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Hotspot siRNA Confers Plant Resistance against Viral Infection. BIOLOGY 2022; 11:biology11050714. [PMID: 35625441 PMCID: PMC9138956 DOI: 10.3390/biology11050714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary A hallmark of antiviral RNAi is the production of viral siRNA (vsiRNA). Profiling of vsiRNAs indicates that certain hotspot regions of viral genome or transcribed viral RNAs are more prone to RNAi-mediated cleavage. However, the biological relevance of hotspot vsiRNAs to the host innate defence remains to be elucidated. Here, we show that direct targeting a hotspot by synthetic vsiRNA confers plant resistance to virus infection. Hotspot and coldspot vsiRNAs, based on vsiRNA profile of the African cassava mosaic virus (ACMV), were synthesised. However, only the double-stranded hotspot vsiRNA protected plants from ACMV infection with undetectable levels of viral DNA replication and viral mRNA. We further demonstrated that the hotspot vsiRNA-mediated virus resistance had a threshold effect and required an active RDR6. These data show that hotspot vsiRNAs bear a functional significance on antiviral RNAi, suggesting that they may have the potential as exogenous protection agents for controlling destructive plant viral diseases. Abstract A hallmark of antiviral RNA interference (RNAi) is the production of viral small interfering RNA (vsiRNA). Profiling of vsiRNAs indicates that certain regions of viral RNA genome or transcribed viral RNA, dubbed vsiRNA hotspots, are more prone to RNAi-mediated cleavage for vsiRNA biogenesis. However, the biological relevance of hotspot vsiRNAs to the host innate defence against pathogens remains to be elucidated. Here, we show that direct targeting a hotspot by a synthetic vsiRNA confers host resistance to virus infection. Using Northern blotting and RNAseq, we obtained a profile of vsiRNAs of the African cassava mosaic virus (ACMV), a single-stranded DNA virus. Sense and anti-sense strands of small RNAs corresponding to a hotspot and a coldspot vsiRNA were synthesised. Co-inoculation of Nicotiana benthamiana with the double-stranded hotspot siRNA protected plants from ACMV infection, where viral DNA replication and accumulation of viral mRNA were undetectable. The sense or anti-sense strand of this hotspot vsiRNA, and the coldspot vsiRNA in both double-stranded and single-stranded formats possessed no activity in viral protection. We further demonstrated that the hotspot vsiRNA-mediated virus resistance had a threshold effect and required an active RDR6. These data show that hotspot vsiRNAs bear a functional significance on antiviral RNAi, suggesting that they may have the potential as an exogenous protection agent for controlling destructive viral diseases in plants.
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Zhang X, Kang L, Zhang Q, Meng Q, Pan Y, Yu Z, Shi N, Jackson S, Zhang X, Wang H, Tor M, Hong Y. An RNAi suppressor activates in planta virus-mediated gene editing. Funct Integr Genomics 2020; 20:471-477. [PMID: 31848794 DOI: 10.1007/s10142-019-00730-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/10/2019] [Accepted: 11/05/2019] [Indexed: 11/30/2022]
Abstract
RNA-guided CRISPR/Cas9 technology has been developed for gene/genome editing (GE) in organisms across kingdoms. However, in planta delivery of the two core GE components, Cas9 and small guide RNA (sgRNA), often involves time-consuming and labor-intensive production of transgenic plants. Here we show that Foxtail mosaic virus, a monocot- and dicot-infecting potexvirus, can simultaneously express Cas9, sgRNA, and an RNAi suppressor to efficiently induce GE in Nicotiana benthamiana through a transgenic plant-free manner.
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Affiliation(s)
- Xian Zhang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Lihua Kang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Qi Zhang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Qiqi Meng
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Yafei Pan
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Zhiming Yu
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Nongnong Shi
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Stephen Jackson
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick, CV4 7AL, UK
| | - Xinlian Zhang
- Department of Family Medicine and Public Health, Division of Biostatistics & Bioinformatics, University of California San Diego, La Jolla, CA, 92093, USA
| | - Huizhong Wang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China
| | - Mahmut Tor
- Department of Biology, School of Science and the Environment, Worcester-Hangzhou Joint Molecular Plant Health Laboratory, University of Worcester, Worcester, WR2 6AJ, UK
| | - Yiguo Hong
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, China.
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick, CV4 7AL, UK.
- Department of Biology, School of Science and the Environment, Worcester-Hangzhou Joint Molecular Plant Health Laboratory, University of Worcester, Worcester, WR2 6AJ, UK.
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3
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Yuan C, Li H, Qin C, Zhang X, Chen Q, Zhang P, Xu X, He M, Zhang X, Tör M, Xue D, Wang H, Jackson S, He Y, Liu Y, Shi N, Hong Y. Foxtail mosaic virus-induced flowering assays in monocot crops. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3012-3023. [PMID: 32061090 DOI: 10.1093/jxb/eraa080] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/11/2020] [Indexed: 05/04/2023]
Abstract
Virus-induced flowering (VIF) exploits RNA or DNA viruses to express flowering time genes to induce flowering in plants. Such plant virus-based tools have recently attracted widespread attention for their fundamental and applied uses in flowering physiology and in accelerating breeding in dicotyledonous crops and woody fruit-trees. We now extend this technology to a monocot grass and a cereal crop. Using a Foxtail mosaic virus (FoMV)-based VIF system, dubbed FoMViF, we showed that expression of florigenic Flowering Locus T (FT) genes can promote early flowering and spikelet development in proso millet, a C4 grass species with potential as a nutritional food and biofuel resource, and in non-vernalized C3 wheat, a major food crop worldwide. Floral and spikelet/grain induction in the two monocot plants was caused by the virally expressed untagged or FLAG-tagged FT orthologs, and the florigenic activity of rice Hd3a was more pronounced than its dicotyledonous counterparts in proso millet. The FoMViF system is easy to use and its efficacy to induce flowering and early spikelet/grain production is high. In addition to proso millet and wheat, we envisage that FoMViF will be also applicable to many economically important monocotyledonous food and biofuel crops.
