1
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Lukhovitskaya N, Brown K, Hua L, Pate AE, Carr JP, Firth AE. A novel ilarvirus protein CP-RT is expressed via stop codon readthrough and suppresses RDR6-dependent RNA silencing. PLoS Pathog 2024; 20:e1012034. [PMID: 38814986 PMCID: PMC11166343 DOI: 10.1371/journal.ppat.1012034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 06/11/2024] [Accepted: 05/03/2024] [Indexed: 06/01/2024] Open
Abstract
Ilarviruses are a relatively understudied but important group of plant RNA viruses that includes a number of crop pathogens. Their genomes comprise three RNA segments encoding two replicase subunits, movement protein, coat protein (CP), and (in some ilarvirus subgroups) a protein that suppresses RNA silencing. Here we report that, in many ilarviruses, RNA3 encodes an additional protein (termed CP-RT) as a result of ribosomal readthrough of the CP stop codon into a short downstream readthrough (RT) ORF. Using asparagus virus 2 as a model, we find that CP-RT is expressed in planta where it functions as a weak suppressor of RNA silencing. CP-RT expression is essential for persistent systemic infection in leaves and shoot apical meristem. CP-RT function is dependent on a putative zinc-finger motif within RT. Replacing the asparagus virus 2 RT with the RT of an ilarvirus from a different subgroup restored the ability to establish persistent infection. These findings open up a new avenue for research on ilarvirus silencing suppression, persistent meristem invasion and vertical transmission.
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Affiliation(s)
- Nina Lukhovitskaya
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Katherine Brown
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Lei Hua
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Adrienne E. Pate
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Andrew E. Firth
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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2
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Wu J, Zhang Y, Li F, Zhang X, Ye J, Wei T, Li Z, Tao X, Cui F, Wang X, Zhang L, Yan F, Li S, Liu Y, Li D, Zhou X, Li Y. Plant virology in the 21st century in China: Recent advances and future directions. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:579-622. [PMID: 37924266 DOI: 10.1111/jipb.13580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 11/02/2023] [Indexed: 11/06/2023]
Abstract
Plant viruses are a group of intracellular pathogens that persistently threaten global food security. Significant advances in plant virology have been achieved by Chinese scientists over the last 20 years, including basic research and technologies for preventing and controlling plant viral diseases. Here, we review these milestones and advances, including the identification of new crop-infecting viruses, dissection of pathogenic mechanisms of multiple viruses, examination of multilayered interactions among viruses, their host plants, and virus-transmitting arthropod vectors, and in-depth interrogation of plant-encoded resistance and susceptibility determinants. Notably, various plant virus-based vectors have also been successfully developed for gene function studies and target gene expression in plants. We also recommend future plant virology studies in China.
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Affiliation(s)
- Jianguo Wu
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Vector-borne Virus Research Center, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yongliang Zhang
- State Key Laboratory of Plant Environmental Resilience and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiaoming Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Ye
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Taiyun Wei
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Vector-borne Virus Research Center, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenghe Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Xiaorong Tao
- Department of Plant Pathology, The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China
| | - Feng Cui
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xianbing Wang
- State Key Laboratory of Plant Environmental Resilience and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Lili Zhang
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Fei Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Virology, Ningbo University, Ningbo, 315211, China
| | - Shifang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Dawei Li
- State Key Laboratory of Plant Environmental Resilience and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yi Li
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Vector-borne Virus Research Center, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
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3
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Hoffmann G, López-González S, Mahboubi A, Hanson J, Hafrén A. Cauliflower mosaic virus protein P6 is a multivalent node for RNA granule proteins and interferes with stress granule responses during plant infection. THE PLANT CELL 2023; 35:3363-3382. [PMID: 37040611 PMCID: PMC10473198 DOI: 10.1093/plcell/koad101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/06/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
Biomolecular condensation is a multipurpose cellular process that viruses use ubiquitously during their multiplication. Cauliflower mosaic virus replication complexes are condensates that differ from those of most viruses, as they are nonmembranous assemblies that consist of RNA and protein, mainly the viral protein P6. Although these viral factories (VFs) were described half a century ago, with many observations that followed since, functional details of the condensation process and the properties and relevance of VFs have remained enigmatic. Here, we studied these issues in Arabidopsis thaliana and Nicotiana benthamiana. We observed a large dynamic mobility range of host proteins within VFs, while the viral matrix protein P6 is immobile, as it represents the central node of these condensates. We identified the stress granule (SG) nucleating factors G3BP7 and UBP1 family members as components of VFs. Similarly, as SG components localize to VFs during infection, ectopic P6 localizes to SGs and reduces their assembly after stress. Intriguingly, it appears that soluble rather than condensed P6 suppresses SG formation and mediates other essential P6 functions, suggesting that the increased condensation over the infection time-course may accompany a progressive shift in selected P6 functions. Together, this study highlights VFs as dynamic condensates and P6 as a complex modulator of SG responses.
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Affiliation(s)
- Gesa Hoffmann
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Silvia López-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
| | - Amir Mahboubi
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90736 Umeå, Sweden
| | - Johannes Hanson
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, 90736 Umeå, Sweden
| | - Anders Hafrén
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
- Linnean Center for Plant Biology, 75007 Uppsala, Sweden
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4
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Ham BK, Wang X, Toscano-Morales R, Lin J, Lucas WJ. Plasmodesmal endoplasmic reticulum proteins regulate intercellular trafficking of cucumber mosaic virus in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:4401-4414. [PMID: 37210666 PMCID: PMC10838158 DOI: 10.1093/jxb/erad190] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023]
Abstract
Plasmodesmata (PD) are plasma membrane-lined cytoplasmic nanochannels that mediate cell-to-cell communication across the cell wall. A range of proteins are embedded in the PD plasma membrane and endoplasmic reticulum (ER), and function in regulating PD-mediated symplasmic trafficking. However, knowledge of the nature and function of the ER-embedded proteins in the intercellular movement of non-cell-autonomous proteins is limited. Here, we report the functional characterization of two ER luminal proteins, AtBiP1/2, and two ER integral membrane proteins, AtERdj2A/B, which are located within the PD. These PD proteins were identified as interacting proteins with cucumber mosaic virus (CMV) movement protein (MP) in co-immunoprecipitation studies using an Arabidopsis-derived plasmodesmal-enriched cell wall protein preparation (PECP). The AtBiP1/2 PD location was confirmed by TEM-based immunolocalization, and their AtBiP1/2 signal peptides (SPs) function in PD targeting. In vitro/in vivo pull-down assays revealed the association between AtBiP1/2 and CMV MP, mediated by AtERdj2A, through the formation of an AtBiP1/2-AtERdj2-CMV MP complex within PD. The role of this complex in CMV infection was established, as systemic infection was retarded in bip1/bip2w and erdj2b mutants. Our findings provide a model for a mechanism by which the CMV MP mediates cell-to-cell trafficking of its viral ribonucleoprotein complex.
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Affiliation(s)
- Byung-Kook Ham
- Global Institute for Food Security (GIFS), University of Saskatchewan, 421 Downey Rd, Saskatoon, SK S7N 4L8, Canada
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Xiaohua Wang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Roberto Toscano-Morales
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Jinxing Lin
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - William J Lucas
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
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5
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Tong X, Zhao JJ, Feng YL, Zou JZ, Ye J, Liu J, Han C, Li D, Wang XB. A selective autophagy receptor VISP1 induces symptom recovery by targeting viral silencing suppressors. Nat Commun 2023; 14:3852. [PMID: 37385991 PMCID: PMC10310818 DOI: 10.1038/s41467-023-39426-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 06/09/2023] [Indexed: 07/01/2023] Open
Abstract
Selective autophagy is a double-edged sword in antiviral immunity and regulated by various autophagy receptors. However, it remains unclear how to balance the opposite roles by one autophagy receptor. We previously identified a virus-induced small peptide called VISP1 as a selective autophagy receptor that facilitates virus infections by targeting components of antiviral RNA silencing. However, we show here that VISP1 can also inhibit virus infections by mediating autophagic degradation of viral suppressors of RNA silencing (VSRs). VISP1 targets the cucumber mosaic virus (CMV) 2b protein for degradation and attenuates its suppression activity on RNA silencing. Knockout and overexpression of VISP1 exhibit compromised and enhanced resistance against late infection of CMV, respectively. Consequently, VISP1 induces symptom recovery from CMV infection by triggering 2b turnover. VISP1 also targets the C2/AC2 VSRs of two geminiviruses and enhances antiviral immunity. Together, VISP1 induces symptom recovery from severe infections of plant viruses through controlling VSR accumulation.
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Affiliation(s)
- Xin Tong
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
- College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Jia-Jia Zhao
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Ya-Lan Feng
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Jing-Ze Zou
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Jian Ye
- State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Junfeng Liu
- College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Chenggui Han
- College of Plant Protection, China Agricultural University, 100193, Beijing, China
| | - Dawei Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Xian-Bing Wang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, 100193, Beijing, China.
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6
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Kwon MJ, Kwon SJ, Kim MH, Choi B, Byun HS, Kwak HR, Seo JK. Visual tracking of viral infection dynamics reveals the synergistic interactions between cucumber mosaic virus and broad bean wilt virus 2. Sci Rep 2023; 13:7261. [PMID: 37142679 PMCID: PMC10160061 DOI: 10.1038/s41598-023-34553-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 05/03/2023] [Indexed: 05/06/2023] Open
Abstract
Cucumber mosaic virus (CMV) is one of the most prevalent plant viruses in the world, and causes severe damage to various crops. CMV has been studied as a model RNA virus to better understand viral replication, gene functions, evolution, virion structure, and pathogenicity. However, CMV infection and movement dynamics remain unexplored due to the lack of a stable recombinant virus tagged with a reporter gene. In this study, we generated a CMV infectious cDNA construct tagged with a variant of the flavin-binding LOV photoreceptor (iLOV). The iLOV gene was stably maintained in the CMV genome after more than four weeks of three serial passages between plants. Using the iLOV-tagged recombinant CMV, we visualized CMV infection and movement dynamics in living plants in a time course manner. We also examined whether CMV infection dynamics is influenced by co-infection with broad bean wilt virus 2 (BBWV2). Our results revealed that no spatial interference occurred between CMV and BBWV2. Specifically, BBWV2 facilitated the cell-to-cell movement of CMV in the upper young leaves. In addition, the BBWV2 accumulation level increased after co-infection with CMV.
