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Kamal H, Zafar MM, Razzaq A, Parvaiz A, Ercisli S, Qiao F, Jiang X. Functional role of geminivirus encoded proteins in the host: Past and present. Biotechnol J 2024; 19:e2300736. [PMID: 38900041 DOI: 10.1002/biot.202300736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/19/2024] [Accepted: 04/16/2024] [Indexed: 06/21/2024]
Abstract
During plant-pathogen interaction, plant exhibits a strong defense system utilizing diverse groups of proteins to suppress the infection and subsequent establishment of the pathogen. However, in response, pathogens trigger an anti-silencing mechanism to overcome the host defense machinery. Among plant viruses, geminiviruses are the second largest virus family with a worldwide distribution and continue to be production constraints to food, feed, and fiber crops. These viruses are spread by a diverse group of insects, predominantly by whiteflies, and are characterized by a single-stranded DNA (ssDNA) genome coding for four to eight proteins that facilitate viral infection. The most effective means to managing these viruses is through an integrated disease management strategy that includes virus-resistant cultivars, vector management, and cultural practices. Dynamic changes in this virus family enable the species to manipulate their genome organization to respond to external changes in the environment. Therefore, the evolutionary nature of geminiviruses leads to new and novel approaches for developing virus-resistant cultivars and it is essential to study molecular ecology and evolution of geminiviruses. This review summarizes the multifunctionality of each geminivirus-encoded protein. These protein-based interactions trigger the abrupt changes in the host methyl cycle and signaling pathways that turn over protein normal production and impair the plant antiviral defense system. Studying these geminivirus interactions localized at cytoplasm-nucleus could reveal a more clear picture of host-pathogen relation. Data collected from this antagonistic relationship among geminivirus, vector, and its host, will provide extensive knowledge on their virulence mode and diversity with climate change.
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Affiliation(s)
- Hira Kamal
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA
| | - Muhammad Mubashar Zafar
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
| | - Abdul Razzaq
- Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan
| | - Aqsa Parvaiz
- Department of Biochemistry and Biotechnology, The Women University Multan, Multan, Pakistan
| | - Sezai Ercisli
- Department of Horticulture, Faculty of Agriculture, Ataturk University, Erzurum, Turkey
| | - Fei Qiao
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
| | - Xuefei Jiang
- Sanya Institute of Breeding and Multiplication, School of Tropical Agriculture and Forestry, Hainan University, Sanya, China
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2
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Chergintsev DA, Solovieva AD, Atabekova AK, Lezzhov AA, Golyshev SA, Morozov SY, Solovyev AG. Properties of Plant Virus Protein Encoded by the 5'-Proximal Gene of Tetra-Cistron Movement Block. Int J Mol Sci 2023; 24:14144. [PMID: 37762447 PMCID: PMC10532019 DOI: 10.3390/ijms241814144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
To move from cell to cell through plasmodesmata, many plant viruses require the concerted action of two or more movement proteins (MPs) encoded by transport gene modules of virus genomes. A tetra-cistron movement block (TCMB) is a newly discovered transport module comprising four genes. TCMB encodes three proteins, which are similar to MPs of the transport module known as the "triple gene block", and a protein unrelated to known viral MPs and containing a double-stranded RNA (dsRNA)-binding domain similar to that found in a family of cell proteins, including AtDRB4 and AtHYL1. Here, the latter TCMB protein, named vDRB for virus dsRNA-binding protein, is shown to bind both dsRNA and single-stranded RNA in vitro. In a turnip crinkle virus-based assay, vDRB exhibits the properties of a viral suppressor of RNA silencing (VSR). In the context of potato virus X infection, vDRB significantly decreases the number and size of "dark green islands", regions of local antiviral silencing, supporting the VSR function of vDRB. Nevertheless, vDRB does not exhibit the VSR properties in non-viral transient expression assays. Taken together, the data presented here indicate that vDRB is an RNA-binding protein exhibiting VSR functions in the context of viral infection.
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Affiliation(s)
- Denis A. Chergintsev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anna D. Solovieva
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Anastasia K. Atabekova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Alexander A. Lezzhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergei A. Golyshev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
| | - Sergey Y. Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
| | - Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia; (D.A.C.); (A.K.A.); (A.A.L.); (S.A.G.); (S.Y.M.)
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia;
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3
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Zwolinski AM, Brigden A, Rey MEC. Differences in the 3' intergenic region and the V2 protein of two sequence variants of tomato curly stunt virus play an important role in disease pathology in Nicotiana benthamiana. PLoS One 2023; 18:e0286149. [PMID: 37220127 DOI: 10.1371/journal.pone.0286149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 05/10/2023] [Indexed: 05/25/2023] Open
Abstract
Tomato production in South Africa is threatened by the emergence of tomato curly stunt virus (ToCSV), a monopartite Begomovirus transmitted by the whitefly vector Bemisia tabaci (Genn.). We investigated the role of sequence differences present in the 3' intergenic region (IR) and the V2 coding region on the differing infectivity of ToCSV sequence variant isolates V30 and V22 in the model host Nicotiana benthamiana. Using virus mutant chimeras, we determined that the development of the upward leaf roll symptom phenotype is mediated by sequence differences present in the 3' IR containing the TATA-associated composite element. Sequence differences present in the V2 coding region are responsible for modulating disease severity and symptom recovery in V22-infected plants. Serine substitution of V22 V2 Val27 resulted in a significant increase in disease severity with reduced recovery, the first study to demonstrate the importance of this V2 residue in disease development. Two putative ORFs, C5 and C6, were identified using in silico analysis and detection of an RNA transcript spanning their coding region suggests that these ORFs may be transcribed during infection. Additional virus-derived RNA transcripts spanning multiple ORFs and crossing the boundaries of recognised polycistronic transcripts, as well as the origin of replication within the IR, were detected in ToCSV-infected plants providing evidence of bidirectional readthrough transcription. From our results, we conclude that the diverse responses of the model host to ToCSV infection is influenced by select sequence differences and our findings provide several avenues for further investigation into the mechanisms behind these responses to infection.
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Affiliation(s)
- Alexander M Zwolinski
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Alison Brigden
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
| | - Marie E C Rey
- School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
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4
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Zhang J, Ma M, Liu Y, Ismayil A. Plant Defense and Viral Counter-Defense during Plant-Geminivirus Interactions. Viruses 2023; 15:v15020510. [PMID: 36851725 PMCID: PMC9964946 DOI: 10.3390/v15020510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
Geminiviruses are the largest family of plant viruses that cause severe diseases and devastating yield losses of economically important crops worldwide. In response to geminivirus infection, plants have evolved ingenious defense mechanisms to diminish or eliminate invading viral pathogens. However, increasing evidence shows that geminiviruses can interfere with plant defense response and create a suitable cell environment by hijacking host plant machinery to achieve successful infections. In this review, we discuss recent findings about plant defense and viral counter-defense during plant-geminivirus interactions.
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Affiliation(s)
- Jianhang Zhang
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, College of Life Sciences, Shihezi University, Shihezi 832003, China
| | - Mengyuan Ma
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, College of Life Sciences, Shihezi University, Shihezi 832003, China
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing 100084, China
| | - Asigul Ismayil
- Key Laboratory of Xinjiang Phytomedicine Resource and Utilization of Ministry of Education, College of Life Sciences, Shihezi University, Shihezi 832003, China
- Correspondence:
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5
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Bahari A, Castillo AG, Safaie N, Bejarano ER, Luna AP, Shams-Bakhsh M. Functional Analysis of V2 Protein of Beet Curly Top Iran Virus. PLANTS (BASEL, SWITZERLAND) 2022; 11:3351. [PMID: 36501393 PMCID: PMC9736138 DOI: 10.3390/plants11233351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 06/17/2023]
Abstract
Geminivirus beet curly top Iran virus (BCTIV) is one of the main causal agents of the beet curly top disease in Iran and the newly established Becurtovirus genus type species. Although the biological features of known becurtoviruses are similar to those of curtoviruses, they only share a limited sequence identity, and no information is available on the function of their viral genes. In this work, we demonstrate that BCTIV V2, as the curtoviral V2, is also a local silencing suppressor in Nicotiana benthamiana and can delay the systemic silencing spreading, although it cannot block the cell-to-cell movement of the silencing signal to adjacent cells. BCTIV V2 shows the same subcellular localization as curtoviral V2, being detected in the nucleus and perinuclear region, and its ectopic expression from a PVX-derived vector also causes the induction of necrotic lesions in N. benthamiana, such as the ones produced during the HR, both at the local and systemic levels. The results from the infection of N. benthamiana with a V2 BCTIV mutant showed that V2 is required for systemic infection, but not for viral replication, in a local infection. Considering all these results, we can conclude that BCTIV V2 is a functional homologue of curtoviral V2 and plays a crucial role in viral pathogenicity and systemic movement.
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Affiliation(s)
- Atiyeh Bahari
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
| | - Araceli G. Castillo
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Naser Safaie
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
| | - Eduardo R. Bejarano
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Ana P. Luna
- Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, 29010 Malaga, Spain
| | - Masoud Shams-Bakhsh
- Plant Pathology Department, Faculty of Agriculture, Tarbiat Modares University (TMU), Tehran 336-14115, Iran
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6
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Devendran R, Namgial T, Reddy KK, Kumar M, Zarreen F, Chakraborty S. Insights into the multifunctional roles of geminivirus-encoded proteins in pathogenesis. Arch Virol 2022; 167:307-326. [PMID: 35079902 DOI: 10.1007/s00705-021-05338-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 10/23/2021] [Indexed: 12/18/2022]
Abstract
Geminiviruses are a major threat to agriculture in tropical and subtropical regions of the world. Geminiviruses have small genome with limited coding capacity. Despite this limitation, these viruses have mastered hijacking the host cellular metabolism for their survival. To compensate for the small size of their genome, geminiviruses encode multifunctional proteins. In addition, geminiviruses associate themselves with satellite DNA molecules which also encode proteins that support the virus in establishing successful infection. Geminiviral proteins recruit multiple host factors, suppress the host defense, and manipulate host metabolism to establish infection. We have updated the knowledge accumulated about the proteins of geminiviruses and their satellites in the context of pathogenesis in a single review. We also discuss their interactions with host factors to provide a mechanistic understanding of the infection process.