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Affiliation(s)
- Chen Yuan
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Hongmei Li
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Cheng Qin
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xian Zhang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Qianqian Chen
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Pengcheng Zhang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xiaorui Xu
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Meiling He
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Xinlian Zhang
- Department of Family Medicine and Public Health, Division of Biostatistics & Bioinformatics, University of California San Diego, La Jolla, CA, USA
| | - Mahmut Tör
- Worcester-Hangzhou Joint Molecular Plant Health Laboratory, School of Science and the Environment, University of Worcester, Worcester, UK
| | - Dawei Xue
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Huizhong Wang
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Stephen Jackson
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry, UK
| | - Yuehui He
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yule Liu
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China
| | - Nongnong Shi
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yiguo Hong
- Research Centre for Plant RNA Signaling and Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- Worcester-Hangzhou Joint Molecular Plant Health Laboratory, School of Science and the Environment, University of Worcester, Worcester, UK
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry, UK
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Maio F, Arroyo-Mateos M, Bobay BG, Bejarano ER, Prins M, van den Burg HA. A Lysine Residue Essential for Geminivirus Replication Also Controls Nuclear Localization of the Tomato Yellow Leaf Curl Virus Rep Protein. J Virol 2019; 93:e01910-18. [PMID: 30842320 PMCID: PMC6498046 DOI: 10.1128/jvi.01910-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/20/2019] [Indexed: 02/07/2023] Open
Abstract
Geminiviruses are single-stranded DNA (ssDNA) viruses that infect a wide range of plants. To promote viral replication, geminiviruses manipulate the host cell cycle. The viral protein Rep is essential to reprogram the cell cycle and then initiate viral DNA replication by interacting with a plethora of nuclear host factors. Even though many protein domains of Rep have been characterized, little is known about its nuclear targeting. Here, we show that one conserved lysine in the N-terminal part of Rep is pivotal for nuclear localization of the Rep protein from Tomato yellow leaf curl virus (TYLCV), with two other lysines also contributing to its nuclear import. Previous work had identified that these residues are essential for Rep from Tomato golden mosaic virus (TGMV) to interact with the E2 SUMO-conjugating enzyme (SCE1). We here show that mutating these lysines leads to nuclear exclusion of TYLCV Rep without compromising its interaction with SCE1. Moreover, the ability of TYLCV Rep to promote viral DNA replication also depends on this highly conserved lysine independently of its role in nuclear import of Rep. Our data thus reveal that this lysine potentially has a broad role in geminivirus replication, but its role in nuclear import and SCE1 binding differs depending on the Rep protein examined.IMPORTANCE Nuclear activity of the replication initiator protein (Rep) of geminiviruses is essential for viral replication. We now define that one highly conserved lysine is important for nuclear import of Rep from three different begomoviruses. To our knowledge, this is the first time that nuclear localization has been mapped for any geminiviral Rep protein. Our data add another key function to this lysine residue, besides its roles in viral DNA replication and interaction with host factors, such as the SUMO E2-conjugating enzyme.
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Affiliation(s)
- Francesca Maio
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Manuel Arroyo-Mateos
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, Málaga, Spain
| | - Benjamin G Bobay
- Duke University NMR Center, Duke University Medical Center, Durham, North Carolina, USA
- Department of Biochemistry, Duke University, Durham, North Carolina, USA
- Department of Radiology, Duke University, Durham, North Carolina, USA
| | - Eduardo R Bejarano
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Departamento Biología Celular, Genética y Fisiología, Universidad de Málaga, Campus Teatinos, Málaga, Spain
| | - Marcel Prins
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
- Keygene N.V., Wageningen, the Netherlands
| | - Harrold A van den Burg
- Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
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5
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Chen W, Zhang X, Fan Y, Li B, Ryabov E, Shi N, Zhao M, Yu Z, Qin C, Zheng Q, Zhang P, Wang H, Jackson S, Cheng Q, Liu Y, Gallusci P, Hong Y. A Genetic Network for Systemic RNA Silencing in Plants. PLANT PHYSIOLOGY 2018; 176:2700-2719. [PMID: 29439213 PMCID: PMC5884585 DOI: 10.1104/pp.17.01828] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/25/2018] [Indexed: 05/20/2023]
Abstract
Non-cell autonomous RNA silencing can spread from cell to cell and over long distances in animals and plants. However, the genetic requirements and signals involved in plant mobile gene silencing are poorly understood. Here, we identified a DICER-LIKE2 (DCL2)-dependent mechanism for systemic spread of posttranscriptional RNA silencing, also known as posttranscriptional gene silencing (PTGS), in Nicotiana benthamiana Using a suite of transgenic DCL RNAi lines coupled with a GFP reporter, we demonstrated that N. benthamiana DCL1, DