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Zhao Y, He Y, Chen X, Li N, Yang T, Hu T, Duan S, Luo X, Jiang L, Chen X, Tao X, Chen J. Different viral effectors hijack TCP17, a key transcription factor for host Auxin synthesis, to promote viral infection. PLoS Pathog 2024; 20:e1012510. [PMID: 39208401 PMCID: PMC11389919 DOI: 10.1371/journal.ppat.1012510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 09/11/2024] [Accepted: 08/15/2024] [Indexed: 09/04/2024] Open
Abstract
Auxin is an important class of plant hormones that play an important role in plant growth development, biotic stress response, and viruses often suppress host plant auxin levels to promote infection. However, previous research on auxin-mediated disease resistance has focused mainly on signaling pathway, and the molecular mechanisms of how pathogenic proteins manipulate the biosynthetic pathway of auxin remain poorly understood. TCP is a class of plant-specific transcription factors, of which TCP17 is a member that binds to the promoter of YUCCAs, a key rate-limiting enzyme for auxin synthesis, and promotes the expression of YUCCAs, which is involved in auxin synthesis in plants. In this study, we reported that Tomato spotted wilt virus (TSWV) infection suppressed the expression of YUCCAs through its interaction with TCP17. Further studies revealed that the NSs protein encoded by TSWV disrupts the dimerization of TCP17, thereby inhibit its transcriptional activation ability and reducing the auxin content in plants. Consequently, this interference inhibits the auxin response signal and promotes the TSWV infection. Transgenic plants overexpressing TCP17 exhibit resistance against TSWV infection, whereas plants knocking out TCP17 were more susceptible to TSWV infection. Additionally, proteins encoded by other RNA viruses (BSMV, RSV and TBSV) can also interact with TCP17 and interfere with its dimerization. Notably, overexpression of TCP17 enhanced resistance against BSMV. This suggests that TCP17 plays a crucial role in plant defense against different types of plant viruses that use viral proteins to target this key component of auxin synthesis and promote infection.
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Affiliation(s)
- Yanxiao Zhao
- School of Plant Protection, Anhui Agricultural University, Hefei, China
- The Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yong He
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Xinyue Chen
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Ninghong Li
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Tongqing Yang
- The Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Tingting Hu
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Shujing Duan
- School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Xuanjie Luo
- The Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Lei Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Xiaoyang Chen
- School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Xiaorong Tao
- The Key Laboratory of Plant Immunity, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jing Chen
- School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
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Gui M, Hu H, Jia Z, Gao X, Tao H, Li Y, Liu Y. Full-length RNA sequencing reveals the mechanisms by which an TSWV-HCRV complex suppresses plant basal resistance. FRONTIERS IN PLANT SCIENCE 2023; 14:1108552. [PMID: 37035074 PMCID: PMC10074851 DOI: 10.3389/fpls.2023.1108552] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/15/2023] [Indexed: 06/19/2023]
Abstract
Viruses deploy numerous strategies to infect plants, typically by forming complexes with another virus, leading to more efficient infection. However, the detailed plant responses to viral infection and the underlying mechanisms of co-infection remain unclear. Previously, we found that tomato spotted wilt orthotospovirus (TSWV) and Hippeastrum chlorotic ringspot orthotospovirus (HCRV) could infect plants in the field by forming a complex. In this study, we found that TSWV infected tobacco (Nicotiana benthamiana) plants in cooperation with HCRV, leading to a more efficient infection rate of both viruses. We then used the in-depth full-length transcriptome to analyze the responses of N. benthamiana to complex infection by TSWV-HCRV (TH). We found that infection with individual TSWV and HCRV triggered plant defense responses, including the jasmonic acid signaling pathway, autophagy, and secondary metabolism. However, TH co-infection could not trigger and even suppress some genes that are involved in these basal resistance responses, suggesting that co-infection is advantageous for the virus and not for the plants. Typically, the TH complex inhibits NbPR1 expression to suppress tobacco resistance. Moreover, the TH complex could alter the expression of microRNAs (miRNAs), especially novel-m0782-3p and miR1992-3p, which directly interact with NbSAM and NbWRKY6 and suppress their expression in tobacco, leading to downregulation of NbPR1 and loss of resistance in tobacco to TSWV and HCRV viruses. Overall, our results elucidated the co-infection mechanisms of TH in tobacco by deploying the miRNA of plants to suppress plant basal resistance and contributed to developing a novel strategy to control crop disease caused by this virus complex.