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Affiliation(s)
- Ragunathan Devendran
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Tsewang Namgial
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Kishore Kumar Reddy
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Manish Kumar
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Fauzia Zarreen
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
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7
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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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8
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Ban F, Zhong Y, Pan L, Mao L, Wang X, Liu Y. Coinfection by Two Begomoviruses Aggravates Plant Symptoms But Does Not Influence the Performance and Preference of Insect Vector Bemisia tabaci (Hemiptera: Aleyrodidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2021; 114:547-554. [PMID: 33503240 DOI: 10.1093/jee/toaa326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Indexed: 06/12/2023]
Abstract
In nature, a plant can be infected by multiple viruses simultaneously. However, the effects of coinfection on plant-vector interactions are less well studied. Two begomoviruses of the family Geminiviridae, Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl China virus (TYLCCNV), occur sympatrically in China. Each of them is reported to increase the performance of whitefly vector via manipulation of plant traits. In this study, we examined the effects of coinfection by the two viruses TYLCV and TYLCCNV on plant-whitefly interactions, compared to that infected by a single virus. We found that plants infected by two viruses showed aggravated symptoms but the performance and preference of whiteflies were not altered significantly compared to singly-infected plants. Coinfection suppressed the transcription of genes involved in jasmonic acid (JA) signaling pathway in plants, but showed no significant difference to single-virus infected plants. These findings suggest that although TYLCV and TYLCCNV may synergistically induce plant symptoms, they did not manipulate synergistically plant-mediated responses to the insect vector.
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Affiliation(s)
- Feixue Ban
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yuwei Zhong
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Lilong Pan
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Lijuan Mao
- Analysis Center of Agrobiology and Environmental Sciences, Faculty of Agriculture, Life and Environment Sciences (ACAES), Zhejiang University, Hangzhou, China
| | - Xiaowei Wang
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yinquan Liu
- Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogen and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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9
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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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10
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Zarreen F, Chakraborty S. Epigenetic regulation of geminivirus pathogenesis: a case of relentless recalibration of defence responses in plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6890-6906. [PMID: 32869846 DOI: 10.1093/jxb/eraa406] [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] [Received: 08/27/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
Geminiviruses constitute one of the largest families of plant viruses and they infect many economically important crops. The proteins encoded by the single-stranded DNA genome of these viruses interact with a wide range of host proteins to cause global dysregulation of cellular processes and help establish infection in the host. Geminiviruses have evolved numerous mechanisms to exploit host epigenetic processes to ensure the replication and survival of the viral genome. Here, we review our current knowledge of diverse epigenetic processes that have been implicated in the regulation of geminivirus pathogenesis, including DNA methylation, histone post-transcriptional modification, chromatin remodelling, and nucleosome repositioning. In addition, we discuss the currently limited evidence of host epigenetic defence responses that are aimed at counteracting geminivirus infection, and the potential for exploiting these responses for the generation of resistance against geminiviruses in crop species.
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Affiliation(s)
- Fauzia Zarreen
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
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11
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Qiu Y, Zhang S, Yu H, Xuan Z, Yang L, Zhan B, Murilo Zerbini F, Cao M. Identification and Characterization of Two Novel Geminiviruses Associated with Paper Mulberry ( Broussonetia papyrifera) Leaf Curl Disease. PLANT DISEASE 2020; 104:3010-3018. [PMID: 32881645 DOI: 10.1094/pdis-12-19-2597-re] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Paper mulberry (Broussonetia papyrifera) is a perennial woody plant used as source material for Cai Lun paper making, in traditional Chinese medicine, and as livestock feed. To identify the presence of viruses in paper mulberry plants affected by a disease with leaf curl symptoms, high-throughput sequencing of total RNA was performed. Analysis of transcriptome libraries allowed the reconstruction of two geminivirus-like genomes. Rolling-circle amplification and PCR with back-to-back primers confirmed the presence of two geminiviruses with monopartite genomes in these plants, with the names paper mulberry leaf curl virus 1 and 2 (PMLCV-1 and PMLCV-2) proposed. The genomes of PMLCV-1 (3,056 nt) and PMLCV-2 (3,757 to 3,763 nt) encode six proteins, with the V4 protein of PMLCV-1 and the V3 proteins of both viruses having low similarities to any known protein in databases. Alternative splicing of an intron, akin to that of mastre-, becurto-, capula-, and grabloviruses, was identified by small RNA (sRNA)-seq and RNA-seq reads mapping to PMLCV-1 and PMLCV-2 antisense transcripts. Phylogenetic analyses and pairwise comparisons showed that PMLCV-1 and PMLCV-2 are most closely related to, but distinct from, two unassigned geminiviruses, citrus chlorotic dwarf associated virus and mulberry mosaic dwarf associated virus, suggesting that they are two new members of the family Geminiviridae. Field investigation confirmed the close association of the two viruses with leaf curl symptoms in paper mulberry plants and that coinfection can aggravate the symptoms.
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Affiliation(s)
- Yuanjian Qiu
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Song Zhang
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Haodong Yu
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Zhiyou Xuan
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Liu Yang
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
| | - Binhui Zhan
- State Key Laboratory for Biology of Plant Disease and Insect Pest, Institute of Plant Protection, Academy of Agricultural Sciences, Beijing 100193, China
| | - F Murilo Zerbini
- Departamento de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil
| | - Mengji Cao
- National Citrus Engineering and Technology Research Center, Citrus Research Institute, Southwest University, Beibei, Chongqing 400712, China
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China
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12
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Vinoth Kumar R, Shivaprasad PV. Plant-virus-insect tritrophic interactions: insights into the functions of geminivirus virion-sense strand genes. Proc Biol Sci 2020; 287:20201846. [PMID: 33049166 DOI: 10.1098/rspb.2020.1846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The genome of the plant-infecting viruses in the family Geminiviridae is composed of one or two circular single stranded DNA of approximately 2.7-5.2 kb in length. These viruses have emerged as the most devastating pathogen infecting a large number of crops and weeds across the continents. They code for fewer open reading frames (ORFs) through the generation of overlapping transcripts derived from the bidirectional viral promoters. Members of geminiviruses code for up to four ORFs in the virion-sense strand, and their gene expression is regulated by various cis-elements located at their promoters in the intergenic region. These viral proteins perform multiple functions at every stage of the viral life cycle such as virus transport, insect-mediated virus transmission and suppression of host defence. They impede the host's multi-layered antiviral mechanisms including gene silencing (at transcriptional and post-transcriptional levels) and hypersensitive response. This review summarizes the essential role of virion-sense strand encoded proteins in transport of viral genomes within and between plant cells, countering defence in hosts (both plants and the insects), and also in the ubiquitous role in vector-mediated transmission. We highlight the significance of their pro-viral activities in manipulating host-derived innate immune responses and the interaction with whitefly-derived proteins. We also discuss the current knowledge on virus replication and transcription within the insect body.
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Affiliation(s)
- R Vinoth Kumar
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), GKVK campus, Bengaluru 560065, Karnataka, India
| | - P V Shivaprasad
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research (TIFR), GKVK campus, Bengaluru 560065, Karnataka, India
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Prasad A, Sharma N, Hari-Gowthem G, Muthamilarasan M, Prasad M. Tomato Yellow Leaf Curl Virus: Impact, Challenges, and Management. TRENDS IN PLANT SCIENCE 2020; 25:897-911. [PMID: 32371058 DOI: 10.1016/j.tplants.2020.03.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 05/26/2023]
Abstract
Tomato yellow leaf curl virus (TYLCV) is one of the most studied plant viral pathogens because it is the most damaging virus for global tomato production. In order to combat this global threat, it is important that we understand the biology of TYLCV and devise management approaches. The prime objective of this review is to highlight management strategies for efficiently tackling TYLCV epidemics and global spread. For that purpose, we focus on the impact TYLCV has on worldwide agriculture and the role of recent advances for our understanding of TYLCV interaction with its host and vector. Another important focus is the role of recombination and mutations in shaping the evolution of TYLCV genome and geographical distribution.
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Affiliation(s)
- Ashish Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Namisha Sharma
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | | | | | - Manoj Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India.
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14
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Luna AP, Romero-Rodríguez B, Rosas-Díaz T, Cerero L, Rodríguez-Negrete EA, Castillo AG, Bejarano ER. Characterization of Curtovirus V2 Protein, a Functional Homolog of Begomovirus V2. FRONTIERS IN PLANT SCIENCE 2020; 11:835. [PMID: 32636860 PMCID: PMC7318802 DOI: 10.3389/fpls.2020.00835] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 05/25/2020] [Indexed: 05/30/2023]
Abstract
Geminiviruses are single-stranded DNA plant viruses with circular genomes packaged within geminate particles. Among the Geminiviridae family, Begomovirus and Curtovirus comprise the two best characterized genera. Curtovirus and Old World begomovirus possess similar genome structures with six to seven open-reading frames (ORF). Among them, begomovirus and curtovirus V2 ORFs share the same location in the viral genome, encode proteins of similar size, but show extremely poor sequence homology between the genera. V2 from Beet curly top virus (BCTV), the model species for the Curtovirus genus, as it begomoviral counterpart, suppresses post-transcriptional gene silencing (PTGS) by impairing the RDR6/SGS3 pathway and localizes in the nucleus spanning from the perinuclear region to the cell periphery. By aminoacid sequence comparison we have identified that curtoviral and begomoviral V2 proteins shared two hydrophobic domains and a putative phosphorylation motif. These three domains are essential for BCTV V2 silencing suppression activity, for the proper nuclear localization of the protein and for systemic infection. The lack of suppression activity in the mutated versions of V2 is complemented by the impaired function of RDR6 in Nicotiana benthamiana but the ability of the viral mutants to produce a systemic infection is not recovered in gene silencing mutant backgrounds. We have also demonstrated that, as its begomoviral homolog, V2 from BCTV is able to induce systemic symptoms and necrosis associated with a hypersensitive response-like (HR-like) when expressed from Potato virus X vector in N. benthamiana, and that this pathogenicity activity does not dependent of its ability to supress PTGS.
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Affiliation(s)
- Ana P Luna
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Beatriz Romero-Rodríguez
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Tábata Rosas-Díaz
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Laura Cerero
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Edgar A Rodríguez-Negrete
- CONACyT, Departamento de Biotecnología Agrícola, Instituto Politécnico Nacional, CIIDIR-Unidad Sinaloa, Guasave, Mexico
| | - Araceli G Castillo
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
| | - Eduardo R Bejarano
- Departamento de Genética, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Universidad de Málaga, Málaga, Spain
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15
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Li H, Li F, Zhang M, Gong P, Zhou X. Dynamic Subcellular Localization, Accumulation, and Interactions of Proteins From Tomato Yellow Leaf Curl China Virus and Its Associated Betasatellite. FRONTIERS IN PLANT SCIENCE 2020; 11:840. [PMID: 32612626 PMCID: PMC7308551 DOI: 10.3389/fpls.2020.00840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 05/26/2020] [Indexed: 05/30/2023]
Abstract
Geminiviruses contain the largest number of species of plant viruses, and cause devastating crop diseases worldwide. The development of resistance to these viruses will require a clear understanding of viral protein function and interactions. Tomato yellow leaf curl China virus (TYLCCNV) is a typical monopartite geminivirus, which is associated with a tomato yellow leaf curl China betasatellite (TYLCCNB) in the field; the complex infection of TYLCCNV/TYLCCNB leads to serious economic losses in solanaceous plants. The functions of each protein encoded by the TYLCCNV/TYLCCNB complex have not yet been examined in a targeted manner. Here, we show the dynamic subcellular localization and accumulation of six viral proteins encoded by TYLCCNV and the βC1 protein encoded by TYLCCNB in plants over time, and analyzed the effect of TYLCCNV or TYLCCNV/TYLCCNB infection on these parameters. The interaction among the seven viral proteins was also tested in this study: C2 acts as a central player in the viral protein interaction network, since it interacts with C3, C4, V2, and βC1. Self-interactions were also found for C1, C2, and V2. Together, the data presented here provide a template for investigating the function of viral proteins with or without viral infection over time, and points at C2 as a pivotal protein potentially playing a central role in the coordination of the viral life cycle.
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Affiliation(s)
- Hao Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mingzhen Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Pan Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
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16
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Luna AP, Lozano-Durán R. Geminivirus-Encoded Proteins: Not All Positional Homologs Are Made Equal. Front Microbiol 2020; 11:878. [PMID: 32431689 PMCID: PMC7214792 DOI: 10.3389/fmicb.2020.00878] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 04/15/2020] [Indexed: 01/02/2023] Open
Affiliation(s)
- Ana P. Luna
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora” (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
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17
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Superinfection by PHYVV Alters the Recovery Process in PepGMV-Infected Pepper Plants. Viruses 2020; 12:v12030286. [PMID: 32151060 PMCID: PMC7150747 DOI: 10.3390/v12030286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 01/02/2023] Open
Abstract
Geminiviruses are important plant pathogens that affect crops around the world. In some geminivirus-host interactions, infected plants show recovery, a phenomenon characterized by symptom disappearance in newly emerging leaves. In pepper-Pepper golden mosaic virus (PepGMV) interaction, the host recovery process involves a silencing mechanism that includes both post-transcriptional (PTGS) and transcriptional (TGS) gene silencing pathways. Under field conditions, PepGMV is frequently found in mixed infections with Pepper huasteco yellow vein virus (PHYVV), another bipartite begomovirus. Mixed infected plants generally show a synergetic phenomenon and do not present recovery. Little is known about the molecular mechanism of this interaction. In the present study, we explored the effect of superinfection by PHYVV on a PepGMV-infected pepper plant showing recovery. Superinfection with PHYVV led to (a) the appearance of severe symptoms, (b) an increase of the levels of PepGMV DNA accumulation, (c) a decrease of the relative methylation levels of PepGMV DNA, and (d) an increase of chromatin activation marks present in viral minichromosomes. Finally, using heterologous expression and silencing suppression reporter systems, we found that PHYVV REn presents TGS silencing suppressor activity, whereas similar experiments suggest that Rep might be involved in suppressing PTGS.
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Wang Y, Wu Y, Gong Q, Ismayil A, Yuan Y, Lian B, Jia Q, Han M, Deng H, Hong Y, Hanley-Bowdoin L, Qi Y, Liu Y. Geminiviral V2 Protein Suppresses Transcriptional Gene Silencing through Interaction with AGO4. J Virol 2019; 93:e01675-18. [PMID: 30626668 PMCID: PMC6401443 DOI: 10.1128/jvi.01675-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/18/2018] [Indexed: 12/14/2022] Open
Abstract
In plants, RNA-directed DNA methylation (RdDM)-mediated transcriptional gene silencing (TGS) is a natural antiviral defense against geminiviruses. Several geminiviral proteins have been shown to target the enzymes related to the methyl cycle or histone modification; however, it remains largely unknown whether and by which mechanism geminiviruses directly inhibit RdDM-mediated TGS. In this study, we showed that Cotton leaf curl Multan virus (CLCuMuV) V2 directly interacts with Nicotiana benthamiana AGO4 (NbAGO4) and that the L76S mutation in V2 (V2L76S) abolishes such interaction. We further showed that V2, but not V2L76S, can suppresses RdDM and TGS. Silencing of NbAGO4 inhibits TGS, reduces the viral methylation level, and enhances CLCuMuV DNA accumulation. In contrast, the V2L76S substitution mutant attenuates CLCuMuV infection and enhances the viral methylation level. These findings reveal that CLCuMuV V2 contributes to viral infection by interaction with NbAGO4 to suppress RdDM-mediated TGS in plants.IMPORTANCE In plants, the RNA-directed DNA methylation (RdDM) pathway is a natural antiviral defense mechanism against geminiviruses. However, how geminiviruses counter RdDM-mediated defense is largely unknown. Our findings reveal that Cotton leaf curl Multan virus V2 contributes to viral infection by interaction with NbAGO4 to suppress RNA-directed DNA methylation-mediated transcriptional gene silencing in plants. Our work provides the first evidence that a geminiviral protein is able to directly target core RdDM components to counter RdDM-mediated TGS antiviral defense in plants, which extends our current understanding of viral counters to host antiviral defense.
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Affiliation(s)
- Yunjing Wang
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Yuyao Wu
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Qian Gong
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Asigul Ismayil
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Yuxiang Yuan
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Bi Lian
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Qi Jia
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Meng Han
- MOE Key Laboratory of Bioinformatics and the Center of Biomedical Analysis, School of Life Sciences, Tsinghua University, Beijing, China
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics and the Center of Biomedical Analysis, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yiguo Hong
- Research Center for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Linda Hanley-Bowdoin
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Yijun Qi
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Center for Plant Biology, Tsinghua University, Beijing, China
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Rishishwar R, Dasgupta I. Suppressors of RNA silencing encoded by geminiviruses and associated DNA satellites. Virusdisease 2019; 30:58-65. [PMID: 31143832 PMCID: PMC6517462 DOI: 10.1007/s13337-018-0418-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 01/05/2018] [Indexed: 12/31/2022] Open
Abstract
In plants, RNA silencing provides a major line of defence against viruses. This antiviral immunity involves production of virus-derived small interfering RNAs (vsiRNAs) and results in specific silencing of viruses by vsiRNAs-guided effector complexes. As a counterattack against RNA silencing, many plant viruses encode suppressors of RNA silencing called viral suppressors of RNA silencing (VSRs), which interfere with the silencing pathway by various mechanisms. This review describes various methods that are being used to characterize viral proteins for suppressor function, VSRs found in geminiviruses and associated DNA satellites and their mechanisms of action.
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Affiliation(s)
- Rashmi Rishishwar
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021 India
| | - Indranil Dasgupta
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, 110021 India
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20
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Lu QY, Yang L, Huang J, Zheng L, Sun X. Identification and subcellular location of an RNA silencing suppressor encoded by mulberry crinkle leaf virus. Virology 2019; 526:45-51. [PMID: 30342301 DOI: 10.1016/j.virol.2018.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/04/2018] [Accepted: 10/04/2018] [Indexed: 11/28/2022]
Abstract
Mulberry crinkle leaf virus (MCLV) is a novel geminivirus recently identified from the woody plant mulberry (Morus alba L.). Little is known about the functions of the proteins encoded by the MCLV genome. Here, all the MCLV-encoded proteins were examined for the ability to suppress gene silencing by an agroinfiltration assay in combination with northern blot analysis of green fluorescent protein (GFP) mRNA and western blot analysis. Of the six proteins, only one protein, V3, which has been predicted to play a role in viral movement, was found to suppress the gene silencing induced by a sense GFP gene in Nicotiana benthamiana 16c. The minimal amino acid sequence of V3 that maintains suppressor activity was also determined by constructing truncated mutants lacking different lengths of the amino acid sequences at the N- or C-terminus of the V3 protein. The results showed that the 94 N-terminal amino acid residues of V3 are sufficient to maintain V3 suppressor activity. In addition, the subcellular location of the V3 protein was investigated by confocal laser scanning microscopy after the expression of a V3-RFP fused protein in leaf epidermal cells of N. benthamiana. The results indicated that the V3 protein localized not only to the cytoplasm but also to the nucleus of N. benthamiana, implying that V3 can shuttle between the nucleus and the cytoplasm. Deletion mutant analysis indicated that a putative nuclear localization signal (NLS) between aa 118-134 might be responsible for the nuclear distribution of the V3 protein. Given the importance of RNA silencing in plant-virus interactions, the identification of a silencing suppressor of MCLV should be valuable in understanding the pathogenicity and molecular biology of this virus.