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Affiliation(s)
- Min-Jun Kwon
- Department of International Agricultural Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea
| | - Sun-Jung Kwon
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea
| | - Myung-Hwi Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Republic of Korea
| | - Boram Choi
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea
| | - Hee-Seong Byun
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Hae-Ryun Kwak
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, 55365, Republic of Korea
| | - Jang-Kyun Seo
- Department of International Agricultural Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea.
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang, 25354, Republic of Korea.
- Department of Agricultural Biotechnology, Seoul National University, Seoul, 08826, Republic of Korea.
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7
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Malavika M, Prakash V, Chakraborty S. Recovery from virus infection: plant's armory in action. PLANTA 2023; 257:103. [PMID: 37115475 DOI: 10.1007/s00425-023-04137-9] [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: 12/09/2022] [Accepted: 04/14/2023] [Indexed: 05/26/2023]
Abstract
MAIN CONCLUSION This review focuses on different factors involved in promoting symptom recovery in plants post-virus infection such as epigenetics, transcriptional reprogramming, phytohormones with an emphasis on RNA silencing as well as role of abiotic factors such as temperature on symptom recovery. Plants utilize several different strategies to defend themselves in the battle against invading viruses. Most of the viral proteins interact with plant proteins and interfere with molecular dynamics in a cell which eventually results in symptom development. This initial symptom development is countered by the plant utilizing various factors including the plant's adaptive immunity to develop a virus tolerant state. Infected plants can specifically target and impede the transcription of viral genes as well as degrade the viral transcripts to restrict their proliferation by the production of small-interfering RNA (siRNA) generated from the viral nucleic acid, known as virus-derived siRNA (vsiRNA). To further escalate the degradation of viral nucleic acid, secondary siRNAs are generated. The production of virus-activated siRNA (vasiRNA) from the host genome causes differential regulation of the host transcriptome which plays a major role in establishing a virus tolerant state within the infected plant. The systemic action of vsiRNAs, vasiRNA, and secondary siRNAs with the help of defense hormones like salicylic acid can curb viral proliferation, and thus the newly emerged leaves develop fewer symptoms, maintaining a state of tolerance.
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Affiliation(s)
- M Malavika
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ved Prakash
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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8
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Zhang C, Wang D, Li W, Zhang B, Abdel-Fattah Ouf GM, Su X, Li J. The coat protein p25 from maize chlorotic mottle virus involved in symptom development and systemic movement of tobacco mosaic virus hybrids. Front Microbiol 2022; 13:951479. [PMID: 35992724 PMCID: PMC9389212 DOI: 10.3389/fmicb.2022.951479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Viral coat protein (CP) has numerous critical functions in plant infection, but little is known about p25, the CP of maize chlorotic mottle virus (MCMV; Machlomovirus), which causes severe yield losses in maize worldwide. Here, we investigated the roles of p25 in pathogenicity and systemic movement, as well as potential interactions with host plants, using a hybrid tobacco mosaic virus (TMV)-based expression system. Highly conserved protein p25 is predicted to contain a membrane-anchored nuclear localization signal (NLS) sequence and an extracellular sequence. In transgenic Nicotiana benthamiana plants containing the movement protein (MP) of TMV (TMV-MP), p25 induced severe symptoms, including dwarf and foliar necrosis, and was detected in inoculated and non-inoculated leaves. After the deletion of NLS from nuclear-located p25, the protein was found throughout the host cell, and plant stunting and starch granule deformity were reduced. Systemic movement and pathogenicity were significantly impaired when the C-terminal regions of p25 were absent. Using virus-induced gene silencing (VIGS), the transcript level of heat shock protein HSP90 was distinctly lower in host plants in association with the absence of leaf necrosis induced by TMV-p25. Our results revealed crucial roles for MCMV p25 in viral pathogenicity, long-distance movement, and interactions with N. benthamiana.
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Affiliation(s)
- Chao Zhang
- State Key Laboratory of North China Crop Improvement and Regulation, College of Life Sciences, Hebei Agricultural University, Baoding, China
| | - Di Wang
- Center for Advanced Measurement Science, National Institute of Metrology, Beijing, China
| | - Weimin Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baolong Zhang
- Excellence and Innovation Center, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Gamal M. Abdel-Fattah Ouf
- Department of Botany and Applied Microbiology, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Xiaofeng Su
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun Li
- State Key Laboratory of North China Crop Improvement and Regulation, College of Life Sciences, Hebei Agricultural University, Baoding, China
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9
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Ding ZH, Gao Q, Tong X, Xu WY, Ma L, Zhang ZJ, Wang Y, Wang XB. MAPKs trigger antiviral immunity by directly phosphorylating a rhabdovirus nucleoprotein in plants and insect vectors. THE PLANT CELL 2022; 34:3110-3127. [PMID: 35567529 PMCID: PMC9338794 DOI: 10.1093/plcell/koac143] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/22/2022] [Indexed: 05/16/2023]
Abstract
Signaling by the evolutionarily conserved mitogen-activated protein kinase or extracellular signal-regulated kinase (MAPK/ERK) plays critical roles in converting extracellular stimuli into immune responses. However, whether MAPK/ERK signaling induces virus immunity by directly phosphorylating viral effectors remains largely unknown. Barley yellow striate mosaic virus (BYSMV) is an economically important plant cytorhabdovirus that is transmitted by the small brown planthopper (SBPH, Laodelphax striatellus) in a propagative manner. Here, we found that the barley (Hordeum vulgare) MAPK MPK3 (HvMPK3) and the planthopper ERK (LsERK) proteins interact with the BYSMV nucleoprotein (N) and directly phosphorylate N protein primarily on serine 290. The overexpression of HvMPK3 inhibited BYSMV infection, whereas barley plants treated with the MAPK pathway inhibitor U0126 displayed greater susceptibility to BYSMV. Moreover, knockdown of LsERK promoted virus infection in SBPHs. A phosphomimetic mutant of the N Ser290 (S290D) completely abolished virus infection because of impaired self-interaction of BYSMV N and formation of unstable N-RNA complexes. Altogether, our results demonstrate that the conserved MAPK and ERK directly phosphorylate the viral nucleoprotein to trigger immunity against cross-kingdom infection of BYSMV in host plants and its insect vectors.
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Affiliation(s)
- Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qiang Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Xin Tong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Lulu Ma
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Ying Wang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
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10
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Wu Z, Ma G, Zhu H, Chen M, Huang M, Xie X, Li X. Plant Viral Coat Proteins as Biochemical Targets for Antiviral Compounds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:8892-8900. [PMID: 35830295 DOI: 10.1021/acs.jafc.2c02888] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Coat proteins (CPs) of RNA plant viruses play a pivotal role in virus particle assembly, vector transmission, host identification, RNA replication, and intracellular and intercellular movement. Numerous compounds targeting CPs have been designed, synthesized, and screened for their antiviral activities. This review is intended to fill a knowledge gap where a comprehensive summary is needed for antiviral agent discovery based on plant viral CPs. In this review, major achievements are summarized with emphasis on plant viral CPs as biochemical targets and action mechanisms of antiviral agents. This review hopefully provides new insights and references for the further development of new safe and effective antiviral pesticides.
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Affiliation(s)
- Zilin Wu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Guangming Ma
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Hengmin Zhu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Meiqing Chen
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Min Huang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xin Xie
- College of Agriculture, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
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11
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Shukla A, Hoffmann G, Kushwaha NK, López-González S, Hofius D, Hafrén A. Salicylic acid and the viral virulence factor 2b regulate the divergent roles of autophagy during cucumber mosaic virus infection. Autophagy 2022; 18:1450-1462. [PMID: 34740306 PMCID: PMC9225522 DOI: 10.1080/15548627.2021.1987674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Macroautophagy/autophagy is a conserved intracellular degradation pathway that has recently emerged as an integral part of plant responses to virus infection. The known mechanisms of autophagy range from the selective degradation of viral components to a more general attenuation of disease symptoms. In addition, several viruses are able to manipulate the autophagy machinery and counteract autophagy-dependent resistance. Despite these findings, the complex interplay of autophagy activities, viral pathogenicity factors, and host defense pathways in disease development remains poorly understood. In the current study, we analyzed the interaction between autophagy and cucumber mosaic virus (CMV) in Arabidopsis thaliana. We show that autophagy is induced during CMV infection and promotes the turnover of the major virulence protein and RNA silencing suppressor 2b. Intriguingly, autophagy induction is mediated by salicylic acid (SA) and dampened by the CMV virulence factor 2b. In accordance with 2b degradation, we found that autophagy provides resistance against CMV by reducing viral RNA accumulation in an RNA silencing-dependent manner. Moreover, autophagy and RNA silencing attenuate while SA promotes CMV disease symptoms, and epistasis analysis suggests that autophagy-dependent disease and resistance are uncoupled. We propose that autophagy counteracts CMV virulence via both 2b degradation and reduced SA-responses, thereby increasing plant fitness with the viral trade-off arising from increased RNA silencing-mediated resistance.
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Affiliation(s)
- Aayushi Shukla
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
| | - Gesa Hoffmann
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
| | - Nirbhay Kumar Kushwaha
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
| | - Silvia López-González
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
| | - Daniel Hofius
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
| | - Anders Hafrén
- Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Box 7080, 75007Uppsala, Sweden
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12
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Zou JZ, Liu DS, Tong X, Zhang XP, Wang XB. RNA In Situ Hybridization of Detecting Cucumber Mosaic Virus in Shoots of Nicotiana benthamiana Plants. Methods Mol Biol 2022; 2400:283-296. [PMID: 34905211 DOI: 10.1007/978-1-0716-1835-6_27] [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] [Indexed: 06/14/2023]
Abstract
RNA in situ hybridization, a histological technique derived from Southern blotting and northern blotting, has been an important approach in biology studies for many years. In the studies of virus-plant interactions, RNA in situ hybridization provides a direct visualization of viral RNA in host plants. Here, we provide a detailed protocol for viral RNA in situ hybridization that has been successfully used to detect Cucumber mosaic virus genome (CMV) RNAs in shoots of N. benthamiana plants.
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Affiliation(s)
- Jing-Ze Zou
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - De-Shui Liu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xin Tong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiao-Peng Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.