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Affiliation(s)
- Min Gui
- College of Plant Protection, Yunnan Agricultural University, Kunming, China
- Horticultural Research Institute, Yunnan Academy of Agricultural Science, Kunming, China
| | - Huaran Hu
- Horticultural Research Institute, Yunnan Academy of Agricultural Science, Kunming, China
| | - Zhiqiang Jia
- College of Plant Protection, Yunnan Agricultural University, Kunming, China
| | - Xue Gao
- College of Life Science and Technology, Honghe University, Mengzi, China
| | - Hongzheng Tao
- College of Life Science and Technology, Honghe University, Mengzi, China
| | - Yongzhong Li
- College of Tobacco, Yunnan Agricultural University, Kunming, China
| | - Yating Liu
- College of Tobacco, Yunnan Agricultural University, Kunming, China
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Wu H, Liu M, Kang B, Liu L, Hong N, Peng B, Gu Q. AC5 protein encoded by squash leaf curl China virus is an RNA silencing suppressor and a virulence determinant. Front Microbiol 2022; 13:980147. [PMID: 36060769 PMCID: PMC9437540 DOI: 10.3389/fmicb.2022.980147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/05/2022] [Indexed: 11/26/2022] Open
Abstract
Squash leaf curl China virus (SLCCNV) is a bipartite Begomovirus. The function of the protein AC5, which is encoded by SLCCNV, is unknown. Here, we confirmed that the 172-amino acids (aa) long AC5 protein of SLCCNV could suppress single-stranded RNA but not double-stranded RNA-induced post-transcriptional gene silencing (PTGS). Furthermore, we determined that the C-terminal domain (96–172 aa) of the AC5 protein was responsible for RNA silencing suppressor (RSS) activity via deletion mutant analysis. The AC5 protein can reverse GFP silencing and inhibit systemic silencing of GFP by interfering with the systemic spread of the GFP silencing signal. The SLCCNV AC5 protein was localized to both the nucleus and cytoplasm of Nicotiana benthamiana cells. Furthermore, deletion analysis showed that the putative nuclear localization signal (NLS, 102–155 aa) was crucial for the RNA silencing suppression activity of AC5. In addition, the AC5 protein elicited a hypersensitive response and enhanced potoao virus X (PVX) RNA accumulation in infected N. benthamiana plants. Using the infectious clones of the SLCCNV and SLCCNV-AC5 null mutants, mutational analysis confirmed that knockout of the AC5 gene abolished SLCCNV-induced leaf curl symptoms, showing SLCCNV AC5 is also a virulence determinant.
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Affiliation(s)
- Huijie Wu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Mei Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Baoshan Kang
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Liming Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Ni Hong
- College of Plant Science and Technology, Huazhong Agricultural University/Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Bin Peng
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- Bin Peng,
| | - Qinsheng Gu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- *Correspondence: Qinsheng Gu,
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Gao X, Jia ZQ, Tao HZ, Xu Y, Li YZ, Liu YT. Use of deep sequencing to profile small RNAs derived from tomato spotted wilt orthotospovirus and hippeastrum chlorotic ringspot orthotospovirus in infected Capsicum annuum. Virus Res 2021; 309:198648. [PMID: 34910964 DOI: 10.1016/j.virusres.2021.198648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 10/19/2022]
Abstract
Virus-derived small RNAs are one of the key factors of RNA silencing in plant defence against viruses. We obtained virus-derived small interfering RNA profiles from Tomato spotted wilt orthotospovirus and Hippeastrum chlorotic ringspot orthotospovirus infected Capsicum annuum XX19 and XY11 by deep sequencing one day after inoculation. The vsiRNAs data were mapped to the TSWV and HCRV genomes, and the results showed that the vsiRNAs measured 19-24 nucleotides in length. Most of the vsiRNAs were mapped to the S segment of the viral genome. For XX19 and XY11 infected with HCRV, the distribution range of vsiRNAs in S RNA was 52.06-55.20%, while for XX19 and XY11 infected with TSWV, the distribution range of vsiRNAs in S RNA was 87.76-89.07%. The first base at the 5' end of the siRNA from TSWV and HCRV was primarily biased towards A, U, or C. Compared with mock-inoculated XX19 and XY11, the expression level of CaRDR1 was upregulated in TSWV- and HCRV-inoculated XX19 and XY11. CaAGO2 and CaAGO5 were upregulated in XY11 against HCRV infection, and CaRDR2 was downregulated in TSWV-infected XY11 and XX19. The profile of HCRV and TSWV vsiRNA verified in this study could be useful for selecting key vsiRNA such as those in disease-resistant varieties by artificially synthesizing amiRNA.
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Affiliation(s)
- Xue Gao
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China
| | - Zhi-Qiang Jia
- College of Plant Protection, Yunnan Agricultural University, Kunming, 650201, China
| | - Hong-Zheng Tao
- College of Plant Protection, Yunnan Agricultural University, Kunming, 650201, China; School of Life Science and Technology, Honghe University, Mengzi, 661199, China
| | - Ye Xu
- College of Public Health, Southern Medical University, Guangzhou, 510515, China
| | - Yong-Zhong Li
- College of Tobacco Science, Yunnan Agricultural University, Kunming 650201, China.
| | - Ya-Ting Liu
- College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China.
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Qi S, Zhang S, Islam MM, El-Sappah AH, Zhang F, Liang Y. Natural Resources Resistance to Tomato Spotted Wilt Virus (TSWV) in Tomato ( Solanum lycopersicum). Int J Mol Sci 2021; 22:ijms222010978. [PMID: 34681638 PMCID: PMC8538096 DOI: 10.3390/ijms222010978] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/26/2022] Open
Abstract
Tomato spotted wilt virus (TSWV) is one of the most destructive diseases affecting tomato (Solanum lycopersicum) cultivation and production worldwide. As defenses against TSWV, natural resistance genes have been identified in tomato, including Sw-1a, Sw-1b, sw-2, sw-3, sw-4, Sw-5, Sw-6, and Sw-7. However, only Sw-5 exhibits a high level of resistance to the TSWV. Thus, it has been cloned and widely used in the breeding of tomato with resistance to the disease. Due to the global spread of TSWV, resistance induced by Sw-5 decreases over time and can be overcome or broken by a high concentration of TSWV. How to utilize other resistance genes and identify novel resistance resources are key approaches for breeding tomato with resistance to TSWV. In this review, the characteristics of natural resistance genes, natural resistance resources, molecular markers for assisted selection, and methods for evaluating resistance to TSWV are summarized. The aim is to provide a theoretical basis for identifying, utilizing resistance genes, and developing tomato varieties that are resistant to TSWV.
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Affiliation(s)
- Shiming Qi
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
| | - Shijie Zhang
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
| | - Md. Monirul Islam
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
| | - Ahmed H. El-Sappah
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
- Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt
| | - Fei Zhang
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
| | - Yan Liang
- College of Horticulture, Northwest A&F University, Xianyang 712100, China; (S.Q.); (S.Z.); (M.M.I.); (A.H.E.-S.); (F.Z.)
- State Agriculture Ministry Laboratory of Northwest Horticultural Plant Germplasm Resources & Genetic Improvement, Northwest A&F University, Xianyang 712100, China
- Correspondence: ; Tel.: +86-29-8708-2613
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Kormelink R, Verchot J, Tao X, Desbiez C. The Bunyavirales: The Plant-Infecting Counterparts. Viruses 2021; 13:842. [PMID: 34066457 PMCID: PMC8148189 DOI: 10.3390/v13050842] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 12/18/2022] Open
Abstract
Negative-strand (-) RNA viruses (NSVs) comprise a large and diverse group of viruses that are generally divided in those with non-segmented and those with segmented genomes. Whereas most NSVs infect animals and humans, the smaller group of the plant-infecting counterparts is expanding, with many causing devastating diseases worldwide, affecting a large number of major bulk and high-value food crops. In 2018, the taxonomy of segmented NSVs faced a major reorganization with the establishment of the order Bunyavirales. This article overviews the major plant viruses that are part of the order, i.e., orthospoviruses (Tospoviridae), tenuiviruses (Phenuiviridae), and emaraviruses (Fimoviridae), and provides updates on the more recent ongoing research. Features shared with the animal-infecting counterparts are mentioned, however, special attention is given to their adaptation to plant hosts and vector transmission, including intra/intercellular trafficking and viral counter defense to antiviral RNAi.