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Affiliation(s)
- Quan-You Lu
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China.
| | - Lei Yang
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
| | - Jinshan Huang
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
| | - Luping Zheng
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Xin Sun
- The Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China; Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu, China
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Yang X, Ren Y, Sun S, Wang D, Zhang F, Li D, Li S, Zhou X. Identification of the Potential Virulence Factors and RNA Silencing Suppressors of Mulberry Mosaic Dwarf-Associated Geminivirus. Viruses 2018; 10:E472. [PMID: 30177616 PMCID: PMC6163789 DOI: 10.3390/v10090472] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/27/2018] [Accepted: 08/30/2018] [Indexed: 01/31/2023] Open
Abstract
Plant viruses encode virulence factors or RNA silencing suppressors to reprogram plant cellular processes or to fine-tune host RNA silencing-mediated defense responses. In a previous study, Mulberry mosaic dwarf-associated virus (MMDaV), a novel, highly divergent geminivirus, has been identified from a Chinese mulberry tree showing mosaic and dwarfing symptoms, but the functions of its encoded proteins are unknown. In this study, all seven proteins encoded by MMDaV were screened for potential virulence and RNA silencing suppressor activities. We found that V2, RepA, and Rep affect the pathogenicity of a heterologous potato virus X. We showed that V2 could inhibit local RNA silencing and long-distance movement of the RNA silencing signal, but not short-range spread of the green fluorescent protein (GFP) silencing signal in Nicotiana benthamiana 16c plants. In addition, V2 localized to both subnuclear foci and the cytoplasm. Deletion mutagenesis of V2 showed that the basic motif from amino acids 61 to 76 was crucial for V2 to form subnuclear foci and for suppression of RNA silencing. Although the V2 protein encoded by begomoviruses or a curtovirus has been shown to have silencing suppressor activity, this is the first identification of an RNA silencing suppressor from a woody plant-infecting geminivirus.
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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.
| | - Yanxiang Ren
- 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 Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
| | - Shaoshuang Sun
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Dongxue Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Fanfan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 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.
| | - 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.
| | - 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, Zhejiang, China.
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Vinutha T, Kumar G, Garg V, Canto T, Palukaitis P, Ramesh SV, Praveen S. Tomato geminivirus encoded RNAi suppressor protein, AC4 interacts with host AGO4 and precludes viral DNA methylation. Gene 2018; 678:184-195. [PMID: 30081188 DOI: 10.1016/j.gene.2018.08.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 06/12/2018] [Accepted: 08/03/2018] [Indexed: 11/18/2022]
Abstract
Plant RNA silencing systems are organized as a network, regulating plant developmental pathways and restraining invading viruses, by sharing cellular components with overlapping functions. Host regulatory networks operate either at the transcriptional level via RNA-directed DNA methylation, or at the post-transcriptional stage interfering with mRNA to restrict viral infection. However, viral-derived proteins, including suppressors of RNA silencing, favour virus establishment, and also affect plant developmental processes. In this investigation, we report that Tomato leaf curl New Delhi virus-derived AC4 protein suppresses RNA silencing activity and mutational analysis of AC4 showed that Asn-50 in the SKNT-51 motif, in the C-terminal region, is a critical determinant of its RNA silencing suppressor activity. AC4 showed interaction with host AGO4 but not with AGO1, aggregated around the nucleus, and influenced cytosine methylation of the viral genome. The possible molecular mechanism by which AC4 interferes in the RNA silencing network, helps virus establishment, and affects plant development is discussed.
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Affiliation(s)
- T Vinutha
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi 110012, India
| | - Gaurav Kumar
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi 110012, India
| | - Varsha Garg
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi 110012, India
| | - Tomas Canto
- Centro de Investigaciones Biológicas, CIB, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Seoul 01797, Republic of Korea
| | - S V Ramesh
- ICAR-Central Plantation Crops Research Institute (ICAR-CPCRI), Kasaragod, Kerala 671 124, India.
| | - Shelly Praveen
- Division of Biochemistry, ICAR-Indian Agricultural Research Institute (ICAR-IARI), New Delhi 110012, India.
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Feng M, Zuo D, Jiang X, Li S, Chen J, Jiang L, Zhou X, Jiang T. Identification of Strawberry vein banding virus encoded P6 as an RNA silencing suppressor. Virology 2018; 520:103-110. [PMID: 29843054 DOI: 10.1016/j.virol.2018.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 11/25/2022]
Abstract
RNA silencing is a common mechanism that plays a key role in antiviral defense. To overcome host defense responses, plant viruses encode silencing-suppressor proteins to target one or several key steps in the silencing machinery. Here, we report that the P6 protein encoded by Strawberry vein banding virus (SVBV) is an RNA silencing suppressor through Agrobacterium-mediated co-infiltration assays. SVBV P6 protein can suppress green fluorescent protein (GFP) gene silencing induced by single-stranded RNA but not by double-stranded RNA. The P6 protein can also inhibit systemic silencing of GFP through interfering the systemic spread of GFP silencing signal. Subcellular localization study indicated that P6 protein formed irregular bodies and distributed in both cytoplasm and nucleus of Nicotiana benthamiana cells. Furthermore, deletion analysis indicated that a nuclear localization signal (NLS, aa 402-426) in the P6 protein is responsible for the silencing suppression efficiency. In addition, expression of the P6 protein via a Potato virus X (PVX)-based vectors induced more severe mosaic symptoms in N. benthamiana leaves, and transgenic N. benthamiana plants expressing P6 showed obvious vein yellowing as well as severe mosaic symptoms in leaves. Taken together, our results demonstrates that SVBV P6 is a suppressor of RNA silencing, possibly acting at a upstream step for dsRNA generation.
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Affiliation(s)
- Mingfeng Feng
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Dengpan Zuo
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Xizi Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Shuai Li
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Jing Chen
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China
| | - Lei Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of 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, People's Republic of China
| | - Tong Jiang
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, People's Republic of China.
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Single amino acid in V2 encoded by TYLCV is responsible for its self-interaction, aggregates and pathogenicity. Sci Rep 2018; 8:3561. [PMID: 29476063 PMCID: PMC5824789 DOI: 10.1038/s41598-018-21446-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 11/20/2017] [Indexed: 11/24/2022] Open
Abstract
The V2 protein encoded by Begomovirus is essential for virus infection and is involved in multiple functions, such as virus movement and suppression of the host defence response. In this study, we reported that V2 encoded by the Tomato yellow leaf curl virus (TYLCV), which is one of the most devastating tomato-infecting begomoviruses, could interact with itself and a S71A mutation of V2 (V2S71A) abolished its self-interaction. Fluorescence results showed that V2 localized primarily in the cytoplasm and around the nucleus. Site-directed mutagenesis V2S71A had the similar subcellular localization, but V2S71A formed fewer large aggregates in the cytoplasm compared to wild-type V2, whereas the level of aggregates came to a similar after treatment with MG132, which indicates that the S71A mutation might affect 26S proteasome-mediated degradation of V2 aggregates. Meanwhile, heterologous expression of V2S71A from a Potato virus X vector induced mild symptoms compared to wild-type V2, delay of virus infection associated with mild symptoms was observed in plants inoculated with TYLCV-S71A, which indicates that the amino acid on position 71 is also involved in the pathogenicity of V2. To the best of our knowledge, this report is the first to state that the S71A mutation of V2 encoded by TYLCV affects the self-interaction, aggregate formation and pathogenicity of V2.
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Roshan P, Kulshreshtha A, Kumar S, Purohit R, Hallan V. AV2 protein of tomato leaf curl Palampur virus promotes systemic necrosis in Nicotiana benthamiana and interacts with host Catalase2. Sci Rep 2018; 8:1273. [PMID: 29352245 PMCID: PMC5775426 DOI: 10.1038/s41598-018-19292-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 12/27/2017] [Indexed: 11/08/2022] Open
Abstract
Tomato leaf curl Palampur virus (ToLCPalV) is a whitefly-transmitted, bipartite begomovirus. Here, we demonstrated that ectopic expression of AV2 from a Potato virus X (PVX)-based vector accelerated systemic necrosis and reactive oxygen species (ROS) accumulation in Nicotiana benthamiana. Furthermore, 10 amino acids from N-terminal region of AV2 were found to be associated with the systemic necrosis symptom/phenotype. Mutational studies of ToLCPalV infectious clones lacking the AV2 revealed that AV2 is essential for the systemic movement of DNA-A, symptom severity and viral DNA accumulation. In a yeast two-hybrid assay, Catalase2 (Cat2) was found to associate with AV2 protein. Further, silencing of Cat2 resulted in appearance of necrotic lesions on N. benthamiana and these plants were highly susceptible to ToLCPalV infection in comparison to control plants. Infection ToLCPalV on Solanum lycopersicum resulted in downregulation of Cat2 transcripts, followed by accumulation of ROS and stress marker transcripts. The AV2 protein also suppressed virus-induced gene silencing (VIGS) of the Phytoene desaturase (PDS) gene. Our results show that AV2 is essential for the pathogenicity, systemic movement and suppression of gene silencing in the host. Altogether, our findings suggest that interactions between AV2 and Cat2 might play a crucial role in the establishment of ToLCPalV infection.
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Affiliation(s)
- Poonam Roshan
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, HP, 176061, India
- Plant Virology Lab, CSIR-IHBT, Palampur, HP, 176061, India
| | - Aditya Kulshreshtha
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, HP, 176061, India
- Plant Virology Lab, CSIR-IHBT, Palampur, HP, 176061, India
| | - Surender Kumar
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, HP, 176061, India
- Plant Virology Lab, CSIR-IHBT, Palampur, HP, 176061, India
| | - Rituraj Purohit
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, HP, 176061, India
- Biotechnology division, CSIR-IHBT, Palampur, HP, 176061, India
| | - Vipin Hallan
- Academy of Scientific & Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, HP, 176061, India.
- Plant Virology Lab, CSIR-IHBT, Palampur, HP, 176061, India.
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Roshan P, Kulshreshtha A, Hallan V. Identification of host cellular targets of AC4 and AV2 proteins of tomato leaf curl palampur virus and their sub-cellular localization studies. Virusdisease 2017; 28:390-400. [PMID: 29291230 PMCID: PMC5747847 DOI: 10.1007/s13337-017-0405-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/05/2017] [Indexed: 01/06/2023] Open
Abstract
Tomato leaf curl palampur virus (ToLCPalV) is a bipartite begomovirus with genome organization typical of old world begomoviruses. It infects commercially important crops and weeds in the Asian subcontinent. Apart from other proteins, the DNA-A of the virus encodes AV2 and AC4 proteins of approximately 13.73 and 6.7 kDa, respectively. In case of other begomoviruses, previous studies have shown the role of AV2 and AC4 proteins in virus movement, pathogenesis and suppression of gene silencing. However, the ToLCPalV proteins are significantly variable in comparison to closest relative and hence there is a need to work out their functions. In this study, we identified 9 cellular proteins of tomato that interact with AV2 and AC4 proteins, through yeast two hybrid screening. Upon sequence analysis, these interactors were identified as cysteine protease, katanin p60 ATPase-containing subunit A-like, guanine deaminase, NADH dehydrogenase (ubiquinone) iron-sulfur protein, glyceraldehyde-3-phosphate dehydrogenase B, 60S acidic ribosomal P0 protein, acyl co-A dehydrogenase IBR3, oxygen-evolving enhancer protein 1 and peroxisomal membrane protein 11D. These proteins play a vital role in protein degradation, plant defense response, microtubule severing, photosynthesis and protein synthesis. The two viral proteins, however, did not interact with each other in yeast. AV2 when fused with GFP under the control of cauliflower mosaic virus 35S promoter was localized in nucleus and cytoplasm. On the other hand, AC4-GFP fusion was localized only in cytoplasm. The outcome of present study will help to elucidate the mechanism of viral pathogenesis. Further functional characterization of identified host proteins will provide an insight into their involvement in disease development.
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Affiliation(s)
- Poonam Roshan
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, India
- Plant Virology Lab, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, HP 176061 India
| | - Aditya Kulshreshtha
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, India
- Plant Virology Lab, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, HP 176061 India
| | - Vipin Hallan
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology (CSIR-IHBT) Campus, Palampur, India
- Plant Virology Lab, Biotechnology Division, CSIR-Institute of Himalayan Bioresource Technology, Palampur, HP 176061 India
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Luna AP, Rodríguez-Negrete EA, Morilla G, Wang L, Lozano-Durán R, Castillo AG, Bejarano ER. V2 from a curtovirus is a suppressor of post-transcriptional gene silencing. J Gen Virol 2017; 98:2607-2614. [PMID: 28933688 DOI: 10.1099/jgv.0.000933] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The suppression of gene silencing is a key mechanism for the success of viral infection in plants. DNA viruses from the Geminiviridae family encode several proteins that suppress transcriptional and post-transcriptional gene silencing (TGS/PTGS). In Begomovirus, the most abundant genus of this family, three out of six genome-encoded proteins, namely C2, C4 and V2, have been shown to suppress PTGS, with V2 being the strongest PTGS suppressor in transient assays. Beet curly top virus (BCTV), the model species for the Curtovirus genus, is able to infect the widest range of plants among geminiviruses. In this genus, only one protein, C2/L2, has been described as inhibiting PTGS. We show here that, despite the lack of sequence homology with its begomoviral counterpart, BCTV V2 acts as a potent PTGS suppressor, possibly by impairing the RDR6 (RNA-dependent RNA polymerase 6)/suppressor of gene silencing 3 (SGS3) pathway.
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Affiliation(s)
- Ana P Luna
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Edgar A Rodríguez-Negrete
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain.,Present address: Departamento de Biotecnología Agrícola, Instituto Politécnico Nacional, CIIDIR-IPN, Unidad Sinaloa, Blvd. Juan de Dios Bátiz Paredes No 250. Guasave, Sinaloa CP 81101, Mexico
| | - Gabriel Morilla
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Liping Wang
- Shanghai Center for Plant Stress Biology (PSC), Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, PR China.,University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology (PSC), Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 201602, PR China
| | - Araceli G Castillo
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
| | - Eduardo R Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' (IHSM-UMA-CSIC), Area de Genética, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, E-29071 Málaga, Spain
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Ramesh SV, Sahu PP, Prasad M, Praveen S, Pappu HR. Geminiviruses and Plant Hosts: A Closer Examination of the Molecular Arms Race. Viruses 2017; 9:E256. [PMID: 28914771 PMCID: PMC5618022 DOI: 10.3390/v9090256] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/02/2017] [Accepted: 09/06/2017] [Indexed: 11/24/2022] Open
Abstract
Geminiviruses are plant-infecting viruses characterized by a single-stranded DNA (ssDNA) genome. Geminivirus-derived proteins are multifunctional and effective regulators in modulating the host cellular processes resulting in successful infection. Virus-host interactions result in changes in host gene expression patterns, reprogram plant signaling controls, disrupt central cellular metabolic pathways, impair plant's defense system, and effectively evade RNA silencing response leading to host susceptibility. This review summarizes what is known about the cellular processes in the continuing tug of war between geminiviruses and their plant hosts at the molecular level. In addition, implications for engineered resistance to geminivirus infection in the context of a greater understanding of the molecular processes are also discussed. Finally, the prospect of employing geminivirus-based vectors in plant genome engineering and the emergence of powerful genome editing tools to confer geminivirus resistance are highlighted to complete the perspective on geminivirus-plant molecular interactions.
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Affiliation(s)
- Shunmugiah V Ramesh
- ICAR-Indian Institute of Soybean Research, Indian Council of Agricultural Research, Indore 452001, India.
- Department of Plant Pathology, Washington State University, Pullman, WA 99163, USA.
| | - Pranav P Sahu
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi110067, India.
| | - Manoj Prasad
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi110067, India.
| | - Shelly Praveen
- Division of Plant Pathology, Advanced Centre for Plant Virology, ICAR-Indian Agricultural Research Institute (IARI), New Delhi 110012, India.
| | - Hanu R Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA 99163, USA.
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29
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Kuria P, Ilyas M, Ateka E, Miano D, Onguso J, Carrington JC, Taylor NJ. Differential response of cassava genotypes to infection by cassava mosaic geminiviruses. Virus Res 2016; 227:69-81. [PMID: 27693919 PMCID: PMC5130204 DOI: 10.1016/j.virusres.2016.09.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/26/2016] [Accepted: 09/29/2016] [Indexed: 12/21/2022]
Abstract
Cassava genotypes respond differently to infection by cassava mosaic geminiviruses. Cassava mosaic disease resistant loci prompt recovery from systemic infection. CMD symptoms are directly correlated with contents of viral DNA and virus specific small RNAs. CMD infected plants abundantly accumulate 21–24 nt of virus specific small RNAs. VsRNAs heterogeneously map the entire virus genome in both polarities.
Mitigation of cassava mosaic disease (CMD) focuses on the introgression of resistance imparted by the polygenic recessive (CMD1), dominant monogenic (CMD2) and CMD3 loci. The mechanism(s) of resistance they impart, however, remain unknown. Two CMD susceptible and nine CMD resistant cassava genotypes were inoculated by microparticle bombardment with infectious clones of African cassava mosaic virus Cameroon strain (ACMV-CM) and the Kenyan strain K201 of East African cassava mosaic virus (EACMV KE2 [K201]). Genotypes carrying the CMD1 (TMS 30572), CMD2 (TME 3, TME 204 and Oko-iyawo) and CMD3 (TMS 97/0505) resistance mechanisms showed high levels of resistance to ACMV-CM, with viral DNA undetectable by PCR beyond 7 days post inoculation (dpi). In contrast, all genotypes initially developed severe CMD symptoms and accumulated high virus titers after inoculation with EACMV KE2 (K201). Resistant genotypes recovered to become asymptomatic by 65 dpi with no detectable virus in newly formed leaves. Genotype TMS 97/2205 showed highest resistance to EACMV KE2 (K201) with <30% of inoculated plants developing symptoms followed by complete recovery by 35 dpi. Deep sequencing of small RNAs confirmed production of 21–24 nt virus derived small RNAs (vsRNA) that mapped to cover the entire ACMV-CM and EACMV KE2 (K201) viral genomes in both polarities, with hotspots seen within gene coding regions. In resistant genotypes, total vsRNAs were most abundant at 20 and 35 dpi but reduced significantly upon recovery from CMD. In contrast, CMD susceptible genotypes displayed abundant vsRNAs throughout the experimental period. The percentage of vsRNAs reads ranked by class size were 21nt (45%), 22 nt (28%) and 24 nt (18%) in all genotypes studied. The number of vsRNA reads directly correlated with virus titer and CMD symptoms.
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Affiliation(s)
- Paul Kuria
- Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200 Nairobi, Kenya; Kenya Agricultural and Livestock Research Organization, PO Box 57811-00200, Nairobi, Kenya
| | - Muhammad Ilyas
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Elijah Ateka
- Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200 Nairobi, Kenya
| | - Douglas Miano
- University of Nairobi, PO BOX 30197, 00100, Nairobi, Kenya
| | - Justus Onguso
- Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200 Nairobi, Kenya
| | - James C Carrington
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA
| | - Nigel J Taylor
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO, 63132, USA.
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30
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Jailani AAK, Kumar A, Mandal B, Sivasudha T, Roy A. Agroinfection of tobacco by croton yellow vein mosaic virus and designing of a replicon vector for expression of foreign gene in plant. Virusdisease 2016; 27:277-286. [PMID: 28466040 PMCID: PMC5394710 DOI: 10.1007/s13337-016-0326-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 06/14/2016] [Indexed: 01/18/2023] Open
Abstract
Croton yellow vein mosaic virus (CYVMV, genus Begomovirus family Geminiviridae) is a proliferating begomovirus in the Indian sub-continent. The infectious constructs in binary vector was developed against the CYVMV genome and its associated betasatellite. Agroinoculation of the genomic construct of CYVMV produced leaf curl symptoms alone in three species of tobacco, Nicotiana tabacum, N. benthamiana and N. glutinosa. Co-inoculation of betasatellite enhanced the severity of the disease and reduced the incubation time. Based on the infectious clone, a replicon vector pCro, with only the ability to replicate inside the plant was developed. In pCro vector, CP and V2 ORFs from genome of CYVMV was deleted, which resulted localised replication of the molecule with no visible symptoms. Besides the partial CYVMV genome, pCro also has a cassette containing a double 35S promoter, multiple cloning sites and a NOS terminator to overexpress any foreign protein in plant. Episomal release of the replicon from the binary vector backbone after agroinoculation was detected by PCR. A GFP gene was cloned in pCro vector (pCro-GFP) and agroinoculated to N. tabacum resulted in localized expression of GFP at 5 dpi. The CYVMV replicon vector will be a useful tool for studying functional genomics, vaccine expression and gene silencing in plant.
