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Ma X, Zhou Y, Wu L, Moffett P. Resistance gene Ty-1 restricts TYLCV infection in tomato by increasing RNA silencing. Virol J 2024; 21:256. [PMID: 39415211 PMCID: PMC11483987 DOI: 10.1186/s12985-024-02508-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Accepted: 09/18/2024] [Indexed: 10/18/2024] Open
Abstract
A major antiviral mechanism in plants is mediated by RNA silencing through the action of DICER-like (DCL) proteins, which cleave dsRNA into discrete small RNA fragments, and ARGONAUTE (AGO) proteins, which use the small RNAs to target single-stranded RNA. RNA silencing can also be amplified through the action of RNA-dependent RNA polymerases (RDRs), which use single stranded RNA to generate dsRNA that in turn is targeted by DCL proteins. As a counter-defense, plant viruses encode viral suppressors of RNA silencing (VSRs) that target different components in the RNA silencing pathway. The tomato Ty-1 gene confers resistance to the DNA virus tomato yellow leaf curl virus (TYLCV) and has been reported to encode an RDRγ protein. However, the molecular mechanisms by which Ty-1 controls TYLCV infection, including whether Ty-1 is involved in RNA silencing, are unknown. Here, by using a transient expression assay, we have confirmed that Ty-1 shows antiviral activity against TYLCV in Nicotiana benthamiana. Also, in transient expression-based silencing assays, Ty-1 augmented systemic transgene silencing in GFP transgenic N. benthamiana plants. Furthermore, co-expression of Ty-1 or other RDRγ proteins from N. benthamiana or Arabidopsis with various proteins resulted in lower protein expression. These results are consistent with a model wherein Ty-1-mediated resistance to TYLCV is due, at least in part, to an increase in RNA silencing activity.
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Affiliation(s)
- Xiaofang Ma
- Hubei Key Laboratory of Germplasm Innovation and Utilization of Fruit Trees, Research Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan, 430064, Hubei, People's Republic of China.
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China.
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Blvd.de l'Université, Sherbrooke, QC, J1K 2R1, Canada.
| | - Yijun Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, Jiangsu, People's Republic of China
| | - Liming Wu
- Hubei Key Laboratory of Germplasm Innovation and Utilization of Fruit Trees, Research Institute of Fruit and Tea, Hubei Academy of Agricultural Sciences, Wuhan, 430064, Hubei, People's Republic of China
| | - Peter Moffett
- Centre SÈVE, Département de Biologie, Université de Sherbrooke, 2500 Blvd.de l'Université, Sherbrooke, QC, J1K 2R1, Canada.
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2
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Jammes M, Golyaev V, Fuentes A, Laboureau N, Urbino C, Plissonneau C, Peterschmitt M, Pooggin MM. Transcriptome and small RNAome profiling uncovers how a recombinant begomovirus evades RDRγ-mediated silencing of viral genes and outcompetes its parental virus in mixed infection. PLoS Pathog 2024; 20:e1011941. [PMID: 38215155 PMCID: PMC10810479 DOI: 10.1371/journal.ppat.1011941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 01/25/2024] [Accepted: 01/03/2024] [Indexed: 01/14/2024] Open
Abstract
Tomato yellow leaf curl virus (TYLCV, genus Begomovirus, family Geminiviridae) causes severe disease of cultivated tomatoes. Geminiviruses replicate circular single-stranded genomic DNA via rolling-circle and recombination-dependent mechanisms, frequently generating recombinants in mixed infections. Circular double-stranded intermediates of replication also serve as templates for Pol II bidirectional transcription. IS76, a recombinant derivative of TYLCV with a short sequence in the bidirectional promoter/origin-of-replication region acquired from a related begomovirus, outcompetes TYLCV in mixed infection and breaks disease resistance in tomato Ty-1 cultivars. Ty-1 encodes a γ-clade RNA-dependent RNA polymerase (RDRγ) implicated in Dicer-like (DCL)-mediated biogenesis of small interfering (si)RNAs directing gene silencing. Here, we profiled transcriptome and small RNAome of Ty-1 resistant and control susceptible plants infected with TYLCV, IS76 or their combination at early and late infection stages. We found that RDRγ boosts production rates of 21, 22 and 24 nt siRNAs from entire genomes of both viruses and modulates DCL activities in favour of 22 and 24 nt siRNAs. Compared to parental TYLCV, IS76 undergoes faster transition to the infection stage favouring rightward transcription of silencing suppressor and coat protein genes, thereby evading RDRγ activity and facilitating its DNA accumulation in both single and mixed infections. In coinfected Ty-1 plants, IS76 efficiently competes for host replication and transcription machineries, thereby impairing TYLCV replication and transcription and forcing its elimination associated with further increased siRNA production. RDRγ is constitutively overexpressed in Ty-1 plants, which correlates with begomovirus resistance, while siRNA-generating DCLs (DCL2b/d, DCL3, DCL4) and genes implicated in siRNA amplification (α-clade RDR1) and function (Argonaute2) are upregulated to similar levels in TYLCV- and IS76-infected susceptible plants. Collectively, IS76 recombination facilitates replication and promotes expression of silencing suppressor and coat proteins, which allows the recombinant virus to evade the negative impact of RDRγ-boosted production of viral siRNAs directing transcriptional and posttranscriptional silencing.
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Affiliation(s)
- Margaux Jammes
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
| | - Victor Golyaev
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
| | | | - Nathalie Laboureau
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
| | - Cica Urbino
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
| | | | - Michel Peterschmitt
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
| | - Mikhail M. Pooggin
- PHIM Plant Health Institute, University Montpellier, CIRAD, INRAE, IRD, Institute Agro, Montpellier, France
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3
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Lettin L, Erbay B, Blair GE. Viruses and Cajal Bodies: A Critical Cellular Target in Virus Infection? Viruses 2023; 15:2311. [PMID: 38140552 PMCID: PMC10747631 DOI: 10.3390/v15122311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Nuclear bodies (NBs) are dynamic structures present in eukaryotic cell nuclei. They are not bounded by membranes and are often considered biomolecular condensates, defined structurally and functionally by the localisation of core components. Nuclear architecture can be reorganised during normal cellular processes such as the cell cycle as well as in response to cellular stress. Many plant and animal viruses target their proteins to NBs, in some cases triggering their structural disruption and redistribution. Although not all such interactions have been well characterised, subversion of NBs and their functions may form a key part of the life cycle of eukaryotic viruses that require the nucleus for their replication. This review will focus on Cajal bodies (CBs) and the viruses that target them. Since CBs are dynamic structures, other NBs (principally nucleoli and promyelocytic leukaemia, PML and bodies), whose components interact with CBs, will also be considered. As well as providing important insights into key virus-host cell interactions, studies on Cajal and associated NBs may identify novel cellular targets for development of antiviral compounds.
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Affiliation(s)
- Lucy Lettin
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
| | - Bilgi Erbay
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
- Moleküler Biyoloji ve Genetik Bölümü, Fen Fakültesi, Van Yuzuncu Yil University, Van 65140, Türkiye
| | - G. Eric Blair
- School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK (B.E.)
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4
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Fortes IM, Fernández-Muñoz R, Moriones E. Crinivirus Tomato Chlorosis Virus Compromises the Control of Tomato Yellow Leaf Curl Virus in Tomato Plants by the Ty-1 Gene. PHYTOPATHOLOGY 2023; 113:1347-1359. [PMID: 36690608 DOI: 10.1094/phyto-09-22-0334-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato crops in warm regions of the world, and is associated with infections of several whitefly (Bemisia tabaci)-transmitted single-stranded (ss)DNA begomoviruses (genus Begomovirus, family Geminiviridae). The most widespread begomovirus isolates associated with TYLCD are those of the type strain of the Tomato yellow leaf curl virus species, known as Israel (TYLCV-IL). The Ty-1 gene is widely used in commercial tomato cultivars to control TYLCV-IL damage, providing resistance to the virus by restricting viral accumulation and tolerance to TYLCD by inhibiting disease symptoms. However, several reports suggest that TYLCV-IL-like isolates are adapting to the Ty-1 gene and are causes of concern for possibly overcoming the provided control. This is the case with TYLCV-IL IS76-like recombinants that have a small genome fragment acquired by genetic exchange from an isolate of Tomato yellow leaf curl Sardinia virus, another begomovirus species associated with TYLCD. Here we show that TYLCV-IL IS76-like isolates partially break down the TYLCD-tolerance provided by the Ty-1 gene and that virulence differences might exist between isolates. Interestingly, we demonstrate that mixed infections with an isolate of the crinivirus (genus Crinivirus, family Closteroviridae) species Tomato chlorosis virus (ToCV), an ssRNA virus also transmitted by B. tabaci and emerging worldwide in tomato crops, boosts the breakdown of the TYLCD-tolerance provided by the Ty-1 gene either with TYLCV-IL IS76-like or canonical TYLCV-IL isolates. Moreover, we demonstrate the incorporation of the Ty-2 gene in Ty-1-commercial tomatoes to restrict (no virus or virus traces, no symptoms) systemic infections of recombinant TYLCV-IL IS76-like and canonical TYLCV-IL isolates, even in the presence of ToCV infections, which provides more robust and durable control of TYLCD.
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Affiliation(s)
- Isabel M Fortes
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM), Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Estación Experimental "La Mayora", E-29750 Algarrobo-Costa, Málaga, Spain
| | - Rafael Fernández-Muñoz
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM), Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Estación Experimental "La Mayora", E-29750 Algarrobo-Costa, Málaga, Spain
| | - Enrique Moriones
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM), Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Estación Experimental "La Mayora", E-29750 Algarrobo-Costa, Málaga, Spain
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5
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Liu H, Chang Z, Zhao S, Gong P, Zhang M, Lozano-Durán R, Yan H, Zhou X, Li F. Functional identification of a novel C7 protein of tomato yellow leaf curl virus. Virology 2023; 585:117-126. [PMID: 37331112 DOI: 10.1016/j.virol.2023.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/23/2023] [Accepted: 05/25/2023] [Indexed: 06/20/2023]
Abstract
Tomato yellow leaf curl virus (TYLCV) is a monopartite geminivirus, and one of the most devastating plant viruses in the world. TYLCV is traditionally known to encode six viral proteins in bidirectional and partially overlapping open reading frames (ORFs). However, recent studies have shown that TYLCV encodes additional small proteins with specific subcellular localizations and potential virulence functions. Here, a novel protein named C7, encoded by a newly-described ORF in the complementary strand, was identified as part of the TYLCV proteome using mass spectrometry. The C7 protein localized to the nucleus and cytoplasm, both in the absence and presence of the virus. C7 was found to interact with two other TYLCV-encoded proteins: with C2 in the nucleus, and with V2 in the cytoplasm, forming conspicuous granules. Mutation of C7 start codon ATG to ACG to block the translation of C7 delayed the onset of viral infection, and the mutant virus caused milder virus symptoms and less accumulations of viral DNAs and proteins. Using the potato virus X (PVX)-based recombinant vector, we found that ectopic overexpression of C7 resulted in more severe mosaic symptoms and promoted a higher accumulation of PVX-encoded coat protein in the late virus infection stage. In addition, C7 was also found to inhibit GFP-induced RNA silencing moderately. This study demonstrates that the novel C7 protein encoded by TYLCV is a pathogenicity factor and a weak RNA silencing suppressor, and that it plays a critical role during TYLCV infection.
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Affiliation(s)
- He Liu
- College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, 071000, China; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Zhaoyang Chang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Siwen Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Pan Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Mingzhen Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Rosa Lozano-Durán
- Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, D-72076 Tübingen, Germany
| | - Hongfei Yan
- College of Plant Protection, Hebei Agricultural University, Baoding, Hebei, 071000, 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, Zhejiang, 310058, China.
| | - Fangfang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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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 PMCID: PMC10205009 DOI: 10.1371/journal.pone.0286149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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7
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Nigam D, Muthukrishnan E, Flores-López LF, Nigam M, Wamaitha MJ. Comparative Genome Analysis of Old World and New World TYLCV Reveals a Biasness toward Highly Variable Amino Acids in Coat Protein. PLANTS (BASEL, SWITZERLAND) 2023; 12:1995. [PMID: 37653912 PMCID: PMC10223811 DOI: 10.3390/plants12101995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 09/02/2023]
Abstract
Begomoviruses, belonging to the family Geminiviridae and the genus Begomovirus, are DNA viruses that are transmitted by whitefly Bemisia tabaci (Gennadius) in a circulative persistent manner. They can easily adapt to new hosts and environments due to their wide host range and global distribution. However, the factors responsible for their adaptability and coevolutionary forces are yet to be explored. Among BGVs, TYLCV exhibits the broadest range of hosts. In this study, we have identified variable and coevolving amino acid sites in the proteins of Tomato yellow leaf curl virus (TYLCV) isolates from Old World (African, Indian, Japanese, and Oceania) and New World (Central and Southern America). We focused on mutations in the coat protein (CP), as it is highly variable and interacts with both vectors and host plants. Our observations indicate that some mutations were accumulating in Old World TYLCV isolates due to positive selection, with the S149N mutation being of particular interest. This mutation is associated with TYLCV isolates that have spread in Europe and Asia and is dominant in 78% of TYLCV isolates. On the other hand, the S149T mutation is restricted to isolates from Saudi Arabia. We further explored the implications of these amino acid changes through structural modeling. The results presented in this study suggest that certain hypervariable regions in the genome of TYLCV are conserved and may be important for adapting to different host environments. These regions could contribute to the mutational robustness of the virus, allowing it to persist in different host populations.
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Affiliation(s)
- Deepti Nigam
- Institute for Genomics of Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University (TTU), Lubbock, TX 79409, USA
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY 14850, USA
| | | | - Luis Fernando Flores-López
- Departamento de Biotecnología y Bioquímica, Centro de Investigacióny de Estudios Avanzados de IPN (CINVESTAV) Unidad Irapuato, Irapuato 368224, Mexico
| | - Manisha Nigam
- Department of Biochemistry, Hemvati Nandan Bahuguna Garhwal University, Srinagar 246174, Uttarakhand, India
| | - Mwathi Jane Wamaitha
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi P.O. Box 14733-00800, Kenya
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8
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Malavika M, Prakash V, Chakraborty S. Recovery from virus infection: plant's armory in action. PLANTA 2023; 257:103. [PMID: 37115475 DOI: 10.1007/s00425-023-04137-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/14/2023] [Indexed: 05/26/2023]
Abstract
MAIN CONCLUSION This review focuses on different factors involved in promoting symptom recovery in plants post-virus infection such as epigenetics, transcriptional reprogramming, phytohormones with an emphasis on RNA silencing as well as role of abiotic factors such as temperature on symptom recovery. Plants utilize several different strategies to defend themselves in the battle against invading viruses. Most of the viral proteins interact with plant proteins and interfere with molecular dynamics in a cell which eventually results in symptom development. This initial symptom development is countered by the plant utilizing various factors including the plant's adaptive immunity to develop a virus tolerant state. Infected plants can specifically target and impede the transcription of viral genes as well as degrade the viral transcripts to restrict their proliferation by the production of small-interfering RNA (siRNA) generated from the viral nucleic acid, known as virus-derived siRNA (vsiRNA). To further escalate the degradation of viral nucleic acid, secondary siRNAs are generated. The production of virus-activated siRNA (vasiRNA) from the host genome causes differential regulation of the host transcriptome which plays a major role in establishing a virus tolerant state within the infected plant. The systemic action of vsiRNAs, vasiRNA, and secondary siRNAs with the help of defense hormones like salicylic acid can curb viral proliferation, and thus the newly emerged leaves develop fewer symptoms, maintaining a state of tolerance.
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Affiliation(s)
- M Malavika
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ved Prakash
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- Department of Plant Pathology, Kansas State University, Manhattan, KS, 66506, USA
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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9
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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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10
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Arora H, Singh RK, Sharma S, Sharma N, Panchal A, Das T, Prasad A, Prasad M. DNA methylation dynamics in response to abiotic and pathogen stress in plants. PLANT CELL REPORTS 2022; 41:1931-1944. [PMID: 35833989 DOI: 10.1007/s00299-022-02901-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
DNA methylation is a dynamic epigenetic mechanism that plays a significant role in gene expression and also maintains chromatin stability. The process is conserved in both plants and animals, and crucial for development and stress responses. Differential DNA methylation during adverse environmental conditions or pathogen attack facilitates the selective expression of defense-related genes. Both stress-induced DNA hypomethylation and hypermethylation play beneficial roles in activating the defense response. These DNA marks may be carried to the next generation making the progenies 'primed' for abiotic and biotic stress responses. Over the recent years, rapid advancements in the area of high throughput sequencing have enabled the detection of methylation status at genome levels in several plant species. Epigenotyping offers an alternative tool to plant breeders in addition to conventional markers for the selection of the desired offspring. In this review, we briefly discuss the mechanism of DNA methylation, recent understanding of DNA methylation-mediated gene regulation during abiotic and biotic stress responses, and stress memory in plants.
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Affiliation(s)
- Heena Arora
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Roshan Kumar Singh
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Shambhavi Sharma
- 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
- Institute of Life Sciences, NALCO Nagar, Bhubaneswar, 751023, India
| | - Anurag Panchal
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Tuhin Das
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ashish Prasad
- 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.
- Department of Plant Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India.
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11
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Wu X, Chai M, Liu J, Jiang X, Yang Y, Guo Y, Li Y, Cheng X. Turnip mosaic virus manipulates DRM2 expression to regulate host CHH and CHG methylation for robust infection. STRESS BIOLOGY 2022; 2:29. [PMID: 37676449 PMCID: PMC10441925 DOI: 10.1007/s44154-022-00052-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/12/2022] [Indexed: 09/08/2023]
Abstract
DNA methylation is an important epigenetic marker for the suppression of transposable elements (TEs) and the regulation of plant immunity. However, little is known how RNA viruses counter defense such antiviral machinery. In this study, the change of DNA methylation in turnip mosaic virus (TuMV)-infected cells was analyzed by whole genome bisulfite sequencing. Results showed that the total number of methylated sites of CHH and CHG increased in TuMV-infected cells, the majority of differentially methylated regions (DMRs) in the CHH and CHG contexts were associated with hypermethylation. Gene expression analysis showed that the expression of two methylases (DRM2 and CMT3) and three demethylases (ROS3, DML2, DML3) was significantly increased and decreased in TuMV-infected cells, respectively. Pathogenicity tests showed that the enhanced resistance to TuMV of the loss-of-function mutant of DRM2 is associated with unregulated expression of several defense-related genes. Finally, we found TuMV-encoded NIb, the viral RNA-dependent RNA polymerase, was able to induce the expression of DRM2. In conclusion, this study discovered that TuMV can modulate host DNA methylation by regulating the expression of DRM2 to promote virus infection.