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Affiliation(s)
- Richard Kormelink
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Jeanmarie Verchot
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA;
| | - Xiaorong Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China;
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Current Status and Potential of RNA Interference for the Management of Tomato Spotted Wilt Virus and Thrips Vectors. Pathogens 2021; 10:pathogens10030320. [PMID: 33803131 PMCID: PMC8001667 DOI: 10.3390/pathogens10030320] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/20/2021] [Accepted: 02/27/2021] [Indexed: 12/16/2022] Open
Abstract
Tomato spotted wilt virus (TSWV) is the type member of the genus Orthotospovirus in the family Tospoviridae and order Bunyavirales. TSWV, transmitted by several species of thrips, causes significant disease losses to agronomic and horticultural crops worldwide, impacting both the yield and quality of the produce. Management strategies include growing virus-resistant cultivars, cultural practices, and managing thrips vectors through pesticide application. However, numerous studies have reported that TSWV isolates can overcome host-plant resistance, while thrips are developing resistance to pesticides that were once effective. RNA interference (RNAi) offers a means of host defence by using double-stranded (ds) RNA to initiate gene silencing against invading viruses. However, adoption of this approach requires production and use of transgenic plants and thus limits the practical application of RNAi against TSWV and other viruses. To fully utilize the potential of RNAi for virus management at the field level, new and novel approaches are needed. In this review, we summarize RNAi and highlight the potential of topical or exogenous application of RNAi triggers for managing TSWV and thrips vectors.
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Cowley JA. The genomes of Mourilyan virus and Wēnzhōu shrimp virus 1 of prawns comprise 4 RNA segments. Virus Res 2020; 292:198225. [PMID: 33181202 DOI: 10.1016/j.virusres.2020.198225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 12/16/2022]
Abstract
Reported here is the complete genome sequence of Mourilyan virus (MoV) that infects giant tiger (Penaeus monodon) and kuruma prawns (P. japonicas) in Australia. Its genome was determined using various PCR strategies based on the sequences of 3 randomly-amplified cDNA clones to its L and M RNA segments discovered in a library generated to determine the genome sequence of gill-associated ronivirus. The sequences of PCR products and clones obtained showed the MoV genome to comprise 4 ssRNA segments (L, M, S1 and S2), as confirmed by Northern blotting using RNA from naïve and MoV-infected prawns, and by Illumina sequence analysis of semi-purified MoV. BLASTn searches identified the MoV L, M and S1 RNA segments to be homologous to Wēnzhōu shrimp virus 1 (WzSV1) segments discovered recently in a P. monodon RNA-Seq library (SRR1745808). Mapping this read library to the MoV S2 RNA segment identified WzSV1 to also possess an equivalent segment. BLASTp searches identified the putative non-structural protein (NSs2; 393-394 aa) encoded in their S2 RNA segments to have no homologs in GenBank. Possibly due to NSs2 being encoded in a discrete RNA segment rather than in ambisense relative to the N protein as in the S RNA segments of other phenuiviruses, each of 6 MoV S1 RNA segment clones sequenced possessed a variable-length (≤ 645 nt) imperfect GA-repeat extending from the N protein stop codon to the more variable ∼90 nt segment terminal sequence. Read mapping of RNA-Seq library SRR1745808 showed the WzSV1 S1 RNA segment to possess a similar GA-repeat. However, paired-read variations hindered definitive assembly of a consensus sequence. All 4 MoV and WzSV1 RNA segments terminated with a 10 nt inverted repeat sequence (5'-ACACAAAGAC.) identical to the RNA segment termini of uukuviruses. Phylogenetic analyses of MoV/WzSV1 RNA-dependant RNA polymerase (L RNA), G1G2 precursor glycoprotein (M RNA) and nucleocapsid (N) protein (S1 RNA) sequences generally clustered them with as yet unassigned crustacean/diptera bunya-like viruses on branches positioned closely to others containing tick-transmitted phenuiviruses. As genome sequences of most phenuiviruses discovered recently have originated from meta-transcriptomics studies, the data presented here showing the MoV and WzSV1 genomes to comprise more than 3 RNA segments, like the plant tenuiviruses, suggests a need to investigate the genomes of these unassigned viruses more closely.
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Affiliation(s)
- Jeff A Cowley
- Livestock & Aquaculture, CSIRO Agriculture & Food, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia, QLD, 4067, Australia.
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Wu X, Xu S, Zhao P, Zhang X, Yao X, Sun Y, Fang R, Ye J. The Orthotospovirus nonstructural protein NSs suppresses plant MYC-regulated jasmonate signaling leading to enhanced vector attraction and performance. PLoS Pathog 2019; 15:e1007897. [PMID: 31206553 PMCID: PMC6598649 DOI: 10.1371/journal.ppat.1007897] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/27/2019] [Accepted: 06/05/2019] [Indexed: 11/19/2022] Open
Abstract
Pandemics of vector-borne human and plant diseases often depend on the behaviors
of their arthropod vectors. Arboviruses, including many bunyaviruses, manipulate
vector behavior to accelerate their own transmission to vertebrates, birds,
insects, and plants. However, the molecular mechanism underlying this
manipulation remains elusive. Here, we report that the non-structural protein
NSs of Tomato spotted wilt orthotospovirus, a prototype of the
Tospoviridae family and the
Orthotospovirus genus, is a key viral factor that
indirectly modifies vector preference and increases vector performance. NSs
suppresses the biosynthesis of plant volatile monoterpenes, which serve as
repellents of the vector western flower thrips (WFT, Frankliniella
occidentalis). NSs directly interacts with MYC2, the jasmonate (JA)
signaling master regulator and its two close homologs MYC3 and MYC4, to disable
JA-mediated activation of terpene synthase genes. The
dysfunction of the MYCs subsequently attenuates host defenses, increases the
attraction of thrips, and improves thrips fitness. Moreover, MYC2 associated
with NSs of Tomato zonate spot orthotospovirus, another Euro/Asian-type
orthotospovirus, suggesting that MYC2 is an evolutionarily conserved target of
Orthotospovirus species for suppression of terpene-based
resistance to promote vector performance. These findings elucidate the molecular
mechanism through which an orthotospovirus indirectly manipulates vector
behaviors and therefore facilitates pathogen transmission. Our results provide
insights into the molecular mechanisms by which Orthotospovirus
NSs counteracts plant immunity for pathogen transmission. Most bunyaviruses are transmitted by arthropod vectors, and some of them can
modify the behaviors of their arthropod vectors to increase transmission to
mammals, birds, and plants. NSs is a non-structural bunyavirus protein with
multiple functions that acts as an avirulence determinant and silencing
suppressor. In this study, we identified a new function of NSs as a conserved
manipulator of vector behavior via plant. NSs suppresses jasmonate-mediated
plant immunity against thrips by directly interacting with several homologs of
MYC transcription factors, the core regulators of the jasmonate-signaling
pathway. This hijacking by NSs enhances thrips preference and performance.
Therefore, our data support the hypothesis that MYC2 is a convergent target that
plant pathogens manipulate to promote their survival in plants.
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Affiliation(s)
- Xiujuan Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing,
China
| | - Shuang Xu
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing,
China
| | - Pingzhi Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
| | - Xuan Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
| | - Xiangmei Yao
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
| | - Yanwei Sun
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
| | - Rongxiang Fang
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing,
China
| | - Jian Ye
- State Key Laboratory of Plant Genomics, Institute of Microbiology,
Chinese Academy of Sciences, Beijing, China
- University of the Chinese Academy of Sciences, Beijing,
China
- * E-mail:
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Tomato Spotted Wilt Virus NSs Protein Supports Infection and Systemic Movement of a Potyvirus and Is a Symptom Determinant. Viruses 2018. [PMID: 29538326 PMCID: PMC5869522 DOI: 10.3390/v10030129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Plant viruses are inducers and targets of antiviral RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressor proteins that interfere with antiviral RNA silencing. The NSs protein is an RNA silencing suppressor in orthotospoviruses, such as the tomato spotted wilt virus (TSWV). The mechanism of RNA silencing suppression by NSs and its role in virus infection and movement are poorly understood. Here, we cloned and tagged TSWV NSs and expressed it from a GFP-tagged turnip mosaic virus (TuMV-GFP) carrying either a wild-type or suppressor-deficient (AS9) helper component proteinase (HC-Pro). When expressed in cis, NSs restored pathogenicity and promoted systemic infection of suppressor-deficient TuMV-AS9-GFP in Nicotiana benthamiana and Arabidopsis thaliana. Inactivating mutations were introduced in NSs RNA-binding domain one. A genetic analysis with active and suppressor-deficient NSs, in combination with wild-type and mutant plants lacking essential components of the RNA silencing machinery, showed that the NSs insert is stable when expressed from a potyvirus. NSs can functionally replace potyviral HC-Pro, condition virus susceptibility, and promote systemic infection and symptom development by suppressing antiviral RNA silencing through a mechanism that partially overlaps that of potyviral HC-Pro. The results presented provide new insight into the mechanism of silencing suppression by NSs and its effect on virus infection.
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