical guidance for controlling the viral disease caused by poleroviruses in the future. Abstract Brassica yellows virus (BrYV) is a tentative species of the genus Polerovirus, which has at least three genotypes (A, B, and C) in China. The P0 protein of BrYV-A (P0BrA) has been identified as a viral suppressor of RNA silencing (VSR), which can also induce cell death in infiltrated Nicotiana benthamiana leaves. In this study, we demonstrated that the cell death induced by P0BrA was accompanied by the accumulation of reactive oxygen species (ROS) and increased Pathogenesis-related protein genes-1 (PR1) expression. Meanwhile, this cell death phenotype was delayed by salicylic acid (SA) pretreatment. Biological function comparison of the three P0 proteins showed that transiently expressed P0BrB or P0BrC induced a significantly delayed and milder cell death response compared with P0BrA. However, like P0BrA, they also suppressed local and systemic RNA silencing. Six residues of P0BrA essential for inducing cell death were identified by comparative analysis and amino acid substitution assay. We also show that all three BrYV genotypes have synergistic interactions with pea enation mosaic virus 2 (PEMV 2) in N. benthamiana. This study provides theoretical guidance for controlling the viral disease caused by poleroviruses in the future.
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Wang L, Tian P, Yang X, Zhou X, Zhang S, Li C, Yang X, Liu Y. Key Amino Acids for Pepper Vein Yellows Virus P0 Protein Pathogenicity, Gene Silencing, and Subcellular Localization. Front Microbiol 2021; 12:680658. [PMID: 34589062 PMCID: PMC8475269 DOI: 10.3389/fmicb.2021.680658] [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] [Received: 03/15/2021] [Accepted: 05/28/2021] [Indexed: 11/13/2022] Open
Abstract
Pepper vein yellows virus (PeVYV) is a newly recognized Polerovirus extracted from Chinese pepper. The symptoms of PeVYV-infested pepper plants comprise intervein yellow staining, leaf curl formation and other malformations, and leaf internodal shrinkage, but the roles of the viral proteins remain undetermined. The P0 protein of the genus Polerovirus has established post-transcriptional gene silencing (PTGS) activity. This investigation focused on the PeVYV-encoded P0 protein and assessed its potential virulence capacity, PTGS activity, and tendencies to localize in the nucleus. This study revealed that P0 influenced the pathogenic properties of a specific heterologous potato virus X. In addition, P0 proteins impaired local gene silencing, although they did not regulate generalized gene silencing within Nicotiana benthamiana 16c plants. Furthermore, P0 proteins localized mainly in the nucleus, particularly in the nucleolus. P0 deletion mutagenesis demonstrated that the F-box motif (56–72 amino acids, AAs) of P0 was essential for symptom determination, inhibition of PTGS, and subcellular localization. Mutation analysis of the F-box motif of P0 protein indicated that AA 57 of the P0 protein was a pivotal site in symptom development and that AA 56 of the P0 protein was indispensable for inhibiting PTGS and subcellular localization. The outcomes obtained here suggest that further studies should be conducted on the molecular mechanisms of amino acids of the F-box domain of P0 protein in the interaction of PeVYV with plants.
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Affiliation(s)
- Lishuang Wang
- College of Plant Protection, Hunan Agricultural University, Changsha, China.,Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, China
| | - Peijie Tian
- College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China
| | - Songbai Zhang
- Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Chun Li
- Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, China
| | - Xuehui Yang
- Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, China
| | - Yong Liu
- College of Plant Protection, Hunan Agricultural University, Changsha, China.,Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha, China
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10
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Akhter MS, Nakahara KS, Masuta C. Resistance induction based on the understanding of molecular interactions between plant viruses and host plants. Virol J 2021; 18:176. [PMID: 34454519 PMCID: PMC8400904 DOI: 10.1186/s12985-021-01647-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/23/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Viral diseases cause significant damage to crop yield and quality. While fungi- and bacteria-induced diseases can be controlled by pesticides, no effective approaches are available to control viruses with chemicals as they use the cellular functions of their host for their infection cycle. The conventional method of viral disease control is to use the inherent resistance of plants through breeding. However, the genetic sources of viral resistance are often limited. Recently, genome editing technology enabled the publication of multiple attempts to artificially induce new resistance types by manipulating host factors necessary for viral infection. MAIN BODY In this review, we first outline the two major (R gene-mediated and RNA silencing) viral resistance mechanisms in plants. We also explain the phenomenon of mutations of host factors to function as recessive resistance genes, taking the eIF4E genes as examples. We then focus on a new type of virus resistance that has been repeatedly reported recently due to the widespread use of genome editing technology in plants, facilitating the specific knockdown of host factors. Here, we show that (1) an in-frame mutation of host factors necessary to confer viral resistance, sometimes resulting in resistance to different viruses and that (2) certain host factors exhibit antiviral resistance and viral-supporting (proviral) properties. CONCLUSION A detailed understanding of the host factor functions would enable the development of strategies for the induction of a new type of viral resistance, taking into account the provision of a broad resistance spectrum and the suppression of the appearance of resistance-breaking strains.
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Affiliation(s)
- Md Shamim Akhter
- Plant Pathology Division, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur, 1701, Bangladesh
| | - Kenji S Nakahara
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan
| | - Chikara Masuta
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Hokkaido, 060-8589, Japan.
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11
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Huang C. From Player to Pawn: Viral Avirulence Factors Involved in Plant Immunity. Viruses 2021; 13:v13040688. [PMID: 33923435 PMCID: PMC8073968 DOI: 10.3390/v13040688] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/09/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
In the plant immune system, according to the 'gene-for-gene' model, a resistance (R) gene product in the plant specifically surveils a corresponding effector protein functioning as an avirulence (Avr) gene product. This system differs from other plant-pathogen interaction systems, in which plant R genes recognize a single type of gene or gene family because almost all virus genes with distinct structures and functions can also interact with R genes as Avr determinants. Thus, research conducted on viral Avr-R systems can provide a novel understanding of Avr and R gene product interactions and identify mechanisms that enable rapid co-evolution of plants and phytopathogens. In this review, we intend to provide a brief overview of virus-encoded proteins and their roles in triggering plant resistance, and we also summarize current progress in understanding plant resistance against virus Avr genes. Moreover, we present applications of Avr gene-mediated phenotyping in R gene identification and screening of segregating populations during breeding processes.
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Affiliation(s)
- Changjun Huang
- Key Laboratory of Tobacco Biotechnological Breeding, National Tobacco Genetic Engineering Research Center, Yunnan Academy of Tobacco Agricultural Sciences, Kunming 650021, China
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12
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Sun Q, Zhuo T, Zhao T, Zhou C, Li Y, Wang Y, Li D, Yu J, Han C. Functional Characterization of RNA Silencing Suppressor P0 from Pea Mild Chlorosis Virus. Int J Mol Sci 2020; 21:E7136. [PMID: 32992609 PMCID: PMC7582759 DOI: 10.3390/ijms21197136] [Citation(s) in RCA: 4] [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: 09/01/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 01/22/2023] Open
Abstract
To counteract host antiviral RNA silencing, plant viruses encode numerous viral suppressors of RNA silencing (VSRs). P0 proteins have been identified as VSRs in many poleroviruses. However, their suppressor function has not been fully characterized. Here, we investigated the function of P0 from pea mild chlorosis virus (PMCV) in the suppression of local and systemic RNA silencing via green fluorescent protein (GFP) co-infiltration assays in wild-type and GFP-transgenic Nicotiana benthamiana (line 16c). Amino acid deletion analysis showed that N-terminal residues Asn 2 and Val 3, but not the C-terminus residues from 230-270 aa, were necessary for PMCV P0 (P0PM) VSR activity. P0PM acted as an F-box protein, and triple LPP mutation (62LPxx79P) at the F-box-like motif abolished its VSR activity. In addition, P0PM failed to interact with S-phase kinase-associated protein 1 (SKP1), which was consistent with previous findings of P0 from potato leafroll virus. These data further support the notion that VSR activity of P0 is independent of P0-SKP1 interaction. Furthermore, we examined the effect of P0PM on ARGONAUTE1 (AGO1) protein stability, and co-expression analysis showed that P0PM triggered AGO1 degradation. Taken together, our findings suggest that P0PM promotes degradation of AGO1 to suppress RNA silencing independent of SKP1 interaction.
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Affiliation(s)
- Qian Sun
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China;
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Tao Zhuo
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Tianyu Zhao
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Cuiji Zhou
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Yuanyuan Li
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Ying Wang
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Dawei Li
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Jialin Yu
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Chenggui Han
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
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Montenegro Alonso AP, Ali S, Song X, Linning R, Bakkeren G. UhAVR1, an HR-Triggering Avirulence Effector of Ustilago hordei, Is Secreted via the ER-Golgi Pathway, Localizes to the Cytosol of Barley Cells during in Planta-Expression, and Contributes to Virulence Early in Infection. J Fungi (Basel) 2020; 6:E178. [PMID: 32961976 PMCID: PMC7559581 DOI: 10.3390/jof6030178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022] Open
Abstract
The basidiomycete Ustilago hordei causes covered smut disease of barley and oats. Virulence effectors promoting infection and supporting pathogen lifestyle have been described for this fungus. Genetically, six avirulence genes are known and one codes for UhAVR1, the only proven avirulence effector identified in smuts to date that triggers complete immunity in barley cultivars carrying resistance gene Ruh1. A prerequisite for resistance breeding is understanding the host targets and molecular function of UhAVR1. Analysis of this effector upon natural infection of barley coleoptiles using teliospores showed that UhAVR1 is expressed during the early stages of fungal infection where it leads to HR triggering in resistant cultivars or performs its virulence function in susceptible cultivars. Fungal secretion of UhAVR1 is directed by its signal peptide and occurs via the BrefeldinA-sensitive ER-Golgi pathway in cell culture away from its host. Transient in planta expression of UhAVR1 in barley and a nonhost, Nicotiana benthamiana, supports a cytosolic localization. Delivery of UhAVR1 via foxtail mosaic virus or Pseudomonas species in both barley and N. benthamiana reveals a role in suppressing components common to both plant systems of Effector- and Pattern-Triggered Immunity, including necrosis triggered by Agrobacterium-delivered cell death inducers.
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Affiliation(s)
- Ana Priscilla Montenegro Alonso
- Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada;
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Shawkat Ali
- Agriculture and Agri-Food Canada, Kentville Research and Development Centre, Kentville, NS B4N 1J5, Canada;
| | - Xiao Song
- Sandstone Pharmacies Glenmore Landing Calgary-Compounding, 167D, 1600–90 Ave SW Calgary, AB T2V 5A8, Canada;
| | - Rob Linning
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
| | - Guus Bakkeren
- Agriculture and Agri-Food Canada, Summerland Research and Development Centre, Summerland, BC V0H 1Z0, Canada;
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Arena GD, Ramos-González PL, Falk BW, Casteel CL, Freitas-Astúa J, Machado MA. Plant Immune System Activation Upon Citrus Leprosis Virus C Infection Is Mimicked by the Ectopic Expression of the P61 Viral Protein. FRONTIERS IN PLANT SCIENCE 2020; 11:1188. [PMID: 32849736 PMCID: PMC7427430 DOI: 10.3389/fpls.2020.01188] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/22/2020] [Indexed: 05/04/2023]
Abstract
Citrus leprosis virus C (CiLV-C, genus Cilevirus, family Kitaviridae) is an atypical virus that does not spread systemically in its plant hosts. Upon its inoculation by Brevipalpus mites, only localized lesions occur, and the infection remains limited to cells around mite feeding sites. Here, we aimed to gain insights into the putative causes of viral unfitness in plants by expanding the limited knowledge of the molecular mechanisms underlying plant/kitavirid interactions. Firstly, we quantified the CiLV-C viral RNAs during the infection in Arabidopsis thaliana plants using RT-qPCR and systematized it by defining three stages of distinguishing subgenomic and genomic RNA accumulation: i) 0-24 h after infestation, ii) 2-4 days after infestation (dai), and iii) 6-10 dai. Accordingly, the global plant response to CiLV-C infection was assessed by RNA-Seq at each period. Results indicated a progressive reprogramming of the plant transcriptome in parallel to the increasing viral loads. Gene ontology enrichment analysis revealed the induction of cell growth-related processes at the early stages of the infection and the triggering of the SA-mediated pathway, ROS burst and hypersensitive response (HR) at the presymptomatic stage. Conversely, infected plants downregulated JA/ET-mediated pathways and processes involved in the primary metabolism including photosynthesis. Marker genes of unfolded protein response were also induced, suggesting a contribution of the endoplasmic reticulum stress to the cell death caused by the viral infection. Finally, we transiently expressed CiLV-C proteins in Nicotiana benthamiana plants to undertake their roles in the elicited plant responses. Expression of the CiLV-C P61 protein consistently triggered ROS burst, upregulated SA- and HR-related genes, increased SA levels, reduced JA levels, and caused cell death. Mimicry of responses typically observed during CiLV-C-plant interaction indicates P61 as a putative viral effector causing the HR-like symptoms associated with the infection. Our data strengthen the hypothesis that symptoms of CiLV-C infection might be the outcome of a hypersensitive-like response during an incompatible interaction. Consequently, the locally restricted infection of CiLV-C, commonly observed across infections by kitavirids, supports the thesis that these viruses, likely arising from an ancestral arthropod-infecting virus, are unable to fully circumvent plant defenses.
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Affiliation(s)
- Gabriella D. Arena
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, Brazil
- Escola Superior de Agricultura Luiz de Queiroz (ESALQ), Universidade de São Paulo, Piracicaba, Brazil
- Laboratório de Biologia Molecular Aplicada, Instituto Biológico, São Paulo, Brazil
| | - Pedro Luis Ramos-González
- Laboratório de Biologia Molecular Aplicada, Instituto Biológico, São Paulo, Brazil
- *Correspondence: Pedro Luis Ramos-González, ; Juliana Freitas-Astúa,
| | - Bryce W. Falk
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| | - Clare L. Casteel
- School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Juliana Freitas-Astúa
- Laboratório de Biologia Molecular Aplicada, Instituto Biológico, São Paulo, Brazil
- Laboratório de Virologia Vegetal, Embrapa Mandioca e Fruticultura, Cruz das Almas, Brazil
- *Correspondence: Pedro Luis Ramos-González, ; Juliana Freitas-Astúa,
| | - Marcos A. Machado
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas, Cordeirópolis, Brazil
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15
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Wang X, Luo C, Xu Y, Zhang C, Bao M, Dou J, Wang Q, Cheng Y. Expression of the p24 silencing suppressor of Grapevine leafroll-associated virus 2 from Potato virus X or Barley stripe mosaic virus vector elicits hypersensitive responses in Nicotiana benthamiana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 142:34-42. [PMID: 31255907 DOI: 10.1016/j.plaphy.2019.06.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/24/2019] [Accepted: 06/23/2019] [Indexed: 06/09/2023]
Abstract
The 24-kDa protein (p24) encoded by Grapevine leafroll-associated virus 2 (GLRaV-2) is an RNA-silencing suppressor (RSS), but its effect on active viral infection is unclear. Using a Potato virus X (PVX)-based expression system, we demonstrated that p24 elicits lethal systemic necrosis in Nicotiana benthamiana, sharing typical characteristics of the hypersensitive response (HR), and that NbRAR1 (a cytoplasmic Zn2+-binding protein) is involved in the PVX-p24-mediated systemic necrosis. Moreover, expression of p24 from Barley stripe mosaic virus (BSMV) vector triggered local necrosis in infiltrated patches of N. benthamiana, likely inhibiting viral systemic spread. By deletion analysis, we demonstrated that amino acids (aa) 1 to 180, which are located in the region (aa 1-188) previously shown to be necessary for p24's RSS activity, is sufficient for p24 to elicit systemic necrosis in the context of PVX infection. Using substitution mutants, we revealed that silencing-suppression-defective mutants R2A and W54A induce only a mild necrotic response; two mutants without self-interaction ability previously shown to lose or retain weak suppression function also displayed decreased pathogenicity: W149A without RSS activity elicited a mild necrotic response, whereas V162H/L169H/L170H which retains weak RSS activity was able to induce systemic necrosis, but with a 1- to 2-day delay. Taken together, p24 plays an important role in GLRaV-2 pathogenesis, triggering HR-like necrosis in N. benthamiana plants when expressed from PVX or BSMV vector; both the silencing suppression and self-interaction are crucial for p24's pathogenicity activity, and the region of p24 for determining systemic necrosis is mapped to aa 1-180.
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Affiliation(s)
- Xianyou Wang
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China
| | - Chen Luo
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China
| | - Yanfei Xu
- DeLaval Tianjin Company, Tianjin, 300308, China
| | - Chenwei Zhang
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China
| | - Mian Bao
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China
| | - Junjie Dou
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China
| | - Qi Wang
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Yuqin Cheng
- Department of Pomology, China Agricultural University, Beijing, 100193, China; Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing, 100083, China.
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Adhab M, Angel C, Rodriguez A, Fereidouni M, Király L, Scheets K, Schoelz JE. Tracing the Lineage of Two Traits Associated with the Coat Protein of the Tombusviridae: Silencing Suppression and HR Elicitation in Nicotiana Species. Viruses 2019; 11:E588. [PMID: 31261652 PMCID: PMC6669612 DOI: 10.3390/v11070588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 11/16/2022] Open
Abstract
In this paper we have characterized the lineage of two traits associated with the coat proteins (CPs) of the tombusvirids: Silencing suppression and HR elicitation in Nicotiana species. We considered that the tombusvirid CPs might collectively be considered an effector, with the CP of each CP-encoding species comprising a structural variant within the family. Thus, a phylogenetic analysis of the CP could provide insight into the evolution of a pathogen effector. The phylogeny of the CP of tombusvirids indicated that CP representatives of the family could be divided into four clades. In two separate clades the CP triggered a hypersensitive response (HR) in Nicotiana species of section Alatae but did not have silencing suppressor activity. In a third clade the CP had a silencing suppressor activity but did not have the capacity to trigger HR in Nicotiana species. In the fourth clade, the CP did not carry either function. Our analysis illustrates how structural changes that likely occurred in the CP effector of progenitors of the current genera led to either silencing suppressor activity, HR elicitation in select Nicotiana species, or neither trait.
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Affiliation(s)
- Mustafa Adhab
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
- Department of Plant Protection, University of Baghdad, 10071 Baghdad, Iraq
| | - Carlos Angel
- National Coffee Research Center-Cenicafe, Planalto, km. 4, Vía antigua Chinchiná-Manizales, Manizales (Caldes), Colombia
| | - Andres Rodriguez
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | | | - Lóránt Király
- Department of Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1022 Budapest, Herman Ottó str. 15, Hungary
| | - Kay Scheets
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK 74078, USA
| | - James E Schoelz
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA.
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Boccardo NA, Segretin ME, Hernandez I, Mirkin FG, Chacón O, Lopez Y, Borrás-Hidalgo O, Bravo-Almonacid FF. Expression of pathogenesis-related proteins in transplastomic tobacco plants confers resistance to filamentous pathogens under field trials. Sci Rep 2019; 9:2791. [PMID: 30808937 PMCID: PMC6391382 DOI: 10.1038/s41598-019-39568-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 01/25/2019] [Indexed: 01/18/2023] Open
Abstract
Plants are continuously challenged by pathogens, affecting most staple crops compromising food security. They have evolved different mechanisms to counterattack pathogen infection, including the accumulation of pathogenesis-related (PR) proteins. These proteins have been implicated in active defense, and their overexpression has led to enhanced resistance in nuclear transgenic plants, although in many cases constitutive expression resulted in lesion-mimic phenotypes. We decided to evaluate plastid transformation as an alternative to overcome limitations observed for nuclear transgenic technologies. The advantages include the possibilities to express polycistronic RNAs, to obtain higher protein expression levels, and the impeded gene flow due to the maternal inheritance of the plastome. We transformed Nicotiana tabacum plastids to co-express the tobacco PR proteins AP24 and β-1,3-glucanase. Transplastomic tobacco lines were characterized and subsequently challenged with Rhizoctonia solani, Peronospora hyoscyami f.sp. tabacina and Phytophthora nicotianae. Results showed that transplastomic plants expressing AP24 and β-1,3-glucanase are resistant to R. solani in greenhouse conditions and, furthermore, they are protected against P.hyoscyami f.sp. tabacina and P. nicotianae in field conditions under high inoculum pressure. Our results suggest that plastid co- expression of PR proteins AP24 and β-1,3-glucanase resulted in enhanced resistance against filamentous pathogens.
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Affiliation(s)
- Noelia Ayelen Boccardo
- Laboratorio de Biotecnología Vegetal, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), (C1428ADN), Ciudad Autónoma de Buenos Aires, Argentina
| | - María Eugenia Segretin
- Laboratorio de Biotecnología Vegetal, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), (C1428ADN), Ciudad Autónoma de Buenos Aires, Argentina.
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, (C1428EGA), Ciudad Autónoma de Buenos Aires, Argentina.
| | - Ingrid Hernandez
- Centro de Ingeniería Genética y Biotecnología (CIGB), (10600), La Habana, Cuba
| | - Federico Gabriel Mirkin
- Laboratorio de Biotecnología Vegetal, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), (C1428ADN), Ciudad Autónoma de Buenos Aires, Argentina
| | - Osmani Chacón
- Centro de Ingeniería Genética y Biotecnología (CIGB), (10600), La Habana, Cuba
| | - Yunior Lopez
- Centro de Ingeniería Genética y Biotecnología (CIGB), (10600), La Habana, Cuba
| | - Orlando Borrás-Hidalgo
- Centro de Ingeniería Genética y Biotecnología (CIGB), (10600), La Habana, Cuba
- Shandong Provincial Key Laboratory of Microbial Engineering, School of Biotechnology, Qi Lu University of Technology, Jinan, (250353), P.R. China
| | - Fernando Félix Bravo-Almonacid
- Laboratorio de Biotecnología Vegetal, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres" (INGEBI-CONICET), (C1428ADN), Ciudad Autónoma de Buenos Aires, Argentina.
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Buenos Aires, (B1876BXD), Argentina.
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18
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Rashid MO, Zhang XY, Wang Y, Li DW, Yu JL, Han CG. The Three Essential Motifs in P0 for Suppression of RNA Silencing Activity of Potato leafroll virus Are Required for Virus Systemic Infection. Viruses 2019; 11:E170. [PMID: 30791535 PMCID: PMC6410027 DOI: 10.3390/v11020170] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/14/2019] [Accepted: 02/16/2019] [Indexed: 12/19/2022] Open
Abstract
Higher plants exploit posttranscriptional gene silencing as a defense mechanism against virus infection by the RNA degradation system. Plant RNA viruses suppress posttranscriptional gene silencing using their encoded proteins. Three important motifs (F-box-like motif, G139/W140/G141-like motif, and C-terminal conserved region) in P0 of Potato leafroll virus (PLRV) were reported to be essential for suppression of RNA silencing activity. In this study, Agrobacterium-mediated transient experiments were carried out to screen the available amino acid substitutions in the F-box-like motif and G139/W140/G141-like motif that abolished the RNA silencing suppression activity of P0, without disturbing the P1 amino acid sequence. Subsequently, four P0 defective mutants derived from a full-length cDNA clone of PLRV (L76F and W87R substitutions in the F-box-like motif, G139RRR substitution in the G139/W140/G141-like motif, and F220R substitution in the C-terminal conserved region) were successfully generated by reverse PCR and used to investigate the impact of these substitutions on PLRV infectivity. The RT-PCR and western blot analysis revealed that these defective mutants affected virus accumulation in inoculated leaves and systemic movement in Nicotiana benthamiana as well as in its natural hosts, potato and black nightshade. These results further demonstrate that the RNA silencing suppressor of PLRV is required for PLRV accumulation and systemic infection.
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Affiliation(s)
- Mamun-Or Rashid
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Xiao-Yan Zhang
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Ying Wang
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Da-Wei Li
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Jia-Lin Yu
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Cheng-Gui Han
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
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Ma X, Hong N, Moffett P, Zhou Y, Wang G. Functional analysis of apple stem pitting virus coat protein variants. Virol J 2019; 16:20. [PMID: 30736799 PMCID: PMC6368714 DOI: 10.1186/s12985-019-1126-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 01/28/2019] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Although the canonical function of viral coat protein (CP) is to encapsidate the viral genome, they have come to be recognized as multifunctional proteins, involved in almost every stage of the viral infection cycle. However, CP functions of Apple stem pitting virus (ASPV) has not been comprehensively documented. This study aimed to characterize the functions of ASPV CP and any functional diversification caused by sequence diversity of six ASPV CP variants and studied their biological, serological, pathogenic and viral suppressor of RNA silencing (VSR) functions. METHODS Six ASPV CP variants that have previously been shown to belong to different subgroups were selected here to study their diversity functions. Agrobacterium mediated infiltration (Agroinfiltration) was used to express YFP-ASPV-CPs in Nicotiana. benthamiana and infect Nicotiana. occidental with PVX-ASPV-CPs in. Confocal microscopy was used to detect YFP-ASPV-CPs florescence. CPs expressed in Escherichia coli BL21 (DE3) were induced by IPTG. RESULTS In this study, we showed that recombinant CPs expressed in Escherichia coli BL21 (DE3) had different levels of serological reactivity to three anti-ASPV antibodies used to detect ASPV. Furthermore, fusion CPs with YFP (YFP-CPs) expressed in N. benthamiana cells differed in their ability to form aggregates. We also showed that ASPV isolates that harbour these CPs induced different biological symptoms on its herbaceous host N. occidentalis. At the same time, we found that all six CPs when expressed in PVX vector showed similar VSR activity and produced similar symptoms in N. occidentalis, despite their differences in amino acids. CONCLUSIONS Different ASPV isolates induced different symptoms in N. occidentalis, however, ASPV CP variants expressed in PVX vector showed the same symptoms in N. occidentalis plants. Also, we showed that ASPV CP variants has the same level of VSR activity, but they have different abilities to aggregate in N. benthamiana.
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Affiliation(s)
- Xiaofang Ma
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Blvd. de l’Université, Sherbrooke, QC J1K 2R1 Canada
- Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Plant Protection, Nanjing, 210014 China
| | - Ni Hong
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Blvd. de l’Université, Sherbrooke, QC J1K 2R1 Canada
| | - Yijun Zhou
- Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Plant Protection, Nanjing, 210014 China
| | - Guoping Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070 People’s Republic of China
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20
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Aguilar E, del Toro FJ, Brosseau C, Moffett P, Canto T, Tenllado F. Cell death triggered by the P25 protein in Potato virus X-associated synergisms results from endoplasmic reticulum stress in Nicotiana benthamiana. MOLECULAR PLANT PATHOLOGY 2019; 20:194-210. [PMID: 30192053 PMCID: PMC6637867 DOI: 10.1111/mpp.12748] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The synergistic interaction of Potato virus X (PVX) with a number of potyviruses results in systemic necrosis in Nicotiana spp. Previous investigations have indicated that the viral suppressor of RNA silencing (VSR) protein P25 of PVX triggers systemic necrosis in PVX-associated synergisms in a threshold-dependent manner. However, little is still known about the cellular processes that lead to this necrosis, and whether the VSR activity of P25 is involved in its elicitation. Here, we show that transient expression of P25 in the presence of VSRs from different viruses, including the helper component-proteinase (HC-Pro) of potyviruses, induces endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), which ultimately lead to ER collapse. However, the host RNA silencing pathway was dispensable for the elicitation of cell death by P25. Confocal microscopy studies in leaf patches co-expressing P25 and HC-Pro showed dramatic alterations in ER membrane structures, which correlated with the up-regulation of bZIP60 and several ER-resident chaperones, including the ER luminal binding protein (BiP). Overexpression of BiP alleviated the cell death induced by the potexviral P25 protein when expressed together with VSRs derived from different viruses. Conversely, silencing of the UPR master regulator, bZIP60, led to an increase in cell death elicited by the P25/HC-Pro combination as well as by PVX-associated synergism. In addition to its role as a negative regulator of P25-induced cell death, UPR partially restricted PVX infection. Thus, systemic necrosis caused by PVX-associated synergistic infections is probably the effect of an unmitigated ER stress following the overaccumulation of a viral protein, P25, with ER remodelling activity.
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Affiliation(s)
- Emmanuel Aguilar
- Departamento de Biotecnología Microbiana y de PlantasCentro de Investigaciones Biológicas, CSICMadrid28040Spain
| | - Francisco J. del Toro
- Departamento de Biotecnología Microbiana y de PlantasCentro de Investigaciones Biológicas, CSICMadrid28040Spain
| | - Chantal Brosseau
- Centre SÈVE, Département de BiologieUniversité de SherbrookeSherbrookeQCJ1K 2R1Canada
| | - Peter Moffett
- Centre SÈVE, Département de BiologieUniversité de SherbrookeSherbrookeQCJ1K 2R1Canada
| | - Tomás Canto
- Departamento de Biotecnología Microbiana y de PlantasCentro de Investigaciones Biológicas, CSICMadrid28040Spain
| | - Francisco Tenllado
- Departamento de Biotecnología Microbiana y de PlantasCentro de Investigaciones Biológicas, CSICMadrid28040Spain
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21
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Islam W, Naveed H, Zaynab M, Huang Z, Chen HYH. Plant defense against virus diseases; growth hormones in highlights. PLANT SIGNALING & BEHAVIOR 2019; 14:1596719. [PMID: 30957658 PMCID: PMC6546145 DOI: 10.1080/15592324.2019.1596719] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/12/2019] [Indexed: 05/20/2023]
Abstract
Phytohormones are critical in various aspects of plant biology such as growth regulations and defense strategies against pathogens. Plant-virus interactions retard plant growth through rapid alterations in phytohormones and their signaling pathways. Recent research findings show evidence of how viruses impact upon modulation of various phytohormones affecting plant growth regulations. The opinion is getting stronger that virus-mediated phytohormone disruption and alteration weaken plant defense strategies through enhanced replication and systemic spread of viral particles. These hormones regulate plant-virus interactions in various ways that may involve antagonism and cross talk to modulate small RNA (sRNA) systems. The article aims to highlight the recent research findings elaborating the impact of viruses upon manipulation of phytohormones and virus biology.
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Affiliation(s)
- Waqar Islam
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
| | - Hassan Naveed
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Madiha Zaynab
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhiqun Huang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
- Zhiqun Huang Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China
| | - Han Y. H. Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
- Faculty of Natural Resources Management, Lakehead University, Ontario, Canada
- CONTACT Han Y. H. Chen Faculty of Natural Resources Management, Lakehead University, Ontario Canada
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Paudel DB, Sanfaçon H. Exploring the Diversity of Mechanisms Associated With Plant Tolerance to Virus Infection. FRONTIERS IN PLANT SCIENCE 2018; 9:1575. [PMID: 30450108 PMCID: PMC6224807 DOI: 10.3389/fpls.2018.01575] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/09/2018] [Indexed: 05/17/2023]
Abstract
Tolerance is defined as an interaction in which viruses accumulate to some degree without causing significant loss of vigor or fitness to their hosts. Tolerance can be described as a stable equilibrium between the virus and its host, an interaction in which each partner not only accommodate trade-offs for survival but also receive some benefits (e.g., protection of the plant against super-infection by virulent viruses; virus invasion of meristem tissues allowing vertical transmission). This equilibrium, which would be associated with little selective pressure for the emergence of severe viral strains, is common in wild ecosystems and has important implications for the management of viral diseases in the field. Plant viruses are obligatory intracellular parasites that divert the host cellular machinery to complete their infection cycle. Highjacking/modification of plant factors can affect plant vigor and fitness. In addition, the toxic effects of viral proteins and the deployment of plant defense responses contribute to the induction of symptoms ranging in severity from tissue discoloration to malformation or tissue necrosis. The impact of viral infection is also influenced by the virulence of the specific virus strain (or strains for mixed infections), the host genotype and environmental conditions. Although plant resistance mechanisms that restrict virus accumulation or movement have received much attention, molecular mechanisms associated with tolerance are less well-understood. We review the experimental evidence that supports the concept that tolerance can be achieved by reaching the proper balance between plant defense responses and virus counter-defenses. We also discuss plant translation repression mechanisms, plant protein degradation or modification pathways and viral self-attenuation strategies that regulate the accumulation or activity of viral proteins to mitigate their impact on the host. Finally, we discuss current progress and future opportunities toward the application of various tolerance mechanisms in the field.
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Affiliation(s)
- Dinesh Babu Paudel
- Department of Botany, The University of British Columbia, Vancouver, BC, Canada
| | - Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada
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Sun Q, Li YY, Wang Y, Zhao HH, Zhao TY, Zhang ZY, Li DW, Yu JL, Wang XB, Zhang YL, Han CG. Brassica yellows virus P0 protein impairs the antiviral activity of NbRAF2 in Nicotiana benthamiana. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:3127-3139. [PMID: 29659986 PMCID: PMC5972614 DOI: 10.1093/jxb/ery131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 03/24/2018] [Indexed: 05/29/2023]
Abstract
In interactions between poleroviruses and their hosts, few cellular proteins have been identified that directly interact with the multifunctional virus P0 protein. To help explore the functions of P0, we identified a Brassica yellows virus genotype A (BrYV-A) P0BrA-interacting protein from Nicotiana benthamiana, Rubisco assembly factor 2 (NbRAF2), which localizes in the nucleus, cell periphery, chloroplasts, and stromules. We found that its C-terminal domain (amino acids 183-211) is required for self-interaction. A split ubiquitin membrane-bound yeast two-hybrid system and co-immunoprecipitation assays showed that NbRAF2 interacted with P0BrA, and co-localized in the nucleus and at the cell periphery. Interestingly, the nuclear pool of NbRAF2 decreased in the presence of P0BrA and during BrYV-A infection, and the P0BrA-mediated reduction of nuclear NbRAF2 required dual localization of NbRAF2 in the chloroplasts and nucleus. Tobacco rattle virus-based virus-induced gene silencing of NbRAF2 promoted BrYV-A infection in N. benthamiana, and the overexpression of nuclear NbRAF2 inhibited BrYV-A accumulation. Potato leafroll virus P0PL also interacted with NbRAF2 and decreased its nuclear accumulation, indicating that NbRAF2 may be a common target of poleroviruses. These results suggest that nuclear NbRAF2 possesses antiviral activity against BrYV-A infection, and that BrYV-A P0BrA interacts with NbRAF2 and alters its localization pattern to facilitate virus infection.
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Affiliation(s)
- Qian Sun
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Yuan-Yuan Li
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Ying Wang
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Hang-Hai Zhao
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Tian-Yu Zhao
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Zong-Ying Zhang
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
| | - Da-Wei Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Jia-Lin Yu
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Yong-Liang Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, P. R., China
| | - Cheng-Gui Han
- State Key Laboratory for Agro-biotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, P. R. China
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Miyashita Y, Atsumi G, Nakahara KS. Trade-Offs for Viruses in Overcoming Innate Immunities in Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:595-8. [PMID: 27294885 DOI: 10.1094/mpmi-05-16-0103-cr] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Plants recognize viral infection via an immune receptor, i.e., nucleotide-binding site (NB)-leucine-rich repeat (LRR) proteins. Another immune receptor, receptor-like kinase proteins, which share an LRR domain with NB-LRRs, perceive conserved molecules of pathogens called pathogen- or microbe-associated molecular patterns, but NB-LRRs generally perceive particular viral proteins. As viruses can evolve more rapidly than the host immune system, how do plant immune systems, which rely on the perception of proteins, remain effective? Viral adaptive evolution may be controlled by penalties that result from mutations in viral proteins that are perceived by NB-LRRs. Our recent studies in pea (Pisum sativum) suggest a penalty of increased susceptibility to another immune system. When a viral protein mutates to evade one immune system, the virus with the mutated protein becomes more susceptible to another. Such antagonistic pleiotropy of a viral protein by two independent plant immune systems may have precedents. Plants may rely on pairs of immune systems to constrain adaptive evolution by viruses and thereby maintain durable antiviral immunity.
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Affiliation(s)
- Yuri Miyashita
- 1 Pathogen-Plant Interactions Group, Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; and
| | - Go Atsumi
- 2 National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan
| | - Kenji S Nakahara
- 1 Pathogen-Plant Interactions Group, Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; and
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25
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Wieczorek P, Obrępalska-Stęplowska A. The N-terminal fragment of the tomato torrado virus RNA1-encoded polyprotein induces a hypersensitive response (HR)-like reaction in Nicotiana benthamiana. Arch Virol 2016; 161:1849-58. [PMID: 27072852 PMCID: PMC4908173 DOI: 10.1007/s00705-016-2841-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/19/2016] [Indexed: 11/30/2022]
Abstract
The hypersensitive response (HR) is a defence reaction observed during incompatible plant-pathogen interactions in plants infected with a wide range of fungi, bacteria and viruses. Here, we show that an N-terminal polyprotein fragment encoded by tomato torrado virus RNA1, located between the first ATG codon and the protease cofactor (ProCo) motif, induces an HR-like reaction in Nicotiana benthamiana. Agrobacterium tumefaciens-mediated transient expression of the first 105 amino acids (the calculated molecular weight of the fragment was ca. 11.33 kDa, hereafter refered to as the 11K domain) from ToTV RNA1 induced an HR-like phenotype in infiltrated leaves. To investigate whether the 11K domain could influence the virulence and pathogenicity of a recombinant virus, we created a potato virus X (PVX) with the 11K coding sequence inserted under a duplicated coat protein promoter. We found that 11K substantially increased the virulence of the recombinant virus. Disease phenotype induced in N. benthamiana by PVX-11K was characterized by strong local and systemic necrosis. This was not observed when the 11K domain was expressed from PVX in an antisense orientation. Further analyses revealed that the 11K domain could not suppress posttranscriptional gene silencing (PTGS) of green fluorescent protein (GFP) in the N. benthamiana 16c line. In silico analysis of the predicted secondary structure of the 11K domain indicated the presence of two putative helices that are highly conserved in tomato-infecting representatives of the genus Torradovirus.
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Affiliation(s)
- Przemysław Wieczorek
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, 20 Władysława Węgorka St, 60-318, Poznan, Poland
| | - Aleksandra Obrępalska-Stęplowska
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, 20 Władysława Węgorka St, 60-318, Poznan, Poland.
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26
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Miyashita Y, Atsumi G, Nakahara KS. Trade-Offs for Viruses in Overcoming Innate Immunities in Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 2016:1-4. [PMID: 27838953 DOI: 10.1094/mpmi-05-16-0103-cr.2016.1.test] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Plants recognize viral infection via an immune receptor, i.e., nucleotide-binding site (NB)-leucine-rich repeat (LRR) proteins. Another immune receptor, receptor-like kinase proteins, which share an LRR domain with NB-LRRs, perceive conserved molecules of pathogens called pathogen- or microbe-associated molecular patterns, but NB-LRRs generally perceive particular viral proteins. As viruses can evolve more rapidly than the host immune system, how do plant immune systems, which rely on the perception of proteins, remain effective? Viral adaptive evolution may be controlled by penalties that result from mutations in viral proteins that are perceived by NB-LRRs. Our recent studies in pea (Pisum sativum) suggest a penalty of increased susceptibility to another immune system. When a viral protein mutates to evade one immune system, the virus with the mutated protein becomes more susceptible to another. Such antagonistic pleiotropy of a viral protein by two independent plant immune systems may have precedents. Plants may rely on pairs of immune systems to constrain adaptive evolution by viruses and thereby maintain durable antiviral immunity. [Formula: see text] Copyright © 2016 The Author(s). This is an open access article distributed under the CC BY-NC 4.0 International license .
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Affiliation(s)
- Yuri Miyashita
- 1 Pathogen-Plant Interactions Group, Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; and
| | - Go Atsumi
- 2 National Institute of Advanced Industrial Science and Technology, Sapporo 062-8517, Japan
| | - Kenji S Nakahara
- 1 Pathogen-Plant Interactions Group, Plant Breeding Science, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan; and
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27
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Kubota K, Ng JCK. Lettuce chlorosis virus P23 Suppresses RNA Silencing and Induces Local Necrosis with Increased Severity at Raised Temperatures. PHYTOPATHOLOGY 2016; 106:653-62. [PMID: 26828232 DOI: 10.1094/phyto-09-15-0219-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
RNA silencing functions as an antivirus defense strategy in plants, one that plant viruses counter by producing viral suppressors of RNA silencing (VSRs). VSRs have been identified in three members of the genus Crinivirus but they do not all share identical suppression mechanisms. Here, we used Agrobacterium co-infiltration assays to investigate the suppressor activity of proteins encoded by Lettuce chlorosis virus (LCV). Of 7 LCV proteins (1b, P23, HSP70 homolog, P60, CP, CPm, and P27) tested for the suppression of silencing of green fluorescent protein (GFP) expression in wild-type Nicotiana benthamiana plants, only P23 suppressed the onset of local silencing. Small-interfering (si)RNA accumulation was reduced in leaves co-infiltrated with P23, suggesting that P23 inhibited the accumulation or enhanced the degradation of siRNA. P23 also inhibited the cell-to-cell and systemic movement of RNA silencing in GFP-expressing transgenic N. benthamiana plants. Expression of P23 via agroinfiltration of N. benthamiana leaves induced local necrosis that increased in severity at elevated temperatures, a novelty given that a direct temperature effect on necrosis severity has not been reported for the other crinivirus VSRs. These results further affirm the sophistication of crinivirus VSRs in mediating the evasion of host's antiviral defenses and in symptom modulation.
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Affiliation(s)
- Kenji Kubota
- First author: NARO Agricultural Research Center, Kannondai, Tsukuba, Ibaraki 305-8666, Japan, and Department of Plant Pathology and Microbiology, University of California, Riverside 92521; second author: Department of Plant Pathology and Microbiology, University of California, Riverside 92521
| | - James C K Ng
- First author: NARO Agricultural Research Center, Kannondai, Tsukuba, Ibaraki 305-8666, Japan, and Department of Plant Pathology and Microbiology, University of California, Riverside 92521; second author: Department of Plant Pathology and Microbiology, University of California, Riverside 92521
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28
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Chen S, Jiang G, Wu J, Liu Y, Qian Y, Zhou X. Characterization of a Novel Polerovirus Infecting Maize in China. Viruses 2016; 8:E120. [PMID: 27136578 PMCID: PMC4885075 DOI: 10.3390/v8050120] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 04/20/2016] [Accepted: 04/22/2016] [Indexed: 12/17/2022] Open
Abstract
A novel virus, tentatively named Maize Yellow Mosaic Virus (MaYMV), was identified from the field-grown maize plants showing yellow mosaic symptoms on the leaves collected from the Yunnan Province of China by the deep sequencing of small RNAs. The complete 5642 nucleotide (nt)-long genome of the MaYMV shared the highest nucleotide sequence identity (73%) to Maize Yellow Dwarf Virus-RMV. Sequence comparisons and phylogenetic analyses suggested that MaYMV represents a new member of the genus Polerovirus in the family Luteoviridae. Furthermore, the P0 protein encoded by MaYMV was demonstrated to inhibit both local and systemic RNA silencing by co-infiltration assays using transgenic Nicotiana benthamiana line 16c carrying the GFP reporter gene, which further supported the identification of a new polerovirus. The biologically-active cDNA clone of MaYMV was generated by inserting the full-length cDNA of MaYMV into the binary vector pCB301. RT-PCR and Northern blot analyses showed that this clone was systemically infectious upon agro-inoculation into N. benthamiana. Subsequently, 13 different isolates of MaYMV from field-grown maize plants in different geographical locations of Yunnan and Guizhou provinces of China were sequenced. Analyses of their molecular variation indicate that the 3' half of P3-P5 read-through protein coding region was the most variable, whereas the coat protein- (CP-) and movement protein- (MP-)coding regions were the most conserved.
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Affiliation(s)
- Sha Chen
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Guangzhuang Jiang
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Jianxiang Wu
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Yong Liu
- Key Laboratory of Pest Management of Horticultural Crop of Hunan Province, Hunan Plant Protection Institute, Hunan Academy of Agricultural Science, Changsha 410125, China.
| | - Yajuan Qian
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Xueping Zhou
- Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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29
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Aguilar E, Allende L, Del Toro FJ, Chung BN, Canto T, Tenllado F. Effects of Elevated CO₂and Temperature on Pathogenicity Determinants and Virulence of Potato virus X/Potyvirus-Associated Synergism. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:1364-1373. [PMID: 26422405 DOI: 10.1094/mpmi-08-15-0178-r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Infections of plants by multiple viruses are common in nature and may result in synergisms in pathologies. Several environmental factors influence plant-virus interactions and act on virulence and host defense responses. Mixed viral infections may be more frequent under environmental conditions associated with global warming. Here, we address how changes in the two main parameters behind global warming, carbon dioxide concentrations ([CO₂]) and temperature, may affect virulence of Potato virus X (PVX)/potyvirus-associated synergism compared with single infections in Nicotiana benthamiana. Elevated [CO₂] resulted in attenuated virulence of single infection by PVX, which correlated with a lower accumulation of virus. In contrast, virulence of PVX/potyvirus-associated synergism was maintained at elevated [CO₂]. On the other hand, elevated temperature decreased markedly both virulence and virus titers in the synergistic infection. We also show that the HR-like response elicited by transient coexpression of PVX P25 together with the potyviral helper component-proteinase protein was significantly enhanced by elevated temperature, whereas it was reduced by elevated [CO₂]. Both proteins are main pathogenicity determinants in PVX-associated synergisms. These findings indicate that, under environmental conditions associated with global warming, virulence of PVX/potyvirus-associated synergisms is expected to vary relative to single infections and, thus, may have pathological consequences in the future.
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Affiliation(s)
- Emmanuel Aguilar
- 1 Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; and
| | - Lucía Allende
- 1 Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; and
| | - Francisco J Del Toro
- 1 Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; and
| | - Bong-Nam Chung
- 2 National Institute of Horticultural & Herbal Science. Agricultural Research Center for Climate Change. 281, Ayeon-ro, Jeju, 690-150, Jeju Island, Republic of Korea
| | - Tomás Canto
- 1 Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; and
| | - Francisco Tenllado
- 1 Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040, Madrid, Spain; and
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30
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Ali S, Magne M, Chen S, Obradovic N, Jamshaid L, Wang X, Bélair G, Moffett P. Analysis of Globodera rostochiensis effectors reveals conserved functions of SPRYSEC proteins in suppressing and eliciting plant immune responses. FRONTIERS IN PLANT SCIENCE 2015; 6:623. [PMID: 26322064 PMCID: PMC4532164 DOI: 10.3389/fpls.2015.00623] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/27/2015] [Indexed: 05/08/2023]
Abstract
Potato cyst nematodes (PCNs), including Globodera rostochiensis (Woll.), are important pests of potato. Plant parasitic nematodes produce multiple effector proteins, secreted from their stylets, to successfully infect their hosts. These include proteins delivered to the apoplast and to the host cytoplasm. A number of effectors from G. rostochiensis predicted to be delivered to the host cytoplasm have been identified, including several belonging to the secreted SPRY domain (SPRYSEC) family. SPRYSEC proteins are unique to members of the genus Globodera and have been implicated in both the induction and the repression of host defense responses. We have tested the properties of six different G. rostochiensis SPRYSEC proteins by expressing them in Nicotiana benthamiana and N. tabacum. We have found that all SPRYSEC proteins tested are able to suppress defense responses induced by NB-LRR proteins as well as cell death induced by elicitors, suggesting that defense repression is a common characteristic of members of this effector protein family. At the same time, GrSPRYSEC-15 elicited a defense responses in N. tabacum, which was found to be resistant to a virus expressing GrSPRYSEC-15. These results suggest that SPRYSEC proteins may possess characteristics that allow them to be recognized by the plant immune system.
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Affiliation(s)
- Shawkat Ali
- Département de Biologie, Université de SherbrookeSherbrooke, QC, Canada
- Horticulture R & D Centre, Agriculture and Agri-Food CanadaSt-Jean-sur-Richelieu, QC, Canada
- Division of Biological and Environmental Sciences and Engineering, Center for Desert Agriculture, King Abdullah University of Science and TechnologyThuwal, Saudi Arabia
| | - Maxime Magne
- Département de Biologie, Université de SherbrookeSherbrooke, QC, Canada
| | - Shiyan Chen
- School of Integrative Plant Science, Cornell UniversityIthaca, NY, USA
| | - Natasa Obradovic
- Département de Biologie, Université de SherbrookeSherbrooke, QC, Canada
| | - Lubna Jamshaid
- Département de Biologie, Université de SherbrookeSherbrooke, QC, Canada
| | - Xiaohong Wang
- School of Integrative Plant Science, Cornell UniversityIthaca, NY, USA
- US Department of Agriculture, Robert W. Holley Center for Agriculture and Health, Agricultural Research ServiceIthaca, NY, USA
| | - Guy Bélair
- Horticulture R & D Centre, Agriculture and Agri-Food CanadaSt-Jean-sur-Richelieu, QC, Canada
| | - Peter Moffett
- Département de Biologie, Université de SherbrookeSherbrooke, QC, Canada
- *Correspondence: Peter Moffett, Faculté des Sciences, 2500 Boulevard de l'Université, Sherbrooke, QC J1K 2R1, Canada
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