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Affiliation(s)
- A. Abdul Kader Jailani
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012 India
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, 620 024 Tamil Nadu India
| | - Alok Kumar
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Bikash Mandal
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012 India
| | - T. Sivasudha
- Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli, 620 024 Tamil Nadu India
| | - Anirban Roy
- Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012 India
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Huang Y, Ma HY, Huang W, Wang F, Xu ZS, Xiong AS. Comparative proteomic analysis provides novel insight into the interaction between resistant vs susceptible tomato cultivars and TYLCV infection. BMC PLANT BIOLOGY 2016; 16:162. [PMID: 27436092 PMCID: PMC4952150 DOI: 10.1186/s12870-016-0819-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 05/24/2016] [Indexed: 05/18/2023]
Abstract
BACKGROUND Tomato yellow leaf curl virus (TYLCV) is a member of the family Geminiviridae, genus Begomovirus. The virus is a widespread plant virus that causes important economic losses in tomatoes. Genetic engineering strategies have increasingly been adopted to improve the resistance of tomatoes to TYLCV. RESULTS In this study, a proteomic approach was used to investigate the molecular mechanisms involved in tomato leaf defense against TYLCV infection. Proteins extracted from leaves of resistant tomato cultivar 'Zheza-301' and susceptible cultivar 'Jinpeng-1' after TYLCV infection were analyzed using two-dimensional gel electrophoresis. Eighty-six differentially expressed proteins were identified and classified into seven groups based on their functions. For several of the proteins, including CDC48, CHI and HSC70, expression patterns measured using quantitative real-time PCR differed from the results of the proteomic analysis. A putative interaction network between tomato leaves and TYLCV infection provides us with important information about the cellular activities that are involved in the response to TYLCV infection. CONCLUSIONS We conducted a comparative proteomic study of TYLCV infection in resistant and susceptible tomato cultivars. The proteins identified in our work show a variety of functions and expression patterns in the process of tomato-TYLCV interaction, and these results contribute to our understanding of the mechanism underlying TYLCV resistance in tomatoes at the protein level.
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Affiliation(s)
- Ying Huang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, Jiangsu, China
| | - Hong-Yu Ma
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Wei Huang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, Jiangsu, China
| | - Feng Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, Jiangsu, China
| | - Zhi-Sheng Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, Jiangsu, China
| | - Ai-Sheng Xiong
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, Jiangsu, China.
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Analysis of the Mild strain of tomato yellow leaf curl virus, which overcomes Ty-2 gene-mediated resistance in tomato line H24. Arch Virol 2016; 161:2207-17. [PMID: 27231006 DOI: 10.1007/s00705-016-2898-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/16/2016] [Indexed: 10/21/2022]
Abstract
In tomato line H24, an isolate of the Mild (Mld) strain of tomato yellow leaf curl virus (TYLCV-Mld [JR:Kis]) overcomes Ty-2 gene-mediated resistance and causes typical symptoms of tomato yellow leaf curl disease (TYLCD). No systemic infection with visible symptoms or accumulation of viral DNA in the upper leaves was observed in H24 challenged with another isolate, TYLCV-IL (TYLCV-IL [JR:Osaka]), confirming that H24 is resistant to the IL strain. To elucidate the genomic regions that cause the breakdown of the Ty-2 gene-mediated resistance, we constructed a series of chimeras by swapping genes between the two strains. A chimeric virus that had the overlapping C4/Rep region of the Mld strain in the context of the IL strain genome, caused severe TYLCD in H24 plants, suggesting that the overlapping C4/Rep region of the Mld strain is associated with the ability of this strain to overcome Ty-2 gene-mediated resistance.
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33
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Matić S, Pegoraro M, Noris E. The C2 protein of tomato yellow leaf curl Sardinia virus acts as a pathogenicity determinant and a 16-amino acid domain is responsible for inducing a hypersensitive response in plants. Virus Res 2016; 215:12-9. [PMID: 26826600 DOI: 10.1016/j.virusres.2016.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/13/2016] [Accepted: 01/21/2016] [Indexed: 11/25/2022]
Abstract
The role of the C2 protein in the pathogenicity of tomato yellow leaf curl Sardinia virus (TYLCSV) was investigated. Here we report that Agrobacterium-mediated transient expression of TYLCSV C2 resulted in a strong hypersensitive response (HR) in Nicotiana benthamiana, N. tabacum, and Arabidopsis thaliana, with induction of plant cell death and production of H2O2. Since HR is not evident in plants infected by TYLCSV, it is expected that TYLCSV encodes a gene (or genes) that counters this response. HR was partially counteracted by co-agroinfiltration of TYLCSV V2 and Rep, leading to chlorotic reaction, with no HR development. Considering that the corresponding C2 protein of the closely related tomato yellow leaf curl virus (TYLCV) did not induce HR, alignment of the C2 proteins of TYLCSV and TYLCV were carried out and a hypervariable region of 16 amino acids was identified. Its role in the induction of HR was demonstrated using TYLCSV-TYLCV C2 chimeric genes, encoding two TYLCSV C2 variants with a complete (16 aa) or a partial (10 aa only) swap of the corresponding sequence of TYLCV C2. Furthermore, using NahG transgenic N. benthamiana lines compromised in the accumulation of salicylic acid (SA), a key regulator of HR, only a chlorotic response occurred in TYLCSV C2-infiltrated tissue, indicating that SA participates in such plant defense process. These findings demonstrate that TYLCSV C2 acts as a pathogenicity determinant and induces host defense responses controlled by the SA pathway.
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Affiliation(s)
- Slavica Matić
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - Mattia Pegoraro
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - Emanuela Noris
- Institute for Sustainable Plant Protection, CNR, Strada delle Cacce 73, 10135 Torino, Italy.
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Moshe A, Gorovits R, Liu Y, Czosnek H. Tomato plant cell death induced by inhibition of HSP90 is alleviated by Tomato yellow leaf curl virus infection. MOLECULAR PLANT PATHOLOGY 2016; 17:247-60. [PMID: 25962748 PMCID: PMC6638530 DOI: 10.1111/mpp.12275] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To ensure a successful long-term infection cycle, begomoviruses must restrain their destructive effect on host cells and prevent drastic plant responses, at least in the early stages of infection. The monopartite begomovirus Tomato yellow leaf curl virus (TYLCV) does not induce a hypersensitive response and cell death on whitefly-mediated infection of virus-susceptible tomato plants until diseased tomatoes become senescent. The way in which begomoviruses evade plant defences and interfere with cell death pathways is still poorly understood. We show that the chaperone HSP90 (heat shock protein 90) and its co-chaperone SGT1 (suppressor of the G2 allele of Skp1) are involved in the establishment of TYLCV infection. Inactivation of HSP90, as well as silencing of the Hsp90 and Sgt1 genes, leads to the accumulation of damaged ubiquitinated proteins and to a cell death phenotype. These effects are relieved under TYLCV infection. HSP90-dependent inactivation of 26S proteasome degradation and the transcriptional activation of the heat shock transcription factors HsfA2 and HsfB1 and of the downstream genes Hsp17 and Apx1/2 are suppressed in TYLCV-infected tomatoes. Following suppression of the plant stress response, TYLCV can replicate and accumulate in a permissive environment.
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Affiliation(s)
- Adi Moshe
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Rena Gorovits
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Yule Liu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Henryk Czosnek
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, 76100, Israel
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Saeed M, Briddon RW, Dalakouras A, Krczal G, Wassenegger M. Functional Analysis of Cotton Leaf Curl Kokhran Virus/Cotton Leaf Curl Multan Betasatellite RNA Silencing Suppressors. BIOLOGY 2015; 4:697-714. [PMID: 26512705 PMCID: PMC4690014 DOI: 10.3390/biology4040697] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/13/2022]
Abstract
In South Asia, Cotton leaf curl disease (CLCuD) is caused by a complex of phylogenetically-related begomovirus species and a specific betasatellite, Cotton leaf curl Multan betasatellite (CLCuMuB). The post-transcriptional gene silencing (PTGS) suppression activities of the transcriptional activator protein (TrAP), C4, V2 and βC1 proteins encoded by Cotton leaf curl Kokhran virus (CLCuKoV)/CLCuMuB were assessed in Nicotiana benthamiana. A variable degree of local silencing suppression was observed for each viral protein tested, with V2 protein exhibiting the strongest suppression activity and only the C4 protein preventing the spread of systemic silencing. The CLCuKoV-encoded TrAP, C4, V2 and CLCuMuB-encoded βC1 proteins were expressed in Escherichia coli and purified. TrAP was shown to bind various small and long nucleic acids including single-stranded (ss) and double-stranded (ds) RNA and DNA molecules. C4, V2, and βC1 bound ssDNA and dsDNA with varying affinities. Transgenic expression of C4 under the constitutive 35S Cauliflower mosaic virus promoter and βC1 under a dexamethasone inducible promoter induced severe developmental abnormalities in N. benthamiana. The results indicate that homologous proteins from even quite closely related begomoviruses may differ in their suppressor activity and mechanism of action. The significance of these findings is discussed.
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Affiliation(s)
- Muhammad Saeed
- RLP AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, Neustadt D-67435, Germany.
- National Institute for Biotechnology and Genetic Engineering, Jhang Road, PO Box 577, Faisalabad 38000, Pakistan.
| | - Rob W Briddon
- National Institute for Biotechnology and Genetic Engineering, Jhang Road, PO Box 577, Faisalabad 38000, Pakistan.
| | - Athanasios Dalakouras
- RLP AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, Neustadt D-67435, Germany.
| | - Gabi Krczal
- RLP AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, Neustadt D-67435, Germany.
| | - Michael Wassenegger
- RLP AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, Neustadt D-67435, Germany.
- Centre for Organismal Studies (COS) Heidelberg, University of Heidelberg, Im Neuenheimer Feld 360, Heidelberg D-69120, Germany.
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Csorba T, Kontra L, Burgyán J. viral silencing suppressors: Tools forged to fine-tune host-pathogen coexistence. Virology 2015; 479-480:85-103. [DOI: 10.1016/j.virol.2015.02.028] [Citation(s) in RCA: 368] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/31/2015] [Accepted: 02/16/2015] [Indexed: 12/27/2022]
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Bar-Ziv A, Levy Y, Citovsky V, Gafni Y. The Tomato yellow leaf curl virus (TYLCV) V2 protein inhibits enzymatic activity of the host papain-like cysteine protease CYP1. Biochem Biophys Res Commun 2015; 460:525-9. [PMID: 25797621 DOI: 10.1016/j.bbrc.2015.03.063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 03/11/2015] [Indexed: 01/26/2023]
Abstract
The viral V2 protein is one of the key factors that Tomato yellow leaf curl geminivirus (TYLCV), a major tomato pathogen worldwide, utilizes to combat the host defense. Besides suppressing the plant RNA silencing defense by targeting the host SGS3 component of the silencing machinery, V2 also interacts with the host CYP1 protein, a papain-like cysteine protease likely involved in hypersensitive response reactions. The biological effects of the V2-CYP1 interaction, however, remain unknown. We addressed this question by demonstrating that V2 inhibits the enzymatic activity of CYP1, but does not interfere with post-translational maturation of this protein.
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Affiliation(s)
- Amalia Bar-Ziv
- Institute of Plant Sciences, A.R.O., The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - Yael Levy
- Institute of Plant Sciences, A.R.O., The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
| | - Vitaly Citovsky
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, New York, USA
| | - Yedidya Gafni
- Institute of Plant Sciences, A.R.O., The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.
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Dey KK, Borth WB, Melzer MJ, Wang ML, Hu JS. Analysis of pineapple mealybug wilt associated virus -1 and -2 for potential RNA silencing suppressors and pathogenicity factors. Viruses 2015; 7:969-95. [PMID: 25751306 PMCID: PMC4379557 DOI: 10.3390/v7030969] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/05/2015] [Accepted: 02/15/2015] [Indexed: 01/02/2023] Open
Abstract
Higher plants use RNA silencing to defend against viral infections. As a counter defense, plant viruses have evolved proteins that suppress RNA silencing. Mealybug wilt of pineapple (MWP), an important disease of pineapple, has been associated with at least three distinct viruses, Pineapple mealybug wilt associated virus -1, -2, and -3 (PMWaV-1, -2, and -3). Selected open reading frames (ORFs) of PMWaV-1 and PMWaV-2 were screened for their local and systemic suppressor activities in Agrobacterium-mediated transient assays using green fluorescent protein (GFP) in Nicotiana benthamiana. Results indicate that PMWaV-2 utilizes a multiple-component RNA silencing suppression mechanism. Two proteins, p20 and CP, target both local and systemic silencing in N. benthamiana, while the p22 and CPd proteins target only systemic silencing. In the related virus PMWaV-1, we found that only one of the encoded proteins, p61, had only systemic suppressor activity. Of all the proteins tested from both viruses, only the PMWaV-2 p20 protein suppressed local silencing induced by double-stranded RNA (dsRNA), but only when low levels of inducing dsRNA were used. None of the proteins analyzed could interfere with the short distance spread of silencing. We examined the mechanism of systemic suppression activity by investigating the effect of PMWaV-2-encoded p20 and CP proteins on secondary siRNAs. Our results suggest that the PMWaV-2 p20 and CP proteins block the systemic silencing signal by repressing production of secondary siRNAs. We also demonstrate that the PMWaV-2 p20 and p22 proteins enhanced the pathogenicity of Potato virus X in N. benthamiana.
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Affiliation(s)
- Kishore K Dey
- Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI 96822, USA.
| | - Wayne B Borth
- Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI 96822, USA.
| | - Michael J Melzer
- Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI 96822, USA.
| | - Ming-Li Wang
- Hawaii Agricultural Research Center, Kunia, Honolulu, HI 96797, USA.
| | - John S Hu
- Department of Plant and Environmental Protection Sciences, University of Hawaii, 3190 Maile Way, Honolulu, HI 96822, USA.
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Ammara UE, Mansoor S, Saeed M, Amin I, Briddon RW, Al-Sadi AM. RNA interference-based resistance in transgenic tomato plants against Tomato yellow leaf curl virus-Oman (TYLCV-OM) and its associated betasatellite. Virol J 2015; 12:38. [PMID: 25890080 PMCID: PMC4359554 DOI: 10.1186/s12985-015-0263-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 02/10/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tomato yellow leaf curl virus (TYLCV), a monopartite begomovirus (family Geminiviridae) is responsible for heavy yield losses for tomato production around the globe. In Oman at least five distinct begomoviruses cause disease in tomato, including TYLCV. Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite). RNA interference (RNAi) can be used to develop resistance against begomoviruses at either the transcriptional or post-transcriptional levels. RESULTS A hairpin RNAi (hpRNAi) construct to express double-stranded RNA homologous to sequences of the intergenic region, coat protein gene, V2 gene and replication-associated gene of Tomato yellow leaf curl virus-Oman (TYLCV-OM) was produced. Initially, transient expression of the hpRNAi construct at the site of virus inoculation was shown to reduce the number of plants developing symptoms when inoculated with either TYLCV-OM or TYLCV-OM with ToLCB-OM to Nicotiana benthamiana or tomato. Solanum lycopersicum L. cv. Pusa Ruby was transformed with the hpRNAi construct and nine confirmed transgenic lines were obtained and challenged with TYLCV-OM and ToLCB-OM by Agrobacterium-mediated inoculation. For all but one line, for which all plants remained symptomless, inoculation with TYLCV-OM led to a proportion (≤25%) of tomato plants developing symptoms of infection. For inoculation with TYLCV-OM and ToLCB-OM all lines showed a proportion of plants (≤45%) symptomatic. However, for all infected transgenic plants the symptoms were milder and virus titre in plants was lower than in infected non-transgenic tomato plants. CONCLUSIONS These results show that RNAi can be used to develop resistance against geminiviruses in tomato. The resistance in this case is not immunity but does reduce the severity of infections and virus titer. Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.
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Affiliation(s)
- Um e Ammara
- Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman.
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Muhammad Saeed
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Imran Amin
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Rob W Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), P O Box 577, Jhang Road, Faisalabad, Pakistan.
| | - Abdullah Mohammed Al-Sadi
- Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman.
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Hak H, Levy Y, Chandran SA, Belausov E, Loyter A, Lapidot M, Gafni Y. TYLCV-Is movement in planta does not require V2 protein. Virology 2015; 477:56-60. [PMID: 25644513 DOI: 10.1016/j.virol.2015.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 12/21/2014] [Accepted: 01/05/2015] [Indexed: 11/30/2022]
Abstract
Tomato yellow leaf curl virus (TYLCV), a major tomato pathogen causing extensive crop losses, is a whitefly-transmitted geminivirus. V2 mutants of TYLCV-Is and related viruses tend to induce symptomless infection with attenuated viral DNA levels, while accumulating close to wild-type DNA levels in protoplasts, suggesting V2 as a movement protein. The discovery of plant-silencing mechanisms and viral silencing suppressors, V2 included, led us to reconsider V2׳s involvement in viral movement. We studied two mutant versions of the virus, one impaired in V2 silencing-suppression activity, and another carrying a non-translatable V2. While both mutant viruses spread in the infected plant to newly emerged leaves at the same rate as the wild-type virus, their DNA-accumulation levels were tenfold lower than in the wild-type virus. Thus, we suggest that the setback in virus proliferation, previously ascribed to a movement impediment, is due to lack of silencing-suppression activity.
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Affiliation(s)
- Hagit Hak
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel; Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | - Yael Levy
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Sam A Chandran
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Eduard Belausov
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Abraham Loyter
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | - Moshe Lapidot
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Yedidya Gafni
- Institute of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel.
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Aguilar E, Almendral D, Allende L, Pacheco R, Chung BN, Canto T, Tenllado F. The P25 protein of potato virus X (PVX) is the main pathogenicity determinant responsible for systemic necrosis in PVX-associated synergisms. J Virol 2015; 89:2090-103. [PMID: 25473046 PMCID: PMC4338884 DOI: 10.1128/jvi.02896-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 11/24/2014] [Indexed: 01/08/2023] Open
Abstract
UNLABELLED Most plant viruses counter the RNA silencing-based antiviral defense by expressing viral suppressors of RNA silencing (VSRs). In this sense, VSRs may be regarded as virulence effectors that can be recognized by the host as avirulence (avr) factors to induce R-mediated resistance. We made use of Agrobacterium-mediated transient coexpression of VSRs in combination with Potato virus X (PVX) to recapitulate in local tissues the systemic necrosis (SN) caused by PVX-potyvirus synergistic infections in Nicotiana benthamiana. The hypersensitive response (HR)-like response was associated with an enhanced accumulation of PVX subgenomic RNAs. We further show that expression of P25, the VSR of PVX, in the presence of VSR from different viruses elicited an HR-like response in Nicotiana spp. Furthermore, the expression of P25 by a Plum pox virus (PPV) vector was sufficient to induce an increase of PPV pathogenicity that led to necrotic mottling. A frameshift mutation in the P25 open reading frame (ORF) of PVX did not lead to necrosis when coexpressed with VSRs. These findings indicate that P25 is the main PVX determinant involved in eliciting a systemic HR-like response in PVX-associated synergisms. Moreover, we show that silencing of SGT1 and RAR1 attenuated cell death in both PVX-potyvirus synergistic infection and the HR-like response elicited by P25. Our study underscores that P25 variants that have impaired ability to suppress RNA silencing cannot act as elicitors when synergized by the presence of other VSRs. These findings highlight the importance of RNA silencing suppression activity in the HR-like response elicited by VSRs in certain hosts. IMPORTANCE The work presented here describes how the activity of the PVX suppressor P25 elicits an HR-like response in Nicotiana spp. when overexpressed with other VSR proteins. This finding suggests that the SN response caused by PVX-associated synergisms is a delayed immune response triggered by P25, once it reaches a threshold level by the action of other VSRs. Moreover, this work supports the contention that the silencing suppressor activity of PVX P25 protein is a prerequisite for HR elicitation. We propose that unidentified avr determinants could be involved in other cases of viral synergisms in which heterologous "helper" viruses encoding strong VSRs exacerbate the accumulation of the avr-encoding virus.