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13
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Pasin F, Daròs JA, Tzanetakis IE. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6534904. [PMID: 35195244 PMCID: PMC9249622 DOI: 10.1093/femsre/fuac011] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022] Open
Abstract
Potyviridae, the largest family of known RNA viruses (realm Riboviria), belongs to the picorna-like supergroup and has important agricultural and ecological impacts. Potyvirid genomes are translated into polyproteins, which are in turn hydrolyzed to release mature products. Recent sequencing efforts revealed an unprecedented number of potyvirids with a rich variability in gene content and genomic layouts. Here, we review the heterogeneity of non-core modules that expand the structural and functional diversity of the potyvirid proteomes. We provide a family-wide classification of P1 proteinases into the functional Types A and B, and discuss pretty interesting sweet potato potyviral ORF (PISPO), putative zinc fingers, and alkylation B (AlkB)—non-core modules found within P1 cistrons. The atypical inosine triphosphate pyrophosphatase (ITPase/HAM1), as well as the pseudo tobacco mosaic virus-like coat protein (TMV-like CP) are discussed alongside homologs of unrelated virus taxa. Family-wide abundance of the multitasking helper component proteinase (HC-pro) is revised. Functional connections between non-core modules are highlighted to support host niche adaptation and immune evasion as main drivers of the Potyviridae evolutionary radiation. Potential biotechnological and synthetic biology applications of potyvirid leader proteinases and non-core modules are finally explored.
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Affiliation(s)
- Fabio Pasin
- Corresponding author: Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), UPV Building 8E, Ingeniero Fausto Elio, 46011 Valencia, Spain. E-mail:
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), 46011 Valencia, Spain
| | - Ioannis E Tzanetakis
- Department of Entomology and Plant Pathology, Division of Agriculture, University of Arkansas System, 72701 Fayetteville, AR, USA
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14
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Clavel M, Lechner E, Incarbone M, Vincent T, Cognat V, Smirnova E, Lecorbeiller M, Brault V, Ziegler-Graff V, Genschik P. Atypical molecular features of RNA silencing against the phloem-restricted polerovirus TuYV. Nucleic Acids Res 2021; 49:11274-11293. [PMID: 34614168 PMCID: PMC8565345 DOI: 10.1093/nar/gkab802] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/25/2021] [Accepted: 10/04/2021] [Indexed: 11/12/2022] Open
Abstract
In plants and some animal lineages, RNA silencing is an efficient and adaptable defense mechanism against viruses. To counter it, viruses encode suppressor proteins that interfere with RNA silencing. Phloem-restricted viruses are spreading at an alarming rate and cause substantial reduction of crop yield, but how they interact with their hosts at the molecular level is still insufficiently understood. Here, we investigate the antiviral response against phloem-restricted turnip yellows virus (TuYV) in the model plant Arabidopsis thaliana. Using a combination of genetics, deep sequencing, and mechanical vasculature enrichment, we show that the main axis of silencing active against TuYV involves 22-nt vsiRNA production by DCL2, and their preferential loading into AGO1. Moreover, we identify vascular secondary siRNA produced from plant transcripts and initiated by DCL2-processed AGO1-loaded vsiRNA. Unexpectedly, and despite the viral encoded VSR P0 previously shown to mediate degradation of AGO proteins, vascular AGO1 undergoes specific post-translational stabilization during TuYV infection. Collectively, our work uncovers the complexity of antiviral RNA silencing against phloem-restricted TuYV and prompts a re-assessment of the role of its suppressor of silencing P0 during genuine infection.
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Affiliation(s)
- Marion Clavel
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Esther Lechner
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Marco Incarbone
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Timothée Vincent
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Valerie Cognat
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Ekaterina Smirnova
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Maxime Lecorbeiller
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | | | - Véronique Ziegler-Graff
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Pascal Genschik
- Institut de Biologie Moléculaire des Plantes, CNRS, Université de Strasbourg, Strasbourg, France
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15
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Kumari R, Kumar S, Leibman D, Abebie B, Shnaider Y, Ding S, Gal‐On A. Cucumber RDR1s and cucumber mosaic virus suppressor protein 2b association directs host defence in cucumber plants. MOLECULAR PLANT PATHOLOGY 2021; 22:1317-1331. [PMID: 34355485 PMCID: PMC8518566 DOI: 10.1111/mpp.13112] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/03/2021] [Accepted: 07/05/2021] [Indexed: 05/27/2023]
Abstract
RNA-dependent RNA polymerases (RDRs) regulate important aspects of plant development and resistance to pathogens. The role of RDRs in virus resistance has been demonstrated using siRNA signal amplification and through the methylation of viral genomes. Cucumber (Cucumis sativus) has four RDR1 genes that are differentially induced during virus infection: CsRDR1a, CsRDR1b, and duplicated CsRDR1c1/c2. The mode of action of CsRDR1s during viral infection is unknown. Transient expression of the cucumber mosaic virus (CMV)-2b protein (the viral suppressor of RNA silencing) in cucumber protoplasts induced the expression of CsRDR1c, but not of CsRDR1a/1b. Results from the yeast two-hybrid system showed that CsRDR1 proteins interacted with CMV-2b and this was confirmed by bimolecular fluorescence complementation assays. In protoplasts, CsRDR1s localized in the cytoplasm as punctate spots. Colocalization experiments revealed that CsRDR1s and CMV-2b were uniformly dispersed throughout the cytoplasm, suggesting that CsRDR1s are redistributed as a result of interactions. Transient overexpression of individual CsRDR1a/1b genes in protoplasts reduced CMV accumulation, indicating their antiviral role. However, overexpression of CsRDR1c in protoplasts resulted in relatively higher accumulation of CMV and CMVΔ2b. In single cells, CsRDR1c enhances viral replication, leading to CMV accumulation and blocking secondary siRNA amplification of CsRDR1c by CMV-2b protein. This suggests that CMV-2b acts as both a transcription factor that induces CsRDR1c (controlling virus accumulation) and a suppressor of CsRDR1c activity.
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Affiliation(s)
- Reenu Kumari
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
- College of Horticulture and ForestryDr YS Parmar University of Horticulture and ForestryMandiIndia
| | - Surender Kumar
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
- Plant Virology Lab, Biotechnology DivisionCSIR‐Institute of Himalayan Bioresource TechnologyPalampurIndia
| | - Diana Leibman
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
| | - Bekele Abebie
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
| | - Yulia Shnaider
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
| | - Shou‐Wei Ding
- Department of Plant Pathology and Microbiology & Institute for Integrative Genome BiologyUniversity of CaliforniaRiversideCaliforniaUSA
| | - Amit Gal‐On
- Department of Plant Pathology and Weed ResearchAgricultural Research OrganizationRishon LeZionIsrael
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16
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Bradamante G, Mittelsten Scheid O, Incarbone M. Under siege: virus control in plant meristems and progeny. THE PLANT CELL 2021; 33:2523-2537. [PMID: 34015140 PMCID: PMC8408453 DOI: 10.1093/plcell/koab140] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/14/2021] [Indexed: 05/29/2023]
Abstract
In the arms race between plants and viruses, two frontiers have been utilized for decades to combat viral infections in agriculture. First, many pathogenic viruses are excluded from plant meristems, which allows the regeneration of virus-free plant material by tissue culture. Second, vertical transmission of viruses to the host progeny is often inefficient, thereby reducing the danger of viral transmission through seeds. Numerous reports point to the existence of tightly linked meristematic and transgenerational antiviral barriers that remain poorly understood. In this review, we summarize the current understanding of the molecular mechanisms that exclude viruses from plant stem cells and progeny. We also discuss the evidence connecting viral invasion of meristematic cells and the ability of plants to recover from acute infections. Research spanning decades performed on a variety of virus/host combinations has made clear that, beside morphological barriers, RNA interference (RNAi) plays a crucial role in preventing-or allowing-meristem invasion and vertical transmission. How a virus interacts with plant RNAi pathways in the meristem has profound effects on its symptomatology, persistence, replication rates, and, ultimately, entry into the host progeny.
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Affiliation(s)
- Gabriele Bradamante
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Marco Incarbone
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
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17
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Ghosh D, M M, Chakraborty S. Impact of viral silencing suppressors on plant viral synergism: a global agro-economic concern. Appl Microbiol Biotechnol 2021; 105:6301-6313. [PMID: 34423406 DOI: 10.1007/s00253-021-11483-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/27/2022]
Abstract
Plant viruses are known for their devastating impact on global agriculture. These intracellular biotrophic pathogens can infect a wide variety of plant hosts all over the world. The synergistic association of plant viruses makes the situation more alarming. It usually promotes the replication, movement, and transmission of either or both the coexisting synergistic viral partners. Although plants elicit a robust antiviral immune reaction, including gene silencing, to limit these infamous invaders, viruses counter it by encoding viral suppressors of RNA silencing (VSRs). Growing evidence also suggests that VSRs play a driving role in mediating the plant viral synergism. This review briefly discusses the evil impacts of mixed infections, especially synergism, and then comprehensively describes the emerging roles of VSRs in mediating the synergistic association of plant viruses. KEY POINTS: • Synergistic associations of plant viruses have devastating impacts on global agriculture. • Viral suppressors of RNA silencing (VSRs) play key roles in driving plant viral synergism.
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Affiliation(s)
- Dibyendu Ghosh
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Malavika M
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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18
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Nigam D. Genomic Variation and Diversification in Begomovirus Genome in Implication to Host and Vector Adaptation. PLANTS (BASEL, SWITZERLAND) 2021; 10:1706. [PMID: 34451752 PMCID: PMC8398267 DOI: 10.3390/plants10081706] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 01/02/2023]
Abstract
Begomoviruses (family Geminiviridae, genus Begomovirus) are DNA viruses transmitted in a circulative, persistent manner by the whitefly Bemisia tabaci (Gennadius). As revealed by their wide host range (more than 420 plant species), worldwide distribution, and effective vector transmission, begomoviruses are highly adaptive. Still, the genetic factors that facilitate their adaptation to a diverse array of hosts and vectors remain poorly understood. Mutations in the virus genome may confer a selective advantage for essential functions, such as transmission, replication, evading host responses, and movement within the host. Therefore, genetic variation is vital to virus evolution and, in response to selection pressure, is demonstrated as the emergence of new strains and species adapted to diverse hosts or with unique pathogenicity. The combination of variation and selection forms a genetic imprint on the genome. This review focuses on factors that contribute to the evolution of Begomovirus and their global spread, for which an unforeseen diversity and dispersal has been recognized and continues to expand.
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Affiliation(s)
- Deepti Nigam
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
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19
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Tong X, Liu S, Zou J, Zhao J, Zhu F, Chai L, Wang Y, Han C, Wang X. A small peptide inhibits siRNA amplification in plants by mediating autophagic degradation of SGS3/RDR6 bodies. EMBO J 2021; 40:e108050. [PMID: 34155657 PMCID: PMC8327956 DOI: 10.15252/embj.2021108050] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 05/20/2021] [Accepted: 05/27/2021] [Indexed: 12/13/2022] Open
Abstract
Selective autophagy mediates specific degradation of unwanted cytoplasmic components to maintain cellular homeostasis. The suppressor of gene silencing 3 (SGS3) and RNA-dependent RNA polymerase 6 (RDR6)-formed bodies (SGS3/RDR6 bodies) are essential for siRNA amplification in planta. However, whether autophagy receptors regulate selective turnover of SGS3/RDR6 bodies is unknown. By analyzing the transcriptomic response to virus infection in Arabidopsis, we identified a virus-induced small peptide 1 (VISP1) composed of 71 amino acids, which harbor a ubiquitin-interacting motif that mediates interaction with autophagy-related protein 8. Overexpression of VISP1 induced selective autophagy and compromised antiviral immunity by inhibiting SGS3/RDR6-dependent viral siRNA amplification, whereas visp1 mutants exhibited opposite effects. Biochemistry assays demonstrate that VISP1 interacted with SGS3 and mediated autophagic degradation of SGS3/RDR6 bodies. Further analyses revealed that overexpression of VISP1, mimicking the sgs3 mutant, impaired biogenesis of endogenous trans-acting siRNAs and up-regulated their targets. Collectively, we propose that VISP1 is a small peptide receptor functioning in the crosstalk between selective autophagy and RNA silencing.
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Affiliation(s)
- Xin Tong
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Song‐Yu Liu
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Jing‐Ze Zou
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Jia‐Jia Zhao
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Fei‐Fan Zhu
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Long‐Xiang Chai
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Ying Wang
- College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Chenggui Han
- College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Xian‐Bing Wang
- State Key Laboratory of Agro‐BiotechnologyCollege of Biological SciencesChina Agricultural UniversityBeijingChina
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20
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Wang X, Ma J, Jin X, Yue N, Gao P, Mai KKK, Wang XB, Li D, Kang BH, Zhang Y. Three-dimensional reconstruction and comparison of vacuolar membranes in response to viral infection. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:353-364. [PMID: 33085164 DOI: 10.1111/jipb.13027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/20/2020] [Indexed: 06/11/2023]
Abstract
The vacuole is a unique plant organelle that plays an important role in maintaining cellular homeostasis under various environmental stress conditions. However, the effects of biotic stress on vacuole structure has not been examined using three-dimensional (3D) visualization. Here, we performed 3D electron tomography to compare the ultrastructural changes in the vacuole during infection with different viruses. The 3D models revealed that vacuoles are remodeled in cells infected with cucumber mosaic virus (CMV) or tobacco necrosis virus A Chinese isolate (TNV-AC ), resulting in the formation of spherules at the periphery of the vacuole. These spherules contain neck-like channels that connect their interior with the cytosol. Confocal microscopy of CMV replication proteins 1a and 2a and TNV-AC auxiliary replication protein p23 showed that all of these proteins localize to the tonoplast. Electron microscopy revealed that the expression of these replication proteins alone is sufficient to induce spherule formation on the tonoplast, suggesting that these proteins play prominent roles in inducing vacuolar membrane remodeling. This is the first report of the 3D structures of viral replication factories built on the tonoplasts. These findings contribute to our understanding of vacuole biogenesis under normal conditions and during assembly of plant (+) RNA virus replication complexes.
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Affiliation(s)
- Xueting Wang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Juncai Ma
- State Key Laboratory of Agro-Biotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, 999077, China
| | - Xuejiao Jin
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Ning Yue
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Peng Gao
- State Key Laboratory of Agro-Biotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, 999077, China
| | - Keith Ka Ki Mai
- State Key Laboratory of Agro-Biotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, 999077, 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, 100193, China
| | - Dawei Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Byung-Ho Kang
- State Key Laboratory of Agro-Biotechnology, School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, 999077, China
| | - Yongliang Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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21
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Li M, Li C, Jiang K, Li K, Zhang J, Sun M, Wu G, Qing L. Characterization of Pathogenicity-Associated V2 Protein of Tobacco Curly Shoot Virus. Int J Mol Sci 2021; 22:E923. [PMID: 33477652 PMCID: PMC7831499 DOI: 10.3390/ijms22020923] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 11/17/2022] Open
Abstract
V2 proteins encoded by some whitefly-transmitted geminiviruses were reported to be functionally important proteins. However, the functions of the V2 protein of tobacco curly shoot virus (TbCSV), a monopartite begomovirus that causes leaf curl disease on tomato and tobacco in China, remains to be characterized. In our report, an Agrobacterium infiltration-mediated transient expression assay indicated that TbCSV V2 can suppress local and systemic RNA silencing and the deletion analyses demonstrated that the amino acid region 1-92 of V2, including the five predicted α-helices, are required for local RNA silencing suppression. Site-directed substitutions showed that the conserved basic and ring-structured amino acids in TbCSV V2 are critical for its suppressor activity. Potato virus X-mediated heteroexpression of TbCSV V2 in Nicotiana benthamiana induced hypersensitive response-like (HR-like) cell death and systemic necrosis in a manner independent of V2's suppressor activity. Furthermore, TbCSV infectious clone mutant with untranslated V2 protein (TbCSV∆V2) could not induce visual symptoms, and coinfection with betasatellite (TbCSB) could obviously elevate the viral accumulation and symptom development. Interestingly, symptom recovery occurred at 15 days postinoculation (dpi) and onward in TbCSV∆V2/TbCSB-inoculated plants. The presented work contributes to understanding the RNA silencing suppression activity of TbCSV V2 and extends our knowledge of the multifunctional role of begomovirus-encoded V2 proteins during viral infections.
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Affiliation(s)
- Mingjun Li
- Correspondence: (M.L.); (L.Q.); Tel.: +86-023-68250517 (L.Q.)
| | | | | | | | | | | | | | - Ling Qing
- Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing 400716, China; (C.L.); (K.J.); (K.L.); (J.Z.); (M.S.); (G.W.)
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22
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Ramesh SV, Yogindran S, Gnanasekaran P, Chakraborty S, Winter S, Pappu HR. Virus and Viroid-Derived Small RNAs as Modulators of Host Gene Expression: Molecular Insights Into Pathogenesis. Front Microbiol 2021; 11:614231. [PMID: 33584579 PMCID: PMC7874048 DOI: 10.3389/fmicb.2020.614231] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/19/2020] [Indexed: 02/01/2023] Open
Abstract
Virus-derived siRNAs (vsiRNAs) generated by the host RNA silencing mechanism are effectors of plant’s defense response and act by targeting the viral RNA and DNA in post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) pathways, respectively. Contrarily, viral suppressors of RNA silencing (VSRs) compromise the host RNA silencing pathways and also cause disease-associated symptoms. In this backdrop, reports describing the modulation of plant gene(s) expression by vsiRNAs via sequence complementarity between viral small RNAs (sRNAs) and host mRNAs have emerged. In some cases, silencing of host mRNAs by vsiRNAs has been implicated to cause characteristic symptoms of the viral diseases. Similarly, viroid infection results in generation of sRNAs, originating from viroid genomic RNAs, that potentially target host mRNAs causing typical disease-associated symptoms. Pathogen-derived sRNAs have been demonstrated to have the propensity to target wide range of genes including host defense-related genes, genes involved in flowering and reproductive pathways. Recent evidence indicates that vsiRNAs inhibit host RNA silencing to promote viral infection by acting as decoy sRNAs. Nevertheless, it remains unclear if the silencing of host transcripts by viral genome-derived sRNAs are inadvertent effects due to fortuitous pairing between vsiRNA and host mRNA or the result of genuine counter-defense strategy employed by viruses to enhance its survival inside the plant cell. In this review, we analyze the instances of such cross reaction between pathogen-derived vsiRNAs and host mRNAs and discuss the molecular insights regarding the process of pathogenesis.
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Affiliation(s)
- S V Ramesh
- ICAR-Central Plantation Crops Research Institute, Kasaragod, India
| | - Sneha Yogindran
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Prabu Gnanasekaran
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | | | - Stephan Winter
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany
| | - Hanu R Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
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Sanan-Mishra N, Abdul Kader Jailani A, Mandal B, Mukherjee SK. Secondary siRNAs in Plants: Biosynthesis, Various Functions, and Applications in Virology. FRONTIERS IN PLANT SCIENCE 2021; 12:610283. [PMID: 33737942 PMCID: PMC7960677 DOI: 10.3389/fpls.2021.610283] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/18/2021] [Indexed: 05/13/2023]
Abstract
The major components of RNA silencing include both transitive and systemic small RNAs, which are technically called secondary sRNAs. Double-stranded RNAs trigger systemic silencing pathways to negatively regulate gene expression. The secondary siRNAs generated as a result of transitive silencing also play a substantial role in gene silencing especially in antiviral defense. In this review, we first describe the discovery and pathways of transitivity with emphasis on RNA-dependent RNA polymerases followed by description on the short range and systemic spread of silencing. We also provide an in-depth view on the various size classes of secondary siRNAs and their different roles in RNA silencing including their categorization based on their biogenesis. The other regulatory roles of secondary siRNAs in transgene silencing, virus-induced gene silencing, transitivity, and trans-species transfer have also been detailed. The possible implications and applications of systemic silencing and the different gene silencing tools developed are also described. The details on mobility and roles of secondary siRNAs derived from viral genome in plant defense against the respective viruses are presented. This entails the description of other compatible plant-virus interactions and the corresponding small RNAs that determine recovery from disease symptoms, exclusion of viruses from shoot meristems, and natural resistance. The last section presents an overview on the usefulness of RNA silencing for management of viral infections in crop plants.
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Affiliation(s)
- Neeti Sanan-Mishra
- Plant RNAi Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - A. Abdul Kader Jailani
- Plant RNAi Biology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
- Advanced Center for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, India
| | - Bikash Mandal
- Advanced Center for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, India
| | - Sunil K. Mukherjee
- Advanced Center for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, India
- *Correspondence: Sunil K. Mukherjee,
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24
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Guo H, Ge P, Tong J, Zhang Y, Peng X, Zhao Z, Ge F, Sun Y. Elevated Carbon Dioxide Levels Decreases Cucumber Mosaic Virus Accumulation in Correlation with Greater Accumulation of rgs-CaM, an Inhibitor of a Viral Suppressor of RNAi. PLANTS (BASEL, SWITZERLAND) 2020; 10:E59. [PMID: 33383811 PMCID: PMC7824600 DOI: 10.3390/plants10010059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/23/2020] [Accepted: 12/25/2020] [Indexed: 11/16/2022]
Abstract
Plant viruses cause a range of plant diseases symptoms that are often responsible for significant crop production losses and the severity and spread of the symptoms may be affected by climate change. While the increase in anthropogenic activities has caused a critical problem of increased CO2 levels in the atmosphere, these elevated CO2 levels have been reported to reduce virus disease severity in some plant species. In such instances, it is not clear if the plant defense mechanisms are being enhanced or virus-mediated mechanisms to overcome plant resistance are being defeated. Additionally, a few studies have been attempted in this area to determine if reduced disease is the norm or the exception under enhanced CO2 levels. In the present study, the effects of elevated CO2 levels (750 ppm vs. 390 ppm) on RNAi-mediated resistance of Nicotiana tabacum against the cucumber mosaic virus (CMV), and the activity of viral suppressor of RNAi (VSR) 2b protein of CMV were evaluated. On the one hand, our results showed that elevated CO2 decreased the transcription of dicer-like protein 2 (DCL2), DCL4, and argonaut 1 (AGO1) genes with functions related to RNAi-mediated resistance when infected by CMV, which is contradictory with the decreased CMV copy numbers under elevated CO2. On the other hand, we found that elevated CO2 increased the calcium concentration and expression of the calcium-binding protein rgs-CaM in tobacco plants when infected by CMV, which directly weakened the function of 2b protein, the VSR of CMV, and therefore decreased the infection efficiency of the virus and suppressed the severity of CMV in tobacco plants under elevated CO2. This study provides molecular insights into the ecological implications underlying the development of prevention strategies against plant virus infection in the context of climate change.
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Affiliation(s)
- Huijuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
| | - Panpan Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
| | - Jiahui Tong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Yanjing Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
| | - Xinhong Peng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, China
| | - Zihua Zhao
- Department of Entomology, College of Plant Protection, China Agricultural University, Beijing 100193, China;
| | - Feng Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
| | - Yucheng Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; (H.G.); (P.G.); (J.T.); (Y.Z.); (X.P.)
- CAS Center for Excellence in Biotic Interactions, Chinese Academy of Sciences, Beijing 100049, China
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25
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Watt LG, Crawshaw S, Rhee SJ, Murphy AM, Canto T, Carr JP. The cucumber mosaic virus 1a protein regulates interactions between the 2b protein and ARGONAUTE 1 while maintaining the silencing suppressor activity of the 2b protein. PLoS Pathog 2020; 16:e1009125. [PMID: 33270799 PMCID: PMC7738167 DOI: 10.1371/journal.ppat.1009125] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 12/15/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022] Open
Abstract
The cucumber mosaic virus (CMV) 2b viral suppressor of RNA silencing (VSR) is a potent counter-defense and pathogenicity factor that inhibits antiviral silencing by titration of short double-stranded RNAs. It also disrupts microRNA-mediated regulation of host gene expression by binding ARGONAUTE 1 (AGO1). But in Arabidopsis thaliana complete inhibition of AGO1 is counterproductive to CMV since this triggers another layer of antiviral silencing mediated by AGO2, de-represses strong resistance against aphids (the insect vectors of CMV), and exacerbates symptoms. Using confocal laser scanning microscopy, bimolecular fluorescence complementation, and co-immunoprecipitation assays we found that the CMV 1a protein, a component of the viral replicase complex, regulates the 2b-AGO1 interaction. By binding 2b protein molecules and sequestering them in P-bodies, the 1a protein limits the proportion of 2b protein molecules available to bind AGO1, which ameliorates 2b-induced disease symptoms, and moderates induction of resistance to CMV and to its aphid vector. However, the 1a protein-2b protein interaction does not inhibit the ability of the 2b protein to inhibit silencing of reporter gene expression in agroinfiltration assays. The interaction between the CMV 1a and 2b proteins represents a novel regulatory system in which specific functions of a VSR are selectively modulated by another viral protein. The finding also provides a mechanism that explains how CMV, and possibly other viruses, modulates symptom induction and manipulates host-vector interactions.
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Affiliation(s)
- Lewis G. Watt
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Sam Crawshaw
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Sun-Ju Rhee
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Alex M. Murphy
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Tomás Canto
- Department of Microbial and Plant Biotechnology, Center for Biological Research, Madrid, Spain
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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26
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Chai LX, Dong K, Liu SY, Zhang Z, Zhang XP, Tong X, Zhu FF, Zou JZ, Wang XB. A putative nuclear copper chaperone promotes plant immunity in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6684-6696. [PMID: 32865553 PMCID: PMC7586746 DOI: 10.1093/jxb/eraa401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 08/26/2020] [Indexed: 05/08/2023]
Abstract
Copper is essential for many metabolic processes but must be sequestrated by copper chaperones. It is well known that plant copper chaperones regulate various physiological processes. However, the functions of copper chaperones in the plant nucleus remain largely unknown. Here, we identified a putative copper chaperone induced by pathogens (CCP) in Arabidopsis thaliana. CCP harbors a classical MXCXXC copper-binding site (CBS) at its N-terminus and a nuclear localization signal (NLS) at its C-terminus. CCP mainly formed nuclear speckles in the plant nucleus, which requires the NLS and CBS domains. Overexpression of CCP induced PR1 expression and enhanced resistance against Pseudomonas syringae pv. tomato DC3000 compared with Col-0 plants. Conversely, two CRISPR/Cas9-mediated ccp mutants were impaired in plant immunity. Further biochemical analyses revealed that CCP interacted with the transcription factor TGA2 in vivo and in vitro. Moreover, CCP recruits TGA2 to the PR1 promoter sequences in vivo, which induces defense gene expression and plant immunity. Collectively, our results have identified a putative nuclear copper chaperone required for plant immunity and provided evidence for a potential function of copper in the salicylic pathway.
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Affiliation(s)
- Long-Xiang Chai
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Kai Dong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Song-Yu Liu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiao-Peng Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xin Tong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Fei-Fan Zhu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jing-Ze Zou
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
- Correspondence:
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27
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Pasin F, Shan H, García B, Müller M, San León D, Ludman M, Fresno DH, Fátyol K, Munné-Bosch S, Rodrigo G, García JA. Abscisic Acid Connects Phytohormone Signaling with RNA Metabolic Pathways and Promotes an Antiviral Response that Is Evaded by a Self-Controlled RNA Virus. PLANT COMMUNICATIONS 2020; 1:100099. [PMID: 32984814 PMCID: PMC7518510 DOI: 10.1016/j.xplc.2020.100099] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 05/13/2023]
Abstract
A complex network of cellular receptors, RNA targeting pathways, and small-molecule signaling provides robust plant immunity and tolerance to viruses. To maximize their fitness, viruses must evolve control mechanisms to balance host immune evasion and plant-damaging effects. The genus Potyvirus comprises plant viruses characterized by RNA genomes that encode large polyproteins led by the P1 protease. A P1 autoinhibitory domain controls polyprotein processing, the release of a downstream functional RNA-silencing suppressor, and viral replication. Here, we show that P1Pro, a plum pox virus clone that lacks the P1 autoinhibitory domain, triggers complex reprogramming of the host transcriptome and high levels of abscisic acid (ABA) accumulation. A meta-analysis highlighted ABA connections with host pathways known to control RNA stability, turnover, maturation, and translation. Transcriptomic changes triggered by P1Pro infection or ABA showed similarities in host RNA abundance and diversity. Genetic and hormone treatment assays showed that ABA promotes plant resistance to potyviral infection. Finally, quantitative mathematical modeling of viral replication in the presence of defense pathways supported self-control of polyprotein processing kinetics as a viral mechanism that attenuates the magnitude of the host antiviral response. Overall, our findings indicate that ABA is an active player in plant antiviral immunity, which is nonetheless evaded by a self-controlled RNA virus.
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Affiliation(s)
- Fabio Pasin
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
- Agricultural Biotechnology Research Center, Academia Sinica, 11529 Taipei, Taiwan
| | - Hongying Shan
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Beatriz García
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Maren Müller
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - David San León
- Centro Nacional de Biotecnología (CNB-CSIC), 28049 Madrid, Spain
| | - Márta Ludman
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, 2100 Gödöllő, Hungary
| | - David H. Fresno
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - Károly Fátyol
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, 2100 Gödöllő, Hungary
| | - Sergi Munné-Bosch
- Departamento de Biología Evolutiva, Ecología y Ciencias Ambientales, Facultad de Biología, Universidad de Barcelona, 08028 Barcelona, Spain
| | - Guillermo Rodrigo
- Institute for Integrative Systems Biology (I2SysBio), CSIC-University of Valencia, 46980 Paterna, Spain
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28
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Gao Q, Yan T, Zhang ZJ, Liu SY, Fang XD, Gao DM, Yang YZ, Xu WY, Qiao JH, Cao Q, Ding ZH, Wang Y, Yu J, Wang XB. Casein Kinase 1 Regulates Cytorhabdovirus Replication and Transcription by Phosphorylating a Phosphoprotein Serine-Rich Motif. THE PLANT CELL 2020; 32:2878-2897. [PMID: 32641349 PMCID: PMC7474278 DOI: 10.1105/tpc.20.00369] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/24/2020] [Accepted: 07/07/2020] [Indexed: 05/04/2023]
Abstract
Casein kinase 1 (CK1) family members are conserved Ser/Thr protein kinases that regulate important developmental processes in all eukaryotic organisms. However, the functions of CK1 in plant immunity remain largely unknown. Barley yellow striate mosaic virus (BYSMV), a plant cytorhabdovirus, infects cereal crops and is obligately transmitted by the small brown planthopper (SBPH; Laodelphax striatellus). The BYSMV phosphoprotein (P) exists as two forms with different mobilities corresponding to 42 kD (P42) and 44 kD (P44) in SDS-PAGE gels. Mass spectrometric analyses revealed a highly phosphorylated serine-rich (SR) motif at the C-terminal intrinsically disordered region of the P protein. The Ala-substitution mutant (PS5A) in the SR motif stimulated virus replication, whereas the phosphorylation-mimic mutant (PS5D) facilitated virus transcription. Furthermore, PS5A and PS5D associated preferentially with nucleocapsid protein-RNA templates and the large polymerase protein to provide optimal replication and transcription complexes, respectively. Biochemistry assays demonstrated that plant and insect CK1 protein kinases could phosphorylate the SR motif and induce conformational changes from P42 to P44. Moreover, overexpression of CK1 or a dominant-negative mutant impaired the balance between P42 and P44, thereby compromising virus infections. Our results demonstrate that BYSMV recruits the conserved CK1 kinases to achieve its cross-kingdom infection in host plants and insect vectors.