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Affiliation(s)
- Xiaoyun Wu
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Mengzhu Chai
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Jiahui Liu
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Xue Jiang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Yingshuai Yang
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Yushuang Guo
- Key Laboratory of Molecular Genetics, Guizhou Academy of Tobacco Science, Guiyang, 550081 China
| | - Yong Li
- College of Life Science, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
| | - Xiaofei Cheng
- Key Laboratory of Germplasm Enhancement, Physiology and Ecology of Food Crops in Cold Region of Chinese Education Ministry, College of Agriculture, Northeast Agricultural University, Harbin, 150030 Heilongjiang China
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12
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Zhao L, Che X, Wang Z, Zhou X, Xie Y. Functional Characterization of Replication-Associated Proteins Encoded by Alphasatellites Identified in Yunnan Province, China. Viruses 2022; 14:222. [PMID: 35215816 PMCID: PMC8875141 DOI: 10.3390/v14020222] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 12/20/2022] Open
Abstract
Alphasatellites, which encode only a replication-associated protein (alpha-Rep), are frequently found to be non-essential satellite components associated with begomovirus/betasatellite complexes, and their presence can modulate disease symptoms and/or viral DNA accumulation during infection. Our previous study has shown that there are three types of alphasatellites associated with begomovirus/betasatellite complexes in Yunnan province in China and they encode three corresponding types of alpha-Rep proteins. However, the biological functions of alpha-Reps remain poorly understood. In this study, we investigated the biological functions of alpha-Reps in post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) using 16c and 16-TGS transgenic Nicotiana benthamiana plants. Results showed that all the three types of alpha-Rep proteins were capable of suppressing the PTGS and reversing the TGS. Among them, the alpha-Rep of Y10DNA1 has the strongest PTGS and TGS suppressor activities. We also found that the alpha-Rep proteins were able to increase the accumulation of their helper virus during coinfection. These results suggest that the alpha-Reps may have a role in overcoming host defense, which provides a possible explanation for the selective advantage provided by the association of alphasatellites with begomovirus/betasatellite complexes.
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Affiliation(s)
- Liling Zhao
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
- Biotechnology and Germplasm Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650223, China
| | - Xuan Che
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
| | - Zhanqi Wang
- Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China;
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
- Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; (L.Z.); (X.C.); (X.Z.)
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13
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Pantaleo V, Masuta C. Diversity of viral RNA silencing suppressors and their involvement in virus-specific symptoms. Adv Virus Res 2022; 113:1-23. [DOI: 10.1016/bs.aivir.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Mastrevirus Rep and RepA Proteins Suppress de novo Transcriptional Gene Silencing. Int J Mol Sci 2021; 22:ijms222111462. [PMID: 34768892 PMCID: PMC8584122 DOI: 10.3390/ijms222111462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/13/2021] [Accepted: 10/19/2021] [Indexed: 01/13/2023] Open
Abstract
Transcriptional gene silencing (TGS) in plants is a defense mechanism against DNA virus infection. The genomes of viruses in the Geminiviridae family encode several TGS suppressors. In this study, we induced de novo TGS against the transgenic GFP gene encoding green fluorescent protein by expressing a hairpin-shaped self-complementary RNA corresponding to the enhancer region of the 35S promoter (hpE35S). In addition, we examined the TGS suppression activity of proteins encoded in the genome of Tobacco yellow dwarf virus (TYDV, genus Mastrevirus). The results show that the replication-associated protein (Rep) and RepA encoded by TYDV have TGS suppressor activity and lead to decreased accumulation of 24-nt siRNAs. These results suggest that Rep and RepA can block the steps before the loading of siRNAs into Argonaute (AGO) proteins. This is the first report of TGS suppressors in the genus Mastrevirus.
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15
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Zhao W, Zhou Y, Zhou X, Wang X, Ji Y. Host GRXC6 restricts Tomato yellow leaf curl virus infection by inhibiting the nuclear export of the V2 protein. PLoS Pathog 2021; 17:e1009844. [PMID: 34398921 PMCID: PMC8389846 DOI: 10.1371/journal.ppat.1009844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 08/26/2021] [Accepted: 07/27/2021] [Indexed: 11/27/2022] Open
Abstract
Geminiviruses cause serious symptoms and devastating losses in crop plants. With a circular, single-stranded DNA genome, geminiviruses multiply their genomic DNA in the nucleus, requiring the nuclear shuttling of viral proteins and viral genomic DNAs. Many host factors, acting as proviral or antiviral factors, play key roles in geminivirus infections. Here, we report the roles of a tomato glutaredoxin (GRX), SlGRXC6, in the infection of Tomato yellow leaf curl virus (TYLCV), a single-component geminivirus. The V2 protein of TYLCV specifically and preferentially interacts with SlGRXC6 among the 55-member tomato GRX family that are broadly involved in oxidative stress responses, plant development, and pathogen responses. We show that overexpressed SlGRXC6 increases the nuclear accumulation of V2 by inhibiting its nuclear export and, in turn, inhibits trafficking of the V1 protein and viral genomic DNA. Conversely, the silenced expression of SlGRXC6 leads to an enhanced susceptibility to TYLCV. SlGRXC6 is also involved in symptom development as we observed a positive correlation where overexpression of SlGRXC6 promotes while knockdown of SlGRXC6 expression inhibits plant growth. We further showed that SlGRXC6 works with SlNTRC80, a tomato NADPH-dependent thioredoxin reductase, to regulate plant growth. V2 didn’t interact with SlNTRC80 but competed with SlNTR80 for binding to SlGRXC6, suggesting that the V2-disrupted SlGRXC6-SlNTRC80 interaction is partially responsible for the virus-caused symptoms. These results suggest that SlGRXC6 functions as a host restriction factor that inhibits the nuclear trafficking of viral components and point out a new way to control TYLCV infection by targeting the V2-SlGRXC6 interaction. Geminiviruses infect numerous crops, induce a wide range of symptoms, and cause tremendous crop losses annually. Tomato yellow leaf curl virus (TYLCV), a single-component geminivirus, is a causative agent leading to one of the most devastating tomato diseases in the world. As a single-stranded DNA virus, genomic replication occurs in the nucleus and therefore, the nuclear shuttling is a critical step of viral infection. The V2 protein of TYLCV is involved in symptom development and viral trafficking, among other steps, and hijacks host proteins for executing its functions. Nevertheless, host factors involved in the V2-mediated functions are not well addressed. We show that tomato GRXC6 (SlGRXC6) functions as a restriction factor of TYLCV infection by interacting with and preventing V2 from moving out of the nucleus, leading to the inhibited V2-mediated nuclear export of V1 and the V1-viral DNA complex. SlGRXC6 also contributes to symptom development via its interaction with SINTRC80. V2 sequesters SlGRXC6 from forming the SlGRXC6-SlNTRC80 complex and regulates plant growth. Our work, therefore, identified a new host partner of V2 and revealed the mechanisms whereby V2 functions as a pathogenicity determinant and can be targeted for virus control.
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Affiliation(s)
- Wenhao Zhao
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Yijun Zhou
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xueping Zhou
- State Key Laboratory for Biology of Plant Disease 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
- * E-mail: (XZ); (XW); (YJ)
| | - Xiaofeng Wang
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail: (XZ); (XW); (YJ)
| | - Yinghua Ji
- Key Lab of Food Quality and Safety of Jiangsu Province—State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- * E-mail: (XZ); (XW); (YJ)
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16
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Gong P, Tan H, Zhao S, Li H, Liu H, Ma Y, Zhang X, Rong J, Fu X, Lozano-Durán R, Li F, Zhou X. Geminiviruses encode additional small proteins with specific subcellular localizations and virulence function. Nat Commun 2021; 12:4278. [PMID: 34257307 PMCID: PMC8277811 DOI: 10.1038/s41467-021-24617-4] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 06/21/2021] [Indexed: 12/14/2022] Open
Abstract
Geminiviruses are plant viruses with limited coding capacity. Geminivirus-encoded proteins are traditionally identified by applying a 10-kDa arbitrary threshold; however, it is increasingly clear that small proteins play relevant roles in biological systems, which calls for the reconsideration of this criterion. Here, we show that geminiviral genomes contain additional ORFs. Using tomato yellow leaf curl virus, we demonstrate that some of these small ORFs are expressed during the infection, and that the encoded proteins display specific subcellular localizations. We prove that the largest of these additional ORFs, which we name V3, is required for full viral infection, and that the V3 protein localizes in the Golgi apparatus and functions as an RNA silencing suppressor. These results imply that the repertoire of geminiviral proteins can be expanded, and that getting a comprehensive overview of the molecular plant-geminivirus interactions will require the detailed study of small ORFs so far neglected.
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Affiliation(s)
- Pan Gong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huang Tan
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Siwen Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hao Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hui Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yu Ma
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Xi Zhang
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Junjie Rong
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Xing Fu
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China.
- Department of Plant Biochemistry, Center for Plant Molecular Biology (ZMBP), Eberhard Karls University, Tübingen, Germany.
| | - Fangfang Li
- 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, Zhejiang, China.
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17
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Gupta N, Reddy K, Bhattacharyya D, Chakraborty✉ S. Plant responses to geminivirus infection: guardians of the plant immunity. Virol J 2021; 18:143. [PMID: 34243802 PMCID: PMC8268416 DOI: 10.1186/s12985-021-01612-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Geminiviruses are circular, single-stranded viruses responsible for enormous crop loss worldwide. Rapid expansion of geminivirus diversity outweighs the continuous effort to control its spread. Geminiviruses channelize the host cell machinery in their favour by manipulating the gene expression, cell signalling, protein turnover, and metabolic reprogramming of plants. As a response to viral infection, plants have evolved to deploy various strategies to subvert the virus invasion and reinstate cellular homeostasis. MAIN BODY Numerous reports exploring various aspects of plant-geminivirus interaction portray the subtlety and flexibility of the host-pathogen dynamics. To leverage this pool of knowledge towards raising antiviral resistance in host plants, a comprehensive account of plant's defence response against geminiviruses is required. This review discusses the current knowledge of plant's antiviral responses exerted to geminivirus in the light of resistance mechanisms and the innate genetic factors contributing to the defence. We have revisited the defence pathways involving transcriptional and post-transcriptional gene silencing, ubiquitin-proteasomal degradation pathway, protein kinase signalling cascades, autophagy, and hypersensitive responses. In addition, geminivirus-induced phytohormonal fluctuations, the subsequent alterations in primary and secondary metabolites, and their impact on pathogenesis along with the recent advancements of CRISPR-Cas9 technique in generating the geminivirus resistance in plants have been discussed. CONCLUSIONS Considering the rapid development in the field of plant-virus interaction, this review provides a timely and comprehensive account of molecular nuances that define the course of geminivirus infection and can be exploited in generating virus-resistant plants to control global agricultural damage.
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Affiliation(s)
- Neha Gupta
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Kishorekumar Reddy
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Dhriti Bhattacharyya
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
| | - Supriya Chakraborty✉
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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18
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Positive selection and intrinsic disorder are associated with multifunctional C4(AC4) proteins and geminivirus diversification. Sci Rep 2021; 11:11150. [PMID: 34045539 PMCID: PMC8160170 DOI: 10.1038/s41598-021-90557-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/13/2021] [Indexed: 02/06/2023] Open
Abstract
Viruses within the Geminiviridae family cause extensive agricultural losses. Members of four genera of geminiviruses contain a C4 gene (AC4 in geminiviruses with bipartite genomes). C4(AC4) genes are entirely overprinted on the C1(AC1) genes, which encode the replication-associated proteins. The C4(AC4) proteins exhibit diverse functions that may be important for geminivirus diversification. In this study, the influence of natural selection on the evolutionary diversity of 211 C4(AC4) genes relative to the C1(AC1) sequences they overlap was determined from isolates of the Begomovirus and Curtovirus genera. The ratio of nonsynonymous (dN) to synonymous (dS) nucleotide substitutions indicated that C4(AC4) genes are under positive selection, while the overlapped C1(AC1) sequences are under purifying selection. Ninety-one of 200 Begomovirus C4(AC4) genes encode elongated proteins with the extended regions being under neutral selection. C4(AC4) genes from begomoviruses isolated from tomato from native versus exotic regions were under similar levels of positive selection. Analysis of protein structure suggests that C4(AC4) proteins are entirely intrinsically disordered. Our data suggest that non-synonymous mutations and mutations that increase the length of C4(AC4) drive protein diversity that is intrinsically disordered, which could explain C4/AC4 functional variation and contribute to both geminivirus diversification and host jumping.
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19
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Basu S, Singh AK, Singh D, Sahu SK, Chakraborty S. Role of viral suppressors governing asymmetric synergism between tomato-infecting begomoviruses. Appl Microbiol Biotechnol 2021; 105:1107-1121. [PMID: 33417040 DOI: 10.1007/s00253-020-11070-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 12/01/2020] [Accepted: 12/17/2020] [Indexed: 11/29/2022]
Abstract
Mixed viral infections are common in fields and frequently exacerbate disease severity via synergistic interactions among individual viral genomic components leading to major crop loss. Two predominant species of tomato-infecting begomoviruses, Tomato leaf curl New Delhi virus (ToLCNDV) and Tomato leaf curl Gujarat virus (ToLCGuV), are known to cause severe leaf curl disease of tomato in India. Previously, we have demonstrated asymmetric synergism between these two distinct begomovirus species during mixed infection in solanaceous hosts. In the present study, we have identified the underlying proteins that positively regulate asymmetric synergism and their effect on plant defense machinery. During co-infection, the AC2 and AV2 of ToLCGuV enhanced ToLCNDV DNA accumulation in Nicotiana benthamiana as well as in their natural host, tomato. Furthermore, we found that AC2 and AV2 of ToLCNDV and AV2 of ToLCGuV play a critical role in suppression of post transcriptional gene silencing (PTGS) machinery. Taken together, AC2 and AV2 encoded proteins of ToLCGuV are the crucial viral factors promoting asymmetric synergism with ToLCNDV. KEY POINTS: • Begomoviral suppressors play vital roles in viral synergism. • AC2 and AV2 of ToLCGuV asymmetrically enhance ToLCNDV accumulation. • AC2 and AV2 of ToLCNDV and ToLCGuV AV2 are major PTGS suppressors.
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Affiliation(s)
- Saumik Basu
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India
- Department of Entomology, Washington State University, Pullman, WA, USA
| | - Ashish Kumar Singh
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India
| | - Divya Singh
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India
| | - Sanjeeb Kumar Sahu
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India
- Salk Institute for Biological Studies, 10010 N. Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Supriya Chakraborty
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110 067, India.
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20
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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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21
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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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22
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Wang L, Ding Y, He L, Zhang G, Zhu JK, Lozano-Duran R. A virus-encoded protein suppresses methylation of the viral genome through its interaction with AGO4 in the Cajal body. eLife 2020; 9:e55542. [PMID: 33064077 PMCID: PMC7567605 DOI: 10.7554/elife.55542] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 09/23/2020] [Indexed: 12/11/2022] Open
Abstract
In plants, establishment of de novo DNA methylation is regulated by the RNA-directed DNA methylation (RdDM) pathway. RdDM machinery is known to concentrate in the Cajal body, but the biological significance of this localization has remained elusive. Here, we show that the antiviral methylation of the Tomato yellow leaf curl virus (TYLCV) genome requires the Cajal body in Nicotiana benthamiana cells. Methylation of the viral genome is countered by a virus-encoded protein, V2, which interacts with the central RdDM component AGO4, interfering with its binding to the viral DNA; Cajal body localization of the V2-AGO4 interaction is necessary for the viral protein to exert this function. Taken together, our results draw a long sought-after functional connection between RdDM, the Cajal body, and antiviral DNA methylation, paving the way for a deeper understanding of DNA methylation and antiviral defences in plants.
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Affiliation(s)
- Liping Wang
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
| | - Yi Ding
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
- University of the Chinese Academy of SciencesBeijingChina
| | - Li He
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
| | - Guiping Zhang
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
| | - Jian-Kang Zhu
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
| | - Rosa Lozano-Duran
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of SciencesBeijingChina
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23
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Wang D, Sun S, Ren Y, Li S, Yang X, Zhou X. RepA Promotes the Nucleolar Exclusion of the V2 Protein of Mulberry Mosaic Dwarf-Associated Virus. Front Microbiol 2020; 11:1828. [PMID: 32903838 PMCID: PMC7438950 DOI: 10.3389/fmicb.2020.01828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/13/2020] [Indexed: 01/23/2023] Open
Abstract
Plant viruses have limited coding capacities so that they rely heavily on the expression of multifunctional viral proteins to achieve a successful infection. The functional specification of viral proteins is often related to their differential interaction with plant and viral components and somewhat depends on their localization to various subcellular compartments. In this study, we analyzed the intracellular localization of the V2 protein of Mulberry mosaic dwarf-associated virus (MMDaV), an unsigned species of the family Geminiviridae. We show that the V2 protein colocalizes with the nucleolar protein fibrillarin (NbFib2) in the nucleolus upon transient expression in the epidermal cells of Nicotiana benthamiana. A yeast-two hybrid assay, followed by bimolecular fluorescence complementation assays, demonstrated the specific interaction between V2 and NbFib2. Intriguingly, we find that the presence of MMDaV excludes the V2 protein from the nucleolus to nucleoplasm. We present evidence that the replication-associated protein A (RepA) protein of MMDaV interacts with V2 and enables the nucleolar exclusion of V2. We also show that, while V2 interacts with itself primarily in the nucleolus, the presence of RepA redirects the site of V2-V2 interaction from the nucleolus to the nucleoplasm. We further reveal that RepA promotes V2 out of the nucleolus presumably by directing the NbFib2-V2 complex from the nucleolus to the nucleoplasm. Considering the critical role of the nucleolus in plant virus infection, this RepA-dependent modulation of V2 nucleolar localization would be crucial for understanding the involvement of this subcellular compartment in plant-virus interactions.
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Affiliation(s)
- Dongxue Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Shaoshuang Sun
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yanxiang Ren
- 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 Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Shifang Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiuling Yang
- 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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24
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Aguilar E, Garnelo Gomez B, Lozano-Duran R. Recent advances on the plant manipulation by geminiviruses. CURRENT OPINION IN PLANT BIOLOGY 2020; 56:56-64. [PMID: 32464465 DOI: 10.1016/j.pbi.2020.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/06/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
As intracellular parasites, viruses co-opt the molecular machinery of the cells they infect in order to multiply and spread, and the extensiveness and effectiveness of this manipulation ultimately determine the outcome of the interaction between virus and host. Members of the Geminiviridae family, causal agents of devastating diseases in crops, encode only a handful of multifunctional, fast-evolving proteins, which efficiently target host proteins to re-wire plant development and physiology and enable replication and spread of the viral genome. In this review, we offer an overview of the different steps in the geminiviral invasion of the host plant, and explore the knowns and unknowns in geminivirus biology.
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Affiliation(s)
- Emmanuel Aguilar
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Borja Garnelo Gomez
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China
| | - Rosa Lozano-Duran
- Shanghai Center for Plant Stress Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 201602, China.
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25
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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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26
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Zhao W, Wu S, Barton E, Fan Y, Ji Y, Wang X, Zhou Y. Tomato Yellow Leaf Curl Virus V2 Protein Plays a Critical Role in the Nuclear Export of V1 Protein and Viral Systemic Infection. Front Microbiol 2020; 11:1243. [PMID: 32587585 PMCID: PMC7297916 DOI: 10.3389/fmicb.2020.01243] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/14/2020] [Indexed: 11/13/2022] Open
Abstract
Geminiviruses are an important group of circular, single-stranded DNA viruses that cause devastating diseases in crops. Geminiviruses replicate their genomic DNA in the nucleus and the newly synthesized viral DNA is subsequently transported to the cytoplasm for further cell-to-cell and long-distance movement to establish systemic infection. Thus, nucleocytoplasmic transportation is crucial for successful infection by geminiviruses. For Tomato yellow leaf curl virus (TYLCV), the V1 protein is known to bind and shuttle viral genomic DNA, however, the role of the V2 protein in this process is still unclear. Here, we report that the V1 protein is primarily localized in the nucleus when expressed but the nucleus-localized V1 protein dramatically decreases when co-expressed with V2 protein. Moreover, the V2-facilitated nuclear export of V1 protein depends on host exportin-α and a specific V1-V2 interaction. Chemical inhibition of exportin-α or a substitution at cysteine 85 of the V2 protein, which abolishes the V1-V2 interaction, blocks redistribution of the V1 protein to the perinuclear region and the cytoplasm. When the V2C85S mutation is incorporated into a TYLCV infectious clone, the TYLCV-C85S causes delayed onset of very mild symptoms compared to wild-type TYLCV, suggesting that the V1-V2 interaction and, thus, the V2-mediated nuclear export of the V1 protein is crucial for viral spread and systemic infection. Our data point to a critical role of the V2 protein in promoting the nuclear export of the V1 protein and viral systemic infection, likely by promoting V1 protein-mediated nucleocytoplasmic transportation of TYLCV genomic DNA.
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Affiliation(s)
- Wenhao Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China.,School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Shuhua Wu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Elizabeth Barton
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Yongjian Fan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Yinghua Ji
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
| | - Xiaofeng Wang
- School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Yijun Zhou
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Nanjing, China
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27
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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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28
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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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29
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Ding Y, Lozano-Durán R. The Cajal Body in Plant-Virus Interactions. Viruses 2020; 12:E250. [PMID: 32102236 PMCID: PMC7077289 DOI: 10.3390/v12020250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 01/23/2023] Open
Abstract
Cajal bodies (CBs) are nuclear membraneless bodies composed of proteins and RNA. Although it is known that CBs play a role in RNA metabolism and the formation of functional ribonucleoprotein (RNP) particles, the whole breadth of CB functions is far from being fully elucidated. In this short review, we will summarize and discuss the growing body of evidence pointing to an involvement of this subnuclear compartment in plant-virus interactions.
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Affiliation(s)
- Yi Ding
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 201602, China;
- Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology, Chinese Academy of Sciences, Shanghai 201602, China;
- Center for Excellence in Molecular Plant Science, Chinese Academy of Sciences, Shanghai 201602, China
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30
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Gong YN, Tang RQ, Zhang Y, Peng J, Xian O, Zhang ZH, Zhang SB, Zhang DY, Liu H, Luo XW, Liu Y. The NIa-Protease Protein Encoded by the Pepper Mottle Virus Is a Pathogenicity Determinant and Releases DNA Methylation of Nicotiana benthamiana. Front Microbiol 2020; 11:102. [PMID: 32153517 PMCID: PMC7047827 DOI: 10.3389/fmicb.2020.00102] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/17/2020] [Indexed: 12/12/2022] Open
Abstract
It is well documented that the canonical function of NIa-protease (NIa-Pro) of the potyviruses is responsible for cleaving the viral polyprotein into functional proteins. Although NIa-Pro is vital for the infection cycle of potyviruses, the function of NIa-Pro in the interaction of the potyvirus host is not clear. In this study, NIa-Pro is ectopically expressed from a potato virus X (PVX) vector and infiltrates Nicotiana benthamiana wild type and 16-TGS. The pathogenicity and inhibition of host transcriptional gene silencing (TGS) are characterized. Ectopic expression of NIa-Pro from a PVX vector resulted in severe mosaic symptoms followed by a hypersensitive-like response in N. benthamiana. Furthermore, PepMoV NIa-Pro was able to reverse established TGS of a green fluorescent protein transgene by reducing methylation of promoter sequences in N. benthamiana and possessed the capacity to interfere with the global methylation of N. benthamiana. Taken together, the results of this study likely suggest that PepMoV NIa-Pro is a pathogenicity determinant and a potent suppressor of host TGS and suggest that NIa-Pro may employ novel mechanisms to suppress host antiviral defenses. To the best of our knowledge, this is the first report of a plant RNA virus modulating host TGS in a novel manner by interfering with the establishment of the methylation step of the plant DNA methylation pathway.
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Affiliation(s)
- Yi-Nuo Gong
- Longping Branch, Graduate School of Hunan University, Changsha, China
| | - Ru-Qing Tang
- Hunan Academy of Agricultural Sciences, Changsha, China
| | - Yu Zhang
- Longping Branch, Graduate School of Hunan University, Changsha, China
| | - Jing Peng
- Hunan Academy of Agricultural Sciences, Changsha, China
| | - OuYang Xian
- Hunan Academy of Agricultural Sciences, Changsha, China
| | | | - Song-Bai Zhang
- Longping Branch, Graduate School of Hunan University, Changsha, China.,Hunan Academy of Agricultural Sciences, Changsha, China
| | - De-Yong Zhang
- Longping Branch, Graduate School of Hunan University, Changsha, China.,Hunan Academy of Agricultural Sciences, Changsha, China
| | - Hui Liu
- National Agro-Tech Extension and Service Center, Beijing, China
| | - Xiang-Wen Luo
- Hunan Academy of Agricultural Sciences, Changsha, China
| | - Yong Liu
- Longping Branch, Graduate School of Hunan University, Changsha, China.,Hunan Academy of Agricultural Sciences, Changsha, China
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31
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Pérez-Padilla V, Fortes IM, Romero-Rodríguez B, Arroyo-Mateos M, Castillo AG, Moyano C, De León L, Moriones E. Revisiting Seed Transmission of the Type Strain of Tomato yellow leaf curl virus in Tomato Plants. PHYTOPATHOLOGY 2020; 110:121-129. [PMID: 31584339 DOI: 10.1094/phyto-07-19-0232-fi] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Isolates of the Tomato yellow leaf curl virus (TYLCV) species (genus Begomovirus, family Geminiviridae) infect tomato crops worldwide, causing severe economic damage. Members of the whitefly Bemisia tabaci sibling species group are the vector of begomoviruses, including TYLCV. However, transmission of isolates of the type strain (Israel [IL]) of TYLCV (TYLCV-IL) by tomato seed has recently been reported based on infections occurring in Korea. Because of the consequences of this finding on the epidemiology and control of the disease caused by TYLCV and on the seed market, it was considered essential to revisit and expand those results to other tomato-growing areas. TYLCV DNA content was detected in tomato and Nicotiana benthamiana seed collected from plants naturally or experimentally infected with TYLCV-IL, supporting its seedborne nature. The TYLCV-IL replication detected in tomato and N. benthamiana flower reproductive organs demonstrated close association of this virus with the seed during maturation. However, the significant reduction of TYLCV DNA load after surface disinfections of tomato seed suggests that most of the virus is located externally, as contaminant of the seed coat. Transmission assays, carried out with seven tomato genotypes and more than 3,000 tomato plants, revealed no evidence of seed transmission from "surface-disinfected" or untreated seed for two Mediterranean isolates of TYLCV-IL. Similar results were also obtained for seed collected from TYLCV-IL-infected N. benthamiana plants. The results support the conclusion that TYLCV-IL is seedborne but is not seed transmitted in tomato or N. benthamiana, suggesting that transmission through seed is not a general property of TYLCV.
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Affiliation(s)
- Verónica Pérez-Padilla
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Ctra. de La Coruña, km 7.5, E-28040 Madrid, Spain
| | - Isabel M Fortes
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora", E-29750 Algarrobo-Costa, Málaga, Spain
| | - Beatriz Romero-Rodríguez
- IHSM-UMA-CSIC, Área de Genética, Facultad de Ciencias, Universidad de Málaga, E-29071, Málaga, Spain
| | - Manuel Arroyo-Mateos
- IHSM-UMA-CSIC, Área de Genética, Facultad de Ciencias, Universidad de Málaga, E-29071, Málaga, Spain
| | - Araceli G Castillo
- IHSM-UMA-CSIC, Área de Genética, Facultad de Ciencias, Universidad de Málaga, E-29071, Málaga, Spain
| | - Cristina Moyano
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Ctra. de La Coruña, km 7.5, E-28040 Madrid, Spain
| | - Leandro De León
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Ctra. de La Coruña, km 7.5, E-28040 Madrid, Spain
| | - Enrique Moriones
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora", E-29750 Algarrobo-Costa, Málaga, Spain
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32
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Frequent occurrence of Mungbean yellow mosaic India virus in tomato leaf curl disease affected tomato in Oman. Sci Rep 2019; 9:16634. [PMID: 31719590 PMCID: PMC6851148 DOI: 10.1038/s41598-019-53106-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 10/23/2019] [Indexed: 11/20/2022] Open
Abstract
Next generation sequencing (NGS) of DNAs amplified by rolling circle amplification from 6 tomato (Solanum lycopersicum) plants with leaf curl symptoms identified a number of monopartite begomoviruses, including Tomato yellow leaf curl virus (TYLCV), and a betasatellite (Tomato leaf curl betasatellite [ToLCB]). Both TYLCV and ToLCB have previously been identified infecting tomato in Oman. Surprisingly the NGS results also suggested the presence of the bipartite, legume-adapted begomovirus Mungbean yellow mosaic Indian virus (MYMIV). The presence of MYMIV was confirmed by cloning and Sanger sequencing from four of the six plants. A wider analysis by PCR showed MYMIV infection of tomato in Oman to be widespread. Inoculation of plants with full-length clones showed the host range of MYMIV not to extend to Nicotiana benthamiana or tomato. Inoculation to N. benthamiana showed TYLCV to be capable of maintaining MYMIV in both the presence and absence of the betasatellite. In tomato MYMIV was only maintained by TYLCV in the presence of the betasatellite and then only at low titre and efficiency. This is the first identification of TYLCV with ToLCB and the legume adapted bipartite begomovirus MYMIV co-infecting tomato. This finding has far reaching implications. TYLCV has spread around the World from its origins in the Mediterranean/Middle East, in some instances, in live tomato planting material. The results here may suggest that begomoviruses which do not commonly infect tomato, such as MYMIV, could be spread as a passenger of TYLCV in tomato.
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33
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Zhai Z, Du J, Chen L, Hamid MR, Du X, Kong X, Cheng J, Tang W, Zhang D, Su P, Liu Y. A genetic tool for production of GFP-expressing Rhodopseudomonas palustris for visualization of bacterial colonization. AMB Express 2019; 9:141. [PMID: 31506772 PMCID: PMC6737145 DOI: 10.1186/s13568-019-0866-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/27/2019] [Indexed: 02/04/2023] Open
Abstract
Development of a genetic tool for visualization of photosynthetic bacteria (PSB) is essential for understanding microbial function during their interaction with plant and microflora. In this study, Rhodopseudomonas palustris GJ-22-gfp harboring the vector pBBR1-pckAPT-gfp was constructed using an electroporation transformation method and was used for dynamic tracing of bacteria in plants. The results showed that strain GJ-22-gfp was stable and did not affect the biocontrol function, and the Confocal Laser Scanning Microscopy (CLSM) results indicated it could successfully colonised on the surface of leaf and root of tobacco and rice. In tobacco leaves, cells formed aggregates on the mesophyll epidermal cells. While in rice, no aggregate was found. Instead, the fluorescent cells colonise the longitudinal intercellular spaces between epidermal cells. In addition, the results of strain GJ-22 on the growth promotion and disease resistance of tobacco and rice indicated that the different colonization patterns might be related to the bacteria could induce systemic resistance in tobacco.
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34
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Wang C, Wang C, Zou J, Yang Y, Li Z, Zhu S. Epigenetics in the plant-virus interaction. PLANT CELL REPORTS 2019; 38:1031-1038. [PMID: 31065780 DOI: 10.1007/s00299-019-02414-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 04/25/2019] [Indexed: 05/23/2023]
Abstract
Plants have developed diverse molecular mechanisms to resist viruses. RNA silencing plays a dominant role in antiviral defense. Recent studies have correlated plant antiviral silencing to epigenetic modification in genomic DNA and protein by remodeling the expression levels of coding genes. The plant host methylation level is reprogrammed in response to viral challenge. Genomes of some viruses have been implicated in the epigenetic modification via small RNA-mediated transcriptional gene silencing and post-transcriptional gene silencing. These mechanisms can be primed prior to a virus attack through methylation changes for antiviral defense. This review highlights the findings concerning the methylation changes in plant-virus interactions and demonstrates a possible direction to improve the understanding of plant host methylation regulation in response to viral infection.
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Affiliation(s)
- Chenguang Wang
- College of Plant Protection, China Agricultural University, Beijing, 100083, China
- Chinese Academy of Inspection and Quarantine, Beijing, 100176, China
| | - Chaonan Wang
- College of Plant Protection, China Agricultural University, Beijing, 100083, China
- Chinese Academy of Inspection and Quarantine, Beijing, 100176, China
| | - Jingze Zou
- College of Biological Sciences, China Agricultural University, Beijing, 100083, China
| | - Yunshu Yang
- Beijing Academy of Food Sciences, Beijing, 100162, China
| | - Zhihong Li
- College of Plant Protection, China Agricultural University, Beijing, 100083, China
| | - Shuifang Zhu
- College of Plant Protection, China Agricultural University, Beijing, 100083, China.
- Chinese Academy of Inspection and Quarantine, Beijing, 100176, China.
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35
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Molecular characterization and phylogenetic analysis of tomato leaf curl Palampur virus, a bipartite begomovirus, associated with Cucumis sativus L. in Pakistan. 3 Biotech 2019; 9:204. [PMID: 31139535 DOI: 10.1007/s13205-019-1727-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 04/24/2019] [Indexed: 12/28/2022] Open
Abstract
Leaf samples of Cucumis Sativus L. (C. sativus) (Family; Cucurbitaceae) showing vein thickening, mild leaf curling and leaf enations were collected from the farmer's field. Amplification of the full-length viral molecules was performed through rolling circle amplification (RCA). Cloning of the full-length viral molecules was done through standard cloning procedure followed by sequencing. Sequence similarity analysis and phylogenetic studies showed that the virus associated with leaf curling and enations in C. sativus was a bipartite begomovirus, where DNA-A and DNA-B showed highest nucleotide sequence homology of 98% and 97% to tomato leaf curl Palampur virus (ToLCPMV) from India. Attempts to isolate betasatellites and alphasatellites through PCR using RCA product as template, did not result in any amplification. A maximum likelihood phylogenetic tree grouped DNA-A and B components with other isolates from India. SDT was used to find the pairwise identity scores of different sequences of ToLCPMV present in the database. Phylogenetic analysis showed that sequences of ToLCPMV DNA-A and B components in this study share high degree of homology with existing viruses and are isolates of ToLCPMV-India. Infectious molecules of both components (Accessions, MG252783 and MG252784, respectively) were constructed for infectivity analysis to fulfill the Koch's postulate. Infectivity analysis revealed that ToLCPMV DNA-A is infectious to model host plant Nicotiana benthamiana and viral accumulation was confirmed through Southern blot analysis. Accumulation of DNA-B was confirmed through PCR. Infectivity analysis was also conducted using the original host, C. sativus, but plants were unable to survive the agroinoculation. To our knowledge this is the first report of ToLCPMV associated with C. sativus L. in Pakistan.
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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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Mubin M, Briddon RW, Mansoor S. The V2 protein encoded by a monopartite begomovirus is a suppressor of both post-transcriptional and transcriptional gene silencing activity. Gene 2019; 686:43-48. [PMID: 30399424 DOI: 10.1016/j.gene.2018.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 10/08/2018] [Accepted: 11/01/2018] [Indexed: 11/23/2022]
Abstract
Papaya leaf curl virus (PaLCuV) is a begomovirus (genus Begomovirus; family Geminiviridae) with a monopartite genome that is usually associated with beta- and alphasatellites in plants. Geminiviruses are DNA viruses with small circular genomes that occur as minichromosomes in the nucleus and are susceptible to post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS). Transient expression of the PaLCuV V2 (PV2) protein together with the green fluorescent protein (GFP) in Nicotiana benthamiana resulted in enhanced levels of GFP fluorescence and GFP mRNA, indicative of suppression of PTGS. Expression of PV2 from a Potato virus X vector restored GFP expression in N. benthamiana plants harbouring a transcriptionally silenced GFP transgene, indicative of suppression of TGS. The results show that the PV2 protein encoded by PaLCuV has both suppressor of PTGS and TGS activity and is an important factor in overcoming host RNA-silencing based defenses.
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Affiliation(s)
- Muhammad Mubin
- Virology Lab, Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad 38000, Pakistan; Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan.
| | - Rob W Briddon
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan
| | - Shahid Mansoor
- Agricultural Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Jhang Road, Faisalabad, Pakistan
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Yang Y, Liu T, Shen D, Wang J, Ling X, Hu Z, Chen T, Hu J, Huang J, Yu W, Dou D, Wang MB, Zhang B. Tomato yellow leaf curl virus intergenic siRNAs target a host long noncoding RNA to modulate disease symptoms. PLoS Pathog 2019; 15:e1007534. [PMID: 30668603 PMCID: PMC6366713 DOI: 10.1371/journal.ppat.1007534] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 02/07/2019] [Accepted: 12/16/2018] [Indexed: 11/19/2022] Open
Abstract
Tomato yellow leaf curl virus (TYLCV) and its related begomoviruses cause fast-spreading diseases in tomato worldwide. How this virus induces diseases remains largely unclear. Here we report a noncoding RNA-mediated model to elucidate the molecular mechanisms of TYLCV-tomato interaction and disease development. The circular ssDNA genome of TYLCV contains a noncoding intergenic region (IR), which is known to mediate viral DNA replication and transcription in host cells, but has not been reported to contribute directly to viral disease development. We demonstrate that the IR is transcribed in dual orientations during plant infection and confers abnormal phenotypes in tomato independently of protein-coding regions of the viral genome. We show that the IR sequence has a 25-nt segment that is almost perfectly complementary to a long noncoding RNA (lncRNA, designated as SlLNR1) in TYLCV-susceptible tomato cultivars but not in resistant cultivars which contains a 14-nt deletion in the 25-nt region. Consequently, we show that viral small-interfering RNAs (vsRNAs) derived from the 25-nt IR sequence induces silencing of SlLNR1 in susceptible tomato plants but not resistant plants, and this SlLNR1 downregulation is associated with stunted and curled leaf phenotypes reminiscent of TYLCV symptoms. These results suggest that the lncRNA interacts with the IR-derived vsRNAs to control disease development during TYLCV infection. Consistent with its possible function in virus disease development, over-expression of SlLNR1 in tomato reduces the accumulation of TYLCV. Furthermore, gene silencing of the SlLNR1 in the tomato plants induced TYLCV-like leaf phenotypes without viral infection. Our results uncover a previously unknown interaction between vsRNAs and host lncRNA, and provide a plausible model for TYLCV-induced diseases and host antiviral immunity, which would help to develop effective strategies for the control of this important viral pathogen.
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Affiliation(s)
- Yuwen Yang
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Tingli Liu
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Danyu Shen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jinyan Wang
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xitie Ling
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Zhongze Hu
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Tianzi Chen
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Jieli Hu
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Junyu Huang
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Wengui Yu
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
- * E-mail: (DD); (MBW); (BZ)
| | - Ming-Bo Wang
- CSIRO Plant Industry, Canberra, Australia
- * E-mail: (DD); (MBW); (BZ)
| | - Baolong Zhang
- Provincial Key Laboratory of Agrobiology, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- * E-mail: (DD); (MBW); (BZ)
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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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Calil IP, Quadros IPS, Araújo TC, Duarte CEM, Gouveia-Mageste BC, Silva JCF, Brustolini OJB, Teixeira RM, Oliveira CN, Milagres RWMM, Martins GS, Chory J, Reis PAB, Machado JPB, Fontes EPB. A WW Domain-Containing Protein Forms Immune Nuclear Bodies against Begomoviruses. MOLECULAR PLANT 2018; 11:1449-1465. [PMID: 30296599 DOI: 10.1016/j.molp.2018.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 08/27/2018] [Accepted: 09/28/2018] [Indexed: 05/23/2023]
Abstract
The bipartite begomoviruses (Geminiviridae family), which are DNA viruses that replicate in the nucleus of infected cells, encode the nuclear shuttle protein (NSP) to facilitate the translocation of viral DNA from the nucleus to the cytoplasm via nuclear pores. This intracellular trafficking of NSP-DNA complexes is accessorized by the NSP-interacting guanosine triphosphatase (NIG) at the cytosolic side. Here, we report the nuclear redistribution of NIG by AtWWP1, a WW domain-containing protein that forms immune nuclear bodies (NBs) against begomoviruses. We demonstrated that AtWWP1 relocates NIG from the cytoplasm to the nucleus where it is confined to AtWWP1-NBs, suggesting that the NIG-AtWWP1 interaction may interfere with the NIG pro-viral function associated with its cytosolic localization. Consistent with this assumption, loss of AtWWP1 function cuased plants more susceptible to begomovirus infection, whereas overexpression of AtWWP1 enhanced plant resistance to begomovirus. Furthermore, we found that a mutant version of AtWWP1 defective for NB formation was no longer capable of interacting with and relocating NIG to the nucleus and lost its immune function against begomovirus. The antiviral function of AtWWP1-NBs, however, could be antagonized by viral infection that induced either the disruption or a decrease in the number of AtWWP1-NBs. Collectively, these results led us to propose that AtWWP1 organizes nuclear structures into nuclear foci, which provide intrinsic immunity against begomovirus infection.
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Affiliation(s)
- Iara P Calil
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Iana P S Quadros
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Thais C Araújo
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Christiane E M Duarte
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Bianca C Gouveia-Mageste
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - José Cleydson F Silva
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Otávio J B Brustolini
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Ruan M Teixeira
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Cauê N Oliveira
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Rafael W M M Milagres
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Gilberto S Martins
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; Departament of Genetics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Joanne Chory
- Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute of Biological Studies, La Jolla, CA 92037, USA
| | - Pedro A B Reis
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil
| | - Joao Paulo B Machado
- National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; Agronomy Institute, Universidade Federal de Viçosa, Campus Florestal, Florestal, Minas Gerais 35690-000, Brazil.
| | - Elizabeth P B Fontes
- Departament of Biochemistry and Molecular Biology, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil; National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-000, Brazil.
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Wang B, Yang X, Wang Y, Xie Y, Zhou X. Tomato Yellow Leaf Curl Virus V2 Interacts with Host Histone Deacetylase 6 To Suppress Methylation-Mediated Transcriptional Gene Silencing in Plants. J Virol 2018; 92:e00036-18. [PMID: 29950418 PMCID: PMC6146709 DOI: 10.1128/jvi.00036-18] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 06/22/2018] [Indexed: 12/12/2022] Open
Abstract
Cytosine DNA methylation is a conserved epigenetic silencing mechanism that defends against biotic stresses such as geminivirus infection. As a countermeasure, geminiviruses encode proteins that inhibit methylation and transcriptional gene silencing (TGS). Previous studies showed that V2 protein of Tomato yellow leaf curl virus (TYLCV) functions as a TGS suppressor. However, how V2 mediates TGS suppression remains unknown. Here we show that V2 interacts directly with a Nicotiana benthamiana histone deacetylase 6 (NbHDA6), a homolog of Arabidopsis HDA6 (AtHDA6), known to be involved in gene silencing in cooperation with methyltransferase 1 (MET1). NbHDA6 genetically complemented a late-flowering phenotype and restored histone deacetylation of an AtHDA6 mutant. Furthermore, our investigation showed that NbHDA6 displayed histone deacetylase enzymatic activity, which was not inhibited by V2. Genetic analysis revealed that silencing of NbHDA6 expression resulted in enhanced susceptibility to TYLCV infection. In addition, methylation-sensitive PCR and bisulfite sequencing analysis showed that silencing of NbHDA6 expression caused reduced DNA methylation of the viral genome in infected plants. HDA6 was previously shown to recruit and physically interact with MET1 to function in gene silencing. Using competitive pulldown and coimmunoprecipitation assays, we demonstrated that V2 did not interact but competed with NbMET1 for direct binding to NbHDA6. These findings suggest that V2 interacts with host HDA6 and interferes with the recruitment of MET1 by HDA6, resulting in decreased methylation of the viral DNA genome by TGS with a concomitant increase in host susceptibility to TYLCV infection.IMPORTANCE Plants employ repressive viral genome methylation as an epigenetic defense against geminiviruses. In turn, geminiviruses encode proteins that inhibit methylation by TGS. Previous studies showed that TYLCV V2 can efficiently suppress TGS, but the mechanism remains unknown. We showed that V2 interacted with NbHDA6 but did not inhibit its enzymatic activity. As HDA6 is known to be involved in gene silencing in cooperation with MET1, we explored the relationship between V2, NbMET1, and NbHDA6. Our investigation showed that V2 did not interact but competed with NbMET1 for direct binding to NbHDA6. To our knowledge, this is the first report that viral proteins inhibit TGS by interacting with histone deacetylase but not by blocking the methyl cycle. This work provides an additional mechanism for TGS suppression by geminiviruses.
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Affiliation(s)
- Bi Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
- Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, People's Republic of China
| | - Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Yan Xie
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
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Saeed F, Sattar MN, Hameed U, Ilyas M, Haider MS, Hamza M, Mansoor S, Amin I. Infectivity of okra enation leaf curl virus and the role of its V2 protein in pathogenicity. Virus Res 2018; 255:90-94. [PMID: 30009848 DOI: 10.1016/j.virusres.2018.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 07/10/2018] [Accepted: 07/12/2018] [Indexed: 11/16/2022]
Abstract
Cotton crop has been severely affected by multiple begomoviruses in Pakistan and India. In our previous study, we found okra enation leaf curl virus (OELCuV), cotton leaf curl Multan betasatellite (CLCuMuB) and cotton leaf curl Multan alphasatellite (CLCuMuA) infecting cotton in Pakistan. The current study was designed to investigate the infectivity of OELCuV and its ability to trans-replicate non-cognate CLCuMuB. Agro-infectious clones containing the partial tandem repeats of OELCuV and CLCuMuB were constructed and the infectivity assays were carried out through Agrobacterium mediated transformation in the model host species Nicotiana benthamiana under controlled conditions. The results showed that in the inoculated plants OELCuV alone can cause downward curling and yellowing of leaves with thickened veins. However, when co-inoculated with the non-cognate CLCuMuB it could functionally trans-replicate CLCuMuB resulting in a more severe phenotype. The expression of Pre-coat/V2 protein in the N. benthamiana plants through the potato virus X (PVX) system caused localized cell death after severe leaf curling in the infiltrated leaves. The tissue tropism of the virus was associated with the systemic development of a hypersensitive response (HR), which ultimately lead to the plant death. The results indicated the involvement of V2 protein in the pathogenicity of OELCuV and its ability to trigger the host defense machinery. This study also demonstrated the ability of OELCuV to trans-replicate CLCuMuB resulting in typical leaf curl disease symptoms in N. benthamiana.