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Affiliation(s)
- Emmanuel Aguilar
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - David Almendral
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Lucía Allende
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Remedios Pacheco
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Bong Nam Chung
- National Institute of Horticultural & Herbal Science, Agricultural Research Center for Climate Change, Jeju Island, Republic of Korea
| | - Tomás Canto
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Francisco Tenllado
- Departamento de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
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Wieczorek P, Obrępalska-Stęplowska A. Suppress to Survive-Implication of Plant Viruses in PTGS. PLANT MOLECULAR BIOLOGY REPORTER 2015; 33:335-346. [PMID: 25999662 PMCID: PMC4432016 DOI: 10.1007/s11105-014-0755-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In higher plants, evolutionarily conserved processes playing an essential role during gene expression rely on small noncoding RNA molecules (sRNA). Within a wide range of sRNA-dependent cellular events, there is posttranscriptional gene silencing, the process that is activated in response to the presence of double-stranded RNAs (dsRNAs) in planta. The sequence-specific mechanism of silencing is based on RNase-mediated trimming of dsRNAs into translationally inactive short molecules. Viruses invading and replicating in host are also a source of dsRNAs and are recognized as such by cellular posttranscriptional silencing machinery leading to degradation of the pathogenic RNA. However, viruses are not totally defenseless. In parallel with evolving plant defense strategies, viruses have managed a wide range of multifunctional proteins that efficiently impede the posttranscriptional gene silencing. These viral counteracting factors are known as suppressors of RNA silencing. The aim of this review is to summarize the role and the mode of action of several functionally characterized RNA silencing suppressors encoded by RNA viruses directly involved in plant-pathogen interactions. Additionally, we point out that the widely diverse functions, structures, and modes of action of viral suppressors can be performed by different proteins, even in related viruses. All those adaptations have been evolved to achieve the same goal: to maximize the rate of viral genetic material replication by interrupting the evolutionary conserved plant defense mechanism of posttranscriptional gene silencing.
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Affiliation(s)
- Przemysław Wieczorek
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, 20 Władysława Węgorka St, 60-318 Poznań, Poland
| | - Aleksandra Obrępalska-Stęplowska
- Interdepartmental Laboratory of Molecular Biology, Institute of Plant Protection-National Research Institute, 20 Władysława Węgorka St, 60-318 Poznań, Poland
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Wang Y, Dang M, Hou H, Mei Y, Qian Y, Zhou X. Identification of an RNA silencing suppressor encoded by a mastrevirus. J Gen Virol 2014; 95:2082-2088. [PMID: 24866851 DOI: 10.1099/vir.0.064246-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Wheat dwarf virus (WDV) is a DNA virus belonging to the genus Mastrevirus of the family Geminiviridae. In this study, we report that the Rep protein encoded by WDV is a RNA silencing supressor as determined by co-infiltration assays using transgenic Nicotiana benthamiana line 16c carrying the GFP reporter gene. The Rep protein was shown to inhibit both local and systemic RNA silencing of the GFP gene as well as the spread of systemic GFP RNA silencing signals. Gel mobility shift assays showed that the Rep protein binds 21 nt and 24 nt small interfering RNA (siRNA) duplexes and single-stranded (ss)-siRNA. To our knowledge, this is the first identification of an RNA silencing suppressor encoded by mastreviruses. Furthermore, deletion mutagenesis indicates that both the N- and C-terminal regions of the Rep protein are not critical for silencing suppression and self-interaction, but the N terminus of Rep is necessary for its pathogenicity.
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Affiliation(s)
- Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Mingqing Dang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Huwei Hou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Yuzhen Mei
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
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Wang B, Li F, Huang C, Yang X, Qian Y, Xie Y, Zhou X. V2 of tomato yellow leaf curl virus can suppress methylation-mediated transcriptional gene silencing in plants. J Gen Virol 2014; 95:225-230. [PMID: 24187017 DOI: 10.1099/vir.0.055798-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tomato yellow leaf curl virus (TYLCV) is a DNA virus belonging to the genus Begomovirus. TYLCV replicates using double-stranded DNA intermediates that can become the target of plant transcriptional gene silencing (TGS). Here, we show that the V2 protein of TYLCV can suppress TGS of a transcriptionally silenced green fluorescent protein (GFP) transgene in Nicotiana benthamiana line 16-TGS. Through bisulfite sequencing and chop-PCR, we demonstrated that the TYLCV V2 can reverse GFP transgene silencing by reducing the methylation levels in the 35S promoter sequence. Both AtSN1 and MEA-ISR loci in Arabidopsis thaliana were previously reported to be strongly methylated, and we show that the methylation status of both loci was significantly reduced in TYLCV V2 transgenic Arabidopsis plants. We conclude that TYLCV can efficiently suppress TGS when it infects plants, and its V2 protein is responsible for the TGS suppression activity.
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Affiliation(s)
- Bi Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Fangfang Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Changjun Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Xiuling Yang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Yajuan Qian
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China
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Ali-Shtayeh MS, Jamous RM, Hussein EY, Mallah OB, Abu-Zeitoun SY. Squash leaf curl virus (SLCV): a serious disease threatening cucurbits production in Palestine. Virus Genes 2013; 48:320-8. [PMID: 24258392 DOI: 10.1007/s11262-013-1012-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 11/08/2013] [Indexed: 11/29/2022]
Abstract
The incidence of squash leaf curl disease and molecular characterization of the Palestinian isolate of Squash leaf curl virus [SLCV-(PAL)] are described in this study. Symptomatic leaf samples obtained from squash (Cucurbita pepo), watermelon [Citrullus lanatus (Thunb.)], and cucumber (Cucumis sativus L.) plants were tested for SLCV-[PAL] infection by PCR and RCA. SLCV was also found to occur naturally in Chenopodium murale, Convolvulus sp, and Prosporis farcta which showed yellowing. The disease incidence was 85 % in samples collected from Nablus in summer season, while it was 98 % in samples collected from Qalqilia in autumn. On the other hand, SLCV incidence did not exceed 25 % in winter season. The full-length DNA-A and DNA-B genomes of SLCV-[PAL] were amplified and sequenced, and the sequences were deposited in the GenBank. Sequence analysis reveals that SLCV-[PAL] is closely related to other isolates from Lebanon (SLCV-LB2), Jordan (SLCV-JO), Israel (SLCV-IL), and Egypt (SLCV-EG). DNA-A of SLCV-[PAL] showed the highest nucleotide identity (99.4 %) with SLCV-JO, and SLCV-LB2, while DNA-B had the highest nucleotide identity (99.3 %) with SLCV-IL. However, following genome sequencing, it was found that due to two separate point mutations, two viral open reading frames (ORF) were altered in some SLCV Palestinian isolates. The AC2 ORF was extended by 141 nucleotides, while the AC4 ORF was extended by 36 nucleotides.
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Affiliation(s)
- M S Ali-Shtayeh
- Biodiversity & Biotechnology Research Unit, Biodiversity and Environmental Research Center-BERC, Til, Nablus, Palestine,
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Hanley-Bowdoin L, Bejarano ER, Robertson D, Mansoor S. Geminiviruses: masters at redirecting and reprogramming plant processes. Nat Rev Microbiol 2013; 11:777-88. [DOI: 10.1038/nrmicro3117] [Citation(s) in RCA: 484] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Luna AP, Morilla G, Voinnet O, Bejarano ER. Functional analysis of gene-silencing suppressors from tomato yellow leaf curl disease viruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:1294-306. [PMID: 22712505 DOI: 10.1094/mpmi-04-12-0094-r] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Tomato yellow leaf curl disease (TYLCD) is caused by a complex of phylogenetically related Begomovirus spp. that produce similar symptoms when they infect tomato plants but have different host ranges. In this work, we have evaluated the gene-silencing-suppression activity of C2, C4, and V2 viral proteins isolated from the four main TYLCD-causing strains in Spain in Nicotiana benthamiana. We observed varying degrees of local silencing suppression for each viral protein tested, with V2 proteins from all four viruses exhibiting the strongest suppression activity. None of the suppressors were able to avoid the spread of the systemic silencing, although most produced a delay. In order to test the silencing-suppression activity of Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV) proteins in a shared (tomato) and nonshared (bean) host, we established novel patch assays. Using these tools, we found that viral proteins from TYLCV were able to suppress silencing in both hosts, whereas TYLCSV proteins were only effective in tomato. This is the first time that viral suppressors from a complex of disease-causing geminiviruses have been subject to a comprehensive analysis using two economically important crop hosts, as well as the established N. benthamiana plant model.
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Affiliation(s)
- Ana P Luna
- Departamento de Genetica, Universidad de Malaga, Malaga, Spain
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Bar-Ziv A, Levy Y, Hak H, Mett A, Belausov E, Citovsky V, Gafni Y. The tomato yellow leaf curl virus (TYLCV) V2 protein interacts with the host papain-like cysteine protease CYP1. PLANT SIGNALING & BEHAVIOR 2012; 7:983-9. [PMID: 22827939 PMCID: PMC3474700 DOI: 10.4161/psb.20935] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The V2 protein of Tomato yellow leaf curl geminivirus (TYLCV) is an RNA-silencing suppressor that counteracts the innate immune response of the host plant. However, this anti-host defense function of V2 may include targeting of other defensive mechanisms of the plant. Specifically, we show that V2 recognizes and directly binds the tomato CYP1 protein, a member of the family of papain-like cysteine proteases which are involved in plant defense against diverse pathogens. This binding occurred both in vitro and in vivo, within living plant cells. The V2 binding site within mCYP1 was identified in the direct proximity to the papain-like cysteine protease active site.
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Affiliation(s)
- Amalia Bar-Ziv
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan, Israel
| | - Yael Levy
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
| | - Hagit Hak
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
- Department of Biological Chemistry; The Alexander Silberman Institute of Life Sciences; The Hebrew University of Jerusalem; Jerusalem, Israel
| | - Anahit Mett
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
| | - Eduard Belausov
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
| | - Vitaly Citovsky
- Department of Biochemistry and Cell Biology; State University of New York; Stony Brook, NY USA
| | - Yedidya Gafni
- Institute of Plant Sciences; A.R.O.; The Volcani Center; Bet Dagan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan, Israel
- Correspondence to: Yedidya Gafni;
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