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Affiliation(s)
- Qiang Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Teng Yan
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Song-Yu Liu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiao-Dong Fang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Dong-Min Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yi-Zhou Yang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Ji-Hui Qiao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qing Cao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Ying Wang
- College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Jialin Yu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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29
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Bhardwaj VK, Purohit R. Structural changes induced by substitution of amino acid 129 in the coat protein of Cucumber mosaic virus. Genomics 2020; 112:3729-3738. [DOI: 10.1016/j.ygeno.2020.04.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/01/2020] [Accepted: 04/24/2020] [Indexed: 01/06/2023]
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30
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Sanfaçon H. Modulation of disease severity by plant positive-strand RNA viruses: The complex interplay of multifunctional viral proteins, subviral RNAs and virus-associated RNAs with plant signaling pathways and defense responses. Adv Virus Res 2020; 107:87-131. [PMID: 32711736 DOI: 10.1016/bs.aivir.2020.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Plant viruses induce a range of symptoms of varying intensity, ranging from severe systemic necrosis to mild or asymptomatic infection. Several evolutionary constraints drive virus virulence, including the dependence of viruses on host factors to complete their infection cycle, the requirement to counteract or evade plant antiviral defense responses and the mode of virus transmission. Viruses have developed an array of strategies to modulate disease severity. Accumulating evidence has highlighted not only the multifunctional role that viral proteins play in disrupting or highjacking plant factors, hormone signaling pathways and intracellular organelles, but also the interaction networks between viral proteins, subviral RNAs and/or other viral-associated RNAs that regulate disease severity. This review focusses on positive-strand RNA viruses, which constitute the majority of characterized plant viruses. Using well-characterized viruses with different genome types as examples, recent advances are discussed as well as knowledge gaps and opportunities for further research.
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Affiliation(s)
- Hélène Sanfaçon
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada.
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31
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Miozzi L, Vaira AM, Brilli F, Casarin V, Berti M, Ferrandino A, Nerva L, Accotto GP, Lanfranco L. Arbuscular Mycorrhizal Symbiosis Primes Tolerance to Cucumber Mosaic Virus in Tomato. Viruses 2020; 12:E675. [PMID: 32580438 PMCID: PMC7354615 DOI: 10.3390/v12060675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 01/30/2023] Open
Abstract
Tomato plants can establish symbiotic interactions with arbuscular mycorrhizal fungi (AMF) able to promote plant nutrition and prime systemic plant defenses against pathogens attack; the mechanism involved is known as mycorrhiza-induced resistance (MIR). However, studies on the effect of AMF on viral infection, still limited and not conclusive, indicate that AMF colonization may have a detrimental effect on plant defenses against viruses, so that the term "mycorrhiza-induced susceptibility" (MIS) has been proposed for these cases. To expand the case studies to a not yet tested viral family, that is, Bromoviridae, we investigated the effect of the colonization by the AMF Funneliformis mosseae on cucumber mosaic virus (CMV) infection in tomato by phenotypic, physiological, biochemical, and transcriptional analyses. Our results showed that the establishment of a functional AM symbiosis is able to limit symptoms development. Physiological and transcriptomic data highlighted that AMF mitigates the drastic downregulation of photosynthesis-related genes and the reduction of photosynthetic CO2 assimilation rate caused by CMV infection. In parallel, an increase of salicylic acid level and a modulation of reactive oxygen species (ROS)-related genes, toward a limitation of ROS accumulation, was specifically observed in CMV-infected mycorrhizal plants. Overall, our data indicate that the AM symbiosis influences the development of CMV infection in tomato plants and exerts a priming effect able to enhance tolerance to viral infection.
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Affiliation(s)
- Laura Miozzi
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
| | - Anna Maria Vaira
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
| | - Federico Brilli
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Unit of Sesto Fiorentino (FI), Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy;
| | - Valerio Casarin
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
| | - Mara Berti
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
| | - Alessandra Ferrandino
- Department of Agricultural, Forestry and Food Sciences, University of Torino, Largo Paolo Braccini 2, 10095 Grugliasco (TO), Italy;
| | - Luca Nerva
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
- Council for Agricultural Research and Economics—Research Centre for Viticulture and Enology CREA-VE, Via XXVIII Aprile 26, 31015 Conegliano (TV), Italy
| | - Gian Paolo Accotto
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Torino, Strada delle Cacce 73, 10135 Torino, Italy; (A.M.V.); (V.C.); (M.B.); (L.N.); (G.P.A.)
| | - Luisa Lanfranco
- Department of Life Sciences and Systems Biology, University of Torino, Viale Mattioli 25, 10125 Torino, Italy
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32
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Zhang ZJ, Gao Q, Fang XD, Ding ZH, Gao DM, Xu WY, Cao Q, Qiao JH, Yang YZ, Han C, Wang Y, Yuan X, Li D, Wang XB. CCR4, a RNA decay factor, is hijacked by a plant cytorhabdovirus phosphoprotein to facilitate virus replication. eLife 2020; 9:53753. [PMID: 32207684 PMCID: PMC7105381 DOI: 10.7554/elife.53753] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/21/2020] [Indexed: 12/14/2022] Open
Abstract
Carbon catabolite repression 4 (CCR4) is a conserved mRNA deadenylase regulating posttranscriptional gene expression. However, regulation of CCR4 in virus infections is less understood. Here, we characterized a pro-viral role of CCR4 in replication of a plant cytorhabdovirus, Barley yellow striate mosaic virus (BYSMV). The barley (Hordeum vulgare) CCR4 protein (HvCCR4) was identified to interact with the BYSMV phosphoprotein (P). The BYSMV P protein recruited HvCCR4 from processing bodies (PBs) into viroplasm-like bodies. Overexpression of HvCCR4 promoted BYSMV replication in plants. Conversely, knockdown of the small brown planthopper CCR4 inhibited viral accumulation in the insect vector. Biochemistry experiments revealed that HvCCR4 was recruited into N–RNA complexes by the BYSMV P protein and triggered turnover of N-bound cellular mRNAs, thereby releasing RNA-free N protein to bind viral genomic RNA for optimal viral replication. Our results demonstrate that the co-opted CCR4-mediated RNA decay facilitates cytorhabdovirus replication in plants and insects.
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Affiliation(s)
- Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qiang Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiao-Dong Fang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Dong-Min Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qing Cao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ji-Hui Qiao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yi-Zhou Yang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Chenggui Han
- College of Plant Protection, China Agricultural University, Beijing, China
| | - Ying Wang
- College of Plant Protection, China Agricultural University, Beijing, China
| | - Xuefeng Yuan
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Shandong Province Key Laboratory of Agricultural Microbiology, Tai'an, China
| | - Dawei Li
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
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Xu M, Mazur MJ, Tao X, Kormelink R. Cellular RNA Hubs: Friends and Foes of Plant Viruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:40-54. [PMID: 31415225 DOI: 10.1094/mpmi-06-19-0161-fi] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
RNA granules are dynamic cellular foci that are widely spread in eukaryotic cells and play essential roles in cell growth and development, and immune and stress responses. Different types of granules can be distinguished, each with a specific function and playing a role in, for example, RNA transcription, modification, processing, decay, translation, and arrest. By means of communication and exchange of (shared) components, they form a large regulatory network in cells. Viruses have been reported to interact with one or more of these either cytoplasmic or nuclear granules, and act either proviral, to enable and support viral infection and facilitate viral movement, or antiviral, protecting or clearing hosts from viral infection. This review describes an overview and recent progress on cytoplasmic and nuclear RNA granules and their interplay with virus infection, first in animal systems and as a prelude to the status and current developments on plant viruses, which have been less well studied on this thus far.
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Affiliation(s)
- Min Xu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Magdalena J Mazur
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Xiaorong Tao
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Richard Kormelink
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
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Nemes K, Gellért Á, Bóka K, Vági P, Salánki K. Symptom recovery is affected by Cucumber mosaic virus coat protein phosphorylation. Virology 2019; 536:68-77. [PMID: 31401466 DOI: 10.1016/j.virol.2019.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 08/01/2019] [Accepted: 08/03/2019] [Indexed: 11/29/2022]
Abstract
Cucumber mosaic virus induces specific recovery phenotype, namely cyclic mosaic symptoms on tobacco plants. We provide further evidence that besides the 2b suppressor protein, the coat protein (CP) also has a role in symptom recovery and it is connected to its phosphorylation. We analyzed the impact of the phosphorylated (S148D) and the non-phosphorylated (S148A) state of CP148 Ser on symptom formation, virion stability and the effect of CP and its mutants on 2b-mediated local GFP-silencing. We demonstrated that a single aa change could be responsible for preventing the recovery phenomenon as replacing the phosphorylatable Ser with Ala in the 148aa position abolishing the cyclic phenomenon. CP/S148A mutation equilibrates the accumulation of the virus during the infection both at RNA and protein level in N. tabacum L. cv Xanthi plants. In summary, we determined a regulatory effect of the CMV CP on the self-attenuation mechanism and downregulation of the suppressor effect of the 2b protein.
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Affiliation(s)
- Katalin Nemes
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ákos Gellért
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Károly Bóka
- Department of Plant Anatomy, Eötvös Loránd University, Faculty of Sciences, Budapest, Hungary
| | - Pál Vági
- Department of Plant Anatomy, Eötvös Loránd University, Faculty of Sciences, Budapest, Hungary
| | - Katalin Salánki
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary.