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Affiliation(s)
- Farah Saeed
- Institute of Agricultural Sciences, Box 540000, University of the Punjab, Lahore, Pakistan
| | | | - Usman Hameed
- Institute of Agricultural Sciences, Box 540000, University of the Punjab, Lahore, Pakistan
| | - Muhammad Ilyas
- School of Plant Sciences, Box 85721, University of Arizona, Tucson, USA
| | - Muhammad Saleem Haider
- Institute of Agricultural Sciences, Box 540000, University of the Punjab, Lahore, Pakistan
| | - Muhammad Hamza
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Box 577, Faisalabad, Pakistan
| | - Shahid Mansoor
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Box 577, Faisalabad, Pakistan
| | - Imran Amin
- National Institute for Biotechnology and Genetic Engineering (NIBGE), Box 577, Faisalabad, Pakistan.
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Ismayil A, Haxim Y, Wang Y, Li H, Qian L, Han T, Chen T, Jia Q, Yihao Liu A, Zhu S, Deng H, Gorovits R, Hong Y, Hanley-Bowdoin L, Liu Y. Cotton Leaf Curl Multan virus C4 protein suppresses both transcriptional and post-transcriptional gene silencing by interacting with SAM synthetase. PLoS Pathog 2018; 14:e1007282. [PMID: 30157283 PMCID: PMC6133388 DOI: 10.1371/journal.ppat.1007282] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 09/11/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022] Open
Abstract
Gene silencing is a natural antiviral defense mechanism in plants. For effective infection, plant viruses encode viral silencing suppressors to counter this plant antiviral response. The geminivirus-encoded C4 protein has been identified as a gene silencing suppressor, but the underlying mechanism of action has not been characterized. Here, we report that Cotton Leaf Curl Multan virus (CLCuMuV) C4 protein interacts with S-adenosyl methionine synthetase (SAMS), a core enzyme in the methyl cycle, and inhibits SAMS enzymatic activity. By contrast, an R13A mutation in C4 abolished its capacity to interact with SAMS and to suppress SAMS enzymatic activity. Overexpression of wild-type C4, but not mutant C4R13A, suppresses both transcriptional gene silencing (TGS) and post-transcriptional gene silencing (PTGS). Plants infected with CLCuMuV carrying C4R13A show decreased levels of symptoms and viral DNA accumulation associated with enhanced viral DNA methylation. Furthermore, silencing of NbSAMS2 reduces both TGS and PTGS, but enhanced plant susceptibility to two geminiviruses CLCuMuV and Tomato yellow leaf curl China virus. These data suggest that CLCuMuV C4 suppresses both TGS and PTGS by inhibiting SAMS activity to enhance CLCuMuV infection in plants.
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Affiliation(s)
- Asigul Ismayil
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yakupjan Haxim
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yunjing Wang
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Huangai Li
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Lichao Qian
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ting Han
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Tianyuan Chen
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qi Jia
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Alexander Yihao Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Songbiao Zhu
- 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
| | - Rena Gorovits
- Institute of Plant Sciences and Genetics in Agriculture, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot, Israel
| | - Yiguo Hong
- Research Centre 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, United States of America
| | - Yule Liu
- MOE Key Laboratory of Bioinformatics, Center for Plant Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
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45
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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: 14] [Impact Index Per Article: 2.3] [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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46
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Rai KK, Rai N, Rai SP. Salicylic acid and nitric oxide alleviate high temperature induced oxidative damage in Lablab purpureus L plants by regulating bio-physical processes and DNA methylation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 128:72-88. [PMID: 29763836 DOI: 10.1016/j.plaphy.2018.04.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/03/2018] [Accepted: 04/21/2018] [Indexed: 06/08/2023]
Abstract
Salicylic acid (SA) and sodium nitroprusside (SNP, NO donor) modulates plant growth and development processes and recent findings have also revealed their involvement in the regulation of epigenetic factors under stress condition. In the present study, some of these factors were comparatively studied in hyacinth bean plants subjected to high temperature (HT) environment (40-42 °C) with and without exogenous application of SA and SNP under field condition. Exogenous application of SA and SNP substantially modulated the growth and biophysical process of hyacinth bean plants under HT environment. Exogenous application of SA and SNP also remarkably regulated the activities of antioxidant enzymes, modulated mRNA level of certain enzymes, improves plant water relation, enhance photosynthesis and thereby increasing plant defence under HT. Coupled restriction enzyme digestion-random amplification (CRED-RA) technique revealed that many methylation changes were "dose dependent" and HT significantly increased DNA damages as evidenced by both increase and decrease in bands profiles, methylation and de-methylation pattern. Thus, the result of the present study clearly shows that exogenous SA and SNP regulates DNA methylation pattern, modulates stress-responsive genes and can impart transient HT tolerance by synchronizing growth and physiological acclimatization of plants, thus narrowing the gaps between physio-biochemical and molecular events in addressing HT tolerance.
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Affiliation(s)
- Krishna Kumar Rai
- Indian Institute of Vegetable Research, Post Box-01, P.O.-Jakhini, Shahanshahpur, Varanasi, 221305, Uttar Pradesh, India; Laboratory of Morphogenesis, Centre of Advance Study in Botany, Department of Botany, Faculty of Science, Banaras Hindu University (BHU), Varanasi, 221005, Uttar Pradesh, India
| | - Nagendra Rai
- Indian Institute of Vegetable Research, Post Box-01, P.O.-Jakhini, Shahanshahpur, Varanasi, 221305, Uttar Pradesh, India
| | - Shashi Pandey Rai
- Laboratory of Morphogenesis, Centre of Advance Study in Botany, Department of Botany, Faculty of Science, Banaras Hindu University (BHU), Varanasi, 221005, Uttar Pradesh, India.
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48
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Basu S, Kumar Kushwaha N, Kumar Singh A, Pankaj Sahu P, Vinoth Kumar R, Chakraborty S. Dynamics of a geminivirus-encoded pre-coat protein and host RNA-dependent RNA polymerase 1 in regulating symptom recovery in tobacco. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:2085-2102. [PMID: 29432546 PMCID: PMC6019014 DOI: 10.1093/jxb/ery043] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/24/2018] [Indexed: 05/21/2023]
Abstract
RNA silencing is an integral part of the cellular defense mechanisms in plants that act against virus infection. However, the specific role of RNA silencing and the interplay between host and virus components during recovery from geminivirus infection remains unknown. Hence, in this study we aimed to examine the mechanism behind the host-specific recovery of Nicotiana tabacum infected with Tomato leaf curl Gujarat virus (ToLCGV). Unlike Tomato leaf curl New Delhi virus (ToLCNDV), ToLCGV infection resulted in symptom remission in N. tabacum, and we found that this was mainly due to cross-talk between the pre-coat protein (encoded by the AV2 ORF) of the virus and the host RNA-silencing component RNA-dependent RNA polymerase 1 (encoded by NtRDR1) of N. tabacum. Moreover, apart from the AV2 mutant, other mutants of ToLCNDV developed severe symptoms on a transgenic NtRDR1-overexpression line of N. benthamiana. In contrast, inoculation with ToLCGV resulted in symptom remission, which was due to enhanced methylation of the ToLCGV promoter. Our study reveals a novel 'arms race' in which the pre-coat protein of ToLCNDV selectively blocks the recovery process through inhibiting host-specific RDR1-mediated antiviral silencing in tobacco.
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Affiliation(s)
- Saumik Basu
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Nirbhay Kumar Kushwaha
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Ashish Kumar Singh
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Pranav Pankaj Sahu
- Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - R Vinoth Kumar
- 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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49
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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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50
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Mei Y, Yang X, Huang C, Zhang X, Zhou X. Tomato leaf curl Yunnan virus-encoded C4 induces cell division through enhancing stability of Cyclin D 1.1 via impairing NbSKη -mediated phosphorylation in Nicotiana benthamiana. PLoS Pathog 2018; 14:e1006789. [PMID: 29293689 PMCID: PMC5766254 DOI: 10.1371/journal.ppat.1006789] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 01/12/2018] [Accepted: 12/04/2017] [Indexed: 12/27/2022] Open
Abstract
The whitefly-transmitted geminiviruses induce severe developmental abnormalities in plants. Geminivirus-encoded C4 protein functions as one of viral symptom determinants that could induce abnormal cell division. However, the molecular mechanism by which C4 contributes to cell division induction remains unclear. Here we report that tomato leaf curl Yunnan virus (TLCYnV) C4 interacts with a glycogen synthase kinase 3 (GSK3)/SHAGGY-like kinase, designed NbSKη, in Nicotiana benthamiana. Pro32, Asn34 and Thr35 of TLCYnV C4 are critical for its interaction with NbSKη and required for C4-induced typical symptoms. Interestingly, TLCYnV C4 directs NbSKη to the membrane and reduces the nuclear-accumulation of NbSKη. The relocalization of NbSKη impairs phosphorylation dependent degradation on its substrate-Cyclin D1.1 (NbCycD1;1), thereby increasing the accumulation level of NbCycD1;1 and inducing the cell division. Moreover, NbSKη-RNAi, 35S::NbCycD1;1 transgenic N. benthamiana plants have the similar phenotype as 35S::C4 transgenic N. benthamiana plants on callus-like tissue formation resulted from abnormal cell division induction. Thus, this study provides new insights into mechanism of how a viral protein hijacks NbSKη to induce abnormal cell division in plants.
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Affiliation(s)
- Yuzhen Mei
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiuling Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changjun Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, United States of America
| | - Xiuren Zhang
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, United States of America
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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