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He L, Wang Q, Gu Z, Liao Q, Palukaitis P, Du Z. A conserved RNA structure is essential for a satellite RNA-mediated inhibition of helper virus accumulation. Nucleic Acids Res 2019; 47:8255-8271. [PMID: 31269212 PMCID: PMC6735963 DOI: 10.1093/nar/gkz564] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/30/2019] [Accepted: 06/20/2019] [Indexed: 12/15/2022] Open
Abstract
As a class of parasitic, non-coding RNAs, satellite RNAs (satRNAs) have to compete with their helper virus for limited amounts of viral and/or host resources for efficient replication, by which they usually reduce viral accumulation and symptom expression. Here, we report a cucumber mosaic virus (CMV)-associated satRNA (sat-T1) that ameliorated CMV-induced symptoms, accompanied with a significant reduction in the accumulation of viral genomic RNAs 1 and 2, which encode components of the viral replicase. Intrans replication assays suggest that the reduced accumulation is the outcome of replication competition. The structural basis of sat-T1 responsible for the inhibition of viral RNA accumulation was determined to be a three-way branched secondary structure that contains two biologically important hairpins. One is indispensable for the helper virus inhibition, and the other engages in formation of a tertiary pseudoknot structure that is essential for sat-T1 survival. The secondary structure containing the pseudoknot is the first RNA element with a biological phenotype experimentally identified in CMV satRNAs, and it is structurally conserved in most CMV satRNAs. Thus, this may be a generic method for CMV satRNAs to inhibit the accumulation of the helper virus via the newly-identified RNA structure.
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Affiliation(s)
- Lu He
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Qian Wang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Zhouhang Gu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Qiansheng Liao
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Nowon-gu, Seoul 01797, Republic of Korea
| | - Zhiyou Du
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
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Gao Q, Xu WY, Yan T, Fang XD, Cao Q, Zhang ZJ, Ding ZH, Wang Y, Wang XB. Rescue of a plant cytorhabdovirus as versatile expression platforms for planthopper and cereal genomic studies. THE NEW PHYTOLOGIST 2019; 223:2120-2133. [PMID: 31059138 DOI: 10.1111/nph.15889] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/28/2019] [Indexed: 05/19/2023]
Abstract
Plant viruses have been used as rapid and cost-effective expression vectors for heterologous protein expression in genomic studies. However, delivering large or multiple foreign proteins in monocots and insect pests is challenging. Here, we recovered a recombinant plant cytorhabdovirus, Barley yellow striate mosaic virus (BYSMV), for use as a versatile expression platform in cereals and the small brown planthopper (SBPH, Laodelphax striatellus) insect vector. We engineered BYSMV vectors to provide versatile expression platforms for simultaneous expression of three foreign proteins in barley plants and SBPHs. Moreover, BYSMV vectors could express the c. 600-amino-acid β-glucuronidase (GUS) protein and a red fluorescent protein stably in systemically infected leaves and roots of cereals, including wheat, barley, foxtail millet, and maize plants. Moreover, we have demonstrated that BYSMV vectors can be used in barley to analyze biological functions of gibberellic acid (GA) biosynthesis genes. In a major technical advance, BYSMV vectors were developed for simultaneous delivery of CRISPR/Cas9 nuclease and single guide RNAs for genomic editing in Nicotiana benthamiana leaves. Taken together, our results provide considerable potential for rapid screening of functional proteins in cereals and planthoppers, and an efficient approach for developing other insect-transmitted negative-strand RNA viruses.
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Affiliation(s)
- Qiang Gao
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Teng Yan
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiao-Dong Fang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Qing Cao
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Ying Wang
- College of Plant Protection, China Agricultural University, Beijing, 100193, 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, 100193, China
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Fang XD, Yan T, Gao Q, Cao Q, Gao DM, Xu WY, Zhang ZJ, Ding ZH, Wang XB. A cytorhabdovirus phosphoprotein forms mobile inclusions trafficked on the actin/ER network for viral RNA synthesis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4049-4062. [PMID: 31020313 PMCID: PMC6685698 DOI: 10.1093/jxb/erz195] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/11/2019] [Indexed: 05/07/2023]
Abstract
As obligate parasites, plant viruses usually hijack host cytoskeletons for replication and movement. Rhabdoviruses are enveloped, negative-stranded RNA viruses that infect vertebrates, invertebrates, and plants, but the mechanisms of intracellular trafficking of plant rhabdovirus proteins are largely unknown. Here, we used Barley yellow striate mosaic virus (BYSMV), a plant cytorhabdovirus, as a model to investigate the effects of the actin cytoskeleton on viral intracellular movement and viral RNA synthesis in a mini-replicon (MR) system. The BYSMV P protein forms mobile inclusion bodies that are trafficked along the actin/endoplasmic reticulum network, and recruit the N and L proteins into viroplasm-like structures. Deletion analysis showed that the N terminal region (aa 43-55) and the remaining region (aa 56-295) of BYSMV P are essential for the mobility and formation of inclusions, respectively. Overexpression of myosin XI-K tails completely abolishes the trafficking activity of P bodies, and is accompanied by a significant reduction of viral MR RNA synthesis. These results suggest that BYSMV P contributes to the formation and trafficking of viroplasm-like structures along the ER/actin network driven by myosin XI-K. Thus, rhabdovirus P appears to be a dynamic hub protein for efficient recruitment of viral proteins, thereby promoting viral RNA synthesis.
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Affiliation(s)
- Xiao-Dong Fang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Teng Yan
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qiang Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qing Cao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Dong-Min Gao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wen-Ya Xu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhen-Jia Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhi-Hang Ding
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
- Correspondence:
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Matić S, Noris E, Contin R, Marian D, Thompson JR. Engineering partial resistance to cucumber mosaic virus in tobacco using intrabodies specific for the viral polymerase. PHYTOCHEMISTRY 2019; 162:99-108. [PMID: 30877900 DOI: 10.1016/j.phytochem.2019.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
A single-chain variable antibody fragment (scFv) library tested against the non-structural NSP5 protein of human rotavirus A was screened by a yeast two-hybrid system against three proteins derived from the RNA-dependent RNA polymerase (RdRp) of cucumber mosaic virus (CMV), with the aim of blocking their function and preventing viral infection once expressed in planta. The constructs tested were (i) '2a' consisting of the full-length 2a gene (839 amino acids, aa), (ii) 'Motifs' covering the conserved RdRp motifs (IV-VII) (132 aa) and (iii) 'GDD' located within the conserved RdRp motif VI (GDD, 22 aa). In yeast two-hybrid (Y2H) selection assays the '2a' and 'Motifs' constructs interacted with 96 and 25 library constructs, respectively, while the 'GDD' construct caused transactivation. Y2H-interacting scFvs were analyzed in vivo for their interaction with the 2a and Motifs proteins in a mammalian transient expression system. Eighteen tobacco lines stably transformed with four selected scFvs were produced and screened for resistance against two different CMV isolates. Different levels of resistance and rate of recovery were observed with CMV of both groups I and II, particularly in lines expressing intrabodies against the full-length 2a protein. This work describes for the first time the use of intrabodies against the RdRp of CMV to obtain plants that reduce infection of a pandemic virus, showing that the selected scFvs can modulate virus infection and induce premature recovery in tobacco plants.
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Affiliation(s)
- Slavica Matić
- Plant Virology Group, ICGEB Biosafety Outstation, Ca'Tron di Roncade (TV), Italy; Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin (TO), Italy
| | - Emanuela Noris
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin (TO), Italy
| | - Roberta Contin
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste (TS), Italy
| | - Daniele Marian
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Turin (TO), Italy
| | - Jeremy R Thompson
- Plant Virology Group, ICGEB Biosafety Outstation, Ca'Tron di Roncade (TV), Italy; Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, USA.
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Yang X, Guo W, Li F, Sunter G, Zhou X. Geminivirus-Associated Betasatellites: Exploiting Chinks in the Antiviral Arsenal of Plants. TRENDS IN PLANT SCIENCE 2019; 24:519-529. [PMID: 31003895 DOI: 10.1016/j.tplants.2019.03.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/21/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Betasatellites are a diverse group of circular single-stranded DNA satellites frequently associated with begomoviruses belonging to the family Geminiviridae. Challenged with a geminivirus-betasatellite infection, plants have employed sophisticated defense mechanisms to protect themselves. Betasatellites, in turn, employ mechanisms to antagonize these plant antiviral pathways. In this review, we focus on the anti-geminiviral immune pathways present both in plants and whiteflies. We also outline the counter-defensive strategies deployed by betasatellites to overcome the host defenses and initiate a successful infection. Finally, we discuss the outcomes of the opposing forces of plant immunity and betasatellite-mediated antagonism in the context of an evolutionary arms race. Understanding of the molecular dialog between plants and betasatellites will likely allow for the development of novel antiviral strategies.
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Affiliation(s)
- Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wei Guo
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Garry Sunter
- Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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40
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Gao D, Wang D, Chen K, Huang M, Xie X, Li X. Activation of biochemical factors in CMV-infected tobacco by ningnanmycin. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 156:116-122. [PMID: 31027570 DOI: 10.1016/j.pestbp.2019.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 01/09/2019] [Accepted: 02/11/2019] [Indexed: 06/09/2023]
Abstract
Cucumber mosaic virus (CMV) is a plant virus with one of the largest host ranges, the widest distribution, and economic importance, and ningnanmycin (NNM) is a commercial antiviral agent. Studies have shown that NNM induces and promotes pathogenesis-related proteins in tobacco mosaic virus-inoculated tobacco. In the present study, the defense enzymes and the biochemical factors of CMV-inoculated tobacco treated with NNM were measured. The biochemical factors of CMV-inoculated tobacco leaves treated with NNM were analyzed. Results showed that the phenylalanine ammonia-lyase, peroxidase, polypheuoloxidase, and superoxide in the CMV-inoculated tobacco leaves treated with NNM were higher than those in non-treated tobacco leaves. Furthermore, NNM activated the oxidation-reduction process, metabolic process, and oxidoreductase activity in the CMV-infected tobacco.
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Affiliation(s)
- Di Gao
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Dongmei Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Kai Chen
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Maoxi Huang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Xin Xie
- College of Agriculture, Guizhou University, Guiyang 550025, PR China.
| | - Xiangyang Li
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China.
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Zhang Z, Tong X, Liu SY, Chai LX, Zhu FF, Zhang XP, Zou JZ, Wang XB. Genetic analysis of a Piezo-like protein suppressing systemic movement of plant viruses in Arabidopsis thaliana. Sci Rep 2019; 9:3187. [PMID: 30816193 PMCID: PMC6395819 DOI: 10.1038/s41598-019-39436-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/24/2019] [Indexed: 01/01/2023] Open
Abstract
As obligate intracellular phytopathogens, plant viruses must take advantage of hosts plasmodesmata and phloem vasculature for their local and long-distance transports to establish systemic infection in plants. In contrast to well-studied virus local transports, molecular mechanisms and related host genes governing virus systemic trafficking are far from being understood. Here, we performed a forward genetic screening to identify Arabidopsis thaliana mutants with enhanced susceptibility to a 2b-deleted mutant of cucumber mosaic virus (CMV-2aT∆2b). We found that an uncharacterized Piezo protein (AtPiezo), an ortholog of animal Piezo proteins with mechanosensitive (MS) cation channel activities, was required for inhibiting systemic infection of CMV-2aT∆2b and turnip mosaic virus tagged a green fluorescent protein (GFP) (TuMV-GFP). AtPiezo is induced by virus infection, especially in the petioles of rosette leaves. Thus, we for the first time demonstrate the biological function of Piezo proteins in plants, which might represent a common antiviral strategy because many monocot and dicot plant species have a single Piezo ortholog.
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Affiliation(s)
- Zhen Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xin Tong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Song-Yu Liu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Long-Xiang Chai
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Fei-Fan Zhu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xiao-Peng Zhang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jing-Ze Zou
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xian-Bing Wang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
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RNA Interference: A Natural Immune System of Plants to Counteract Biotic Stressors. Cells 2019; 8:cells8010038. [PMID: 30634662 PMCID: PMC6356646 DOI: 10.3390/cells8010038] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/01/2019] [Accepted: 01/07/2019] [Indexed: 02/06/2023] Open
Abstract
During plant-pathogen interactions, plants have to defend the living transposable elements from pathogens. In response to such elements, plants activate a variety of defense mechanisms to counteract the aggressiveness of biotic stressors. RNA interference (RNAi) is a key biological process in plants to inhibit gene expression both transcriptionally and post-transcriptionally, using three different groups of proteins to resist the virulence of pathogens. However, pathogens trigger an anti-silencing mechanism through the expression of suppressors to block host RNAi. The disruption of the silencing mechanism is a virulence strategy of pathogens to promote infection in the invaded hosts. In this review, we summarize the RNA silencing pathway, anti-silencing suppressors, and counter-defenses of plants to viral, fungal, and bacterial pathogens.
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CMV2b-Dependent Regulation of Host Defense Pathways in the Context of Viral Infection. Viruses 2018; 10:v10110618. [PMID: 30423959 PMCID: PMC6265714 DOI: 10.3390/v10110618] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/06/2018] [Accepted: 11/08/2018] [Indexed: 01/26/2023] Open
Abstract
RNA silencing (or RNA interference, RNAi) plays direct roles in plant host defenses against viruses. Viruses encode suppressors of RNAi (VSRs) to counteract host antiviral defenses. The generation of transgenic plants expressing VSRs facilitates the understanding of the mechanisms of VSR-mediated interference with the endogenous silencing pathway. However, studying VSRs independent of other viral components simplifies the complex roles of VSRs during natural viral infection. While suppression of transgene silencing by the VSR 2b protein encoded by cucumber mosaic virus (CMV) requires 2b-small RNA (sRNA) binding activity, suppression of host antiviral defenses requires the binding activity of both sRNAs and AGOs proteins. This study, aimed to understand the functions of 2b in the context of CMV infection; thus, we performed genome-wide analyses of differential DNA methylation regions among wild-type CMV-infected, CMVΔ2b-infected, and 2b-transgenic Arabidopsis plants. These analyses, together with transcriptome sequencing and RT-qPCR analyses, show that while the majority of induced genes in 2b-transgenic plants were involved in extensive metabolic pathways, CMV-infection 2b-dependent induced genes were enriched in plant immunity pathways, including salicylic acid (SA) signaling. Together with infection with CMV mutants that expressed the 2b functional domains of sRNA or AGO binding, our data demonstrate that CMV-accelerated SA signaling depends on 2b-sRNA binding activity which is also responsible for virulence.
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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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Yang Z, Li Y. Dissection of RNAi-based antiviral immunity in plants. Curr Opin Virol 2018; 32:88-99. [PMID: 30388659 DOI: 10.1016/j.coviro.2018.08.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 08/03/2018] [Accepted: 08/05/2018] [Indexed: 10/28/2022]
Abstract
RNA interference (RNAi)-based antiviral defense is a small RNA-dependent repression mechanism of plants to against viruses. Although the core components of antiviral RNAi are well known, it is unclear whether additional factors exist that regulate RNAi. Recently, a forward genetic screen identified two novel components of antiviral RNAi, providing important insights into the antiviral RNAi mechanism. Meanwhile, it was discovered that microRNAs make important contributions to host antiviral RNAi. On the other hand, to counteract host antiviral RNAi, most viruses encode viral suppressors of RNA silencing (VSRs). Recent studies have revealed the multiple functions of VSRs and the intricate interactions between plant hosts and viruses. These findings add to our knowledge of the sophisticated host antiviral defense mechanism in plants. Ongoing molecular functional studies will improve our understanding of the co-evolutionary arms race between viruses and plants, and thereby provide key information for the development of plant antiviral strategies.
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Affiliation(s)
- Zhirui Yang
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China
| | - Yi Li
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, China.
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46
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Shi J, Yu L, Song B. Proteomics analysis of Xiangcaoliusuobingmi-treated Capsicum annuum L. infected with Cucumber mosaic virus. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 149:113-122. [PMID: 30033007 DOI: 10.1016/j.pestbp.2018.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/22/2018] [Accepted: 06/13/2018] [Indexed: 05/24/2023]
Abstract
Among different viruses, Cucumber mosaic virus (CMV) has the most extensive host range, being capable of infecting over 1200 species, and causes severe damage worldwide. Xiangcaoliusuobingmi (B1), a candidate plant immune activator drug, exhibited significant protective effects against CMV. However, its potential mechanism is still unknown. In this study, we found the defensive enzyme activities of peroxidase (POD), phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD) and catalase (CAT) can be enhanced by B1. Meanwhile, we found RT-qPCR assay results of the defensive gene expression can be improved by B1 in capsicum. Moreover, we analyze the result of label-free proteomics, B1 could trigger abscisic acid (ABA) pathway. All data provide a more understanding about the response to infect CMV capsicum activeted by B1 in the level of the plant physiology and biochemistry, gene and protein.
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Affiliation(s)
- Jing Shi
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Lu Yu
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China
| | - Baoan Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang 550025, PR China.
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47
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Zhang X, Dong K, Xu K, Zhang K, Jin X, Yang M, Zhang Y, Wang X, Han C, Yu J, Li D. Barley stripe mosaic virus infection requires PKA-mediated phosphorylation of γb for suppression of both RNA silencing and the host cell death response. THE NEW PHYTOLOGIST 2018; 218:1570-1585. [PMID: 29453938 DOI: 10.1111/nph.15065] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/22/2018] [Indexed: 06/08/2023]
Abstract
The Barley stripe mosaic virus (BSMV) γb protein is a viral suppressor of RNA silencing (VSR) and symptom determinant. However, it is unclear how post-translational modification affects the different functions of γb. Here, we demonstrate that γb is phosphorylated at Ser-96 by a PKA-like kinase in vivo and in vitro. Mutant viruses containing a nonphosphorylatable substitution (BSMVS96A or BSMVS96R ) exhibited reduced viral accumulation in Nicotiana benthamiana due to transient induction of the cell death response that constrained the virus to necrotic areas. By contrast, a BSMVS96D mutant virus that mimics γb phosphorylation spread similarly to the wild-type virus. Furthermore, the S96A mutant had reduced local and systemic γb VSR activity due to having compromised its binding activity to 21-bp dsRNA. However, overexpression of other VSRs in trans or in cis failed to rescue the necrosis induced by BSMVS96A , demonstrating that suppression of cell death by γb phosphorylation is functionally distinct from its RNA silencing suppressor activities. These results provide new insights into the function of γb phosphorylation in regulating RNA silencing and the BSMV-induced host cell death response, and contribute to our understanding of how the virus optimizes the balance between viral replication and virus survival in the host plants during virus infection.
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Affiliation(s)
- Xuan Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Kai Dong
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, 210046, China
| | - Kun Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xuejiao Jin
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Meng Yang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yongliang Zhang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Xianbing Wang
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Chenggui Han
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Jialin Yu
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Dawei Li
- State Key Laboratory of Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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48
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Affiliation(s)
- Yu Huang
- College of Life Sciences, Peking University, Beijing, China
| | - Yi Li
- College of Life Sciences, Peking University, Beijing, China.
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49
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Chen C, Chen Y, Jian H, Yang D, Dai Y, Pan L, Shi F, Yang S, Liu Q. Large-Scale Identification and Characterization of Heterodera avenae Putative Effectors Suppressing or Inducing Cell Death in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2017; 8:2062. [PMID: 29379510 PMCID: PMC5775296 DOI: 10.3389/fpls.2017.02062] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/17/2017] [Indexed: 05/06/2023]
Abstract
Heterodera avenae is one of the most important plant pathogens and causes vast losses in cereal crops. As a sedentary endoparasitic nematode, H. avenae secretes effectors that modify plant defenses and promote its biotrophic infection of its hosts. However, the number of effectors involved in the interaction between H. avenae and host defenses remains unclear. Here, we report the identification of putative effectors in H. avenae that regulate plant defenses on a large scale. Our results showed that 78 of the 95 putative effectors suppressed programmed cell death (PCD) triggered by BAX and that 7 of the putative effectors themselves caused cell death in Nicotiana benthamiana. Among the cell-death-inducing effectors, three were found to be dependent on their specific domains to trigger cell death and to be expressed in esophageal gland cells by in situ hybridization. Ten candidate effectors that suppressed BAX-triggered PCD also suppressed PCD triggered by the elicitor PsojNIP and at least one R-protein/cognate effector pair, suggesting that they are active in suppressing both pattern-triggered immunity (PTI) and effector-triggered immunity (ETI). Notably, with the exception of isotig16060, these putative effectors could also suppress PCD triggered by cell-death-inducing effectors from H. avenae, indicating that those effectors may cooperate to promote nematode parasitism. Collectively, our results indicate that the majority of the tested effectors of H. avenae may play important roles in suppressing cell death induced by different elicitors in N. benthamiana.
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Affiliation(s)
- Changlong Chen
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yongpan Chen
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Heng Jian
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Dan Yang
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Yiran Dai
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Lingling Pan
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Qinzhou Entry-Exit Inspection and Quarantine Bureau, Guangxi, China
| | - Fengwei Shi
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- Central Political and Legal Affairs Commission of CPC Chengwu County Committee, Shandong, China
| | - Shanshan Yang
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Qian Liu
- Key Laboratory of Pest Monitoring and Green Management, Ministry of Agriculture, Department of Plant Pathology, China Agricultural University, Beijing, China
- *Correspondence: Qian Liu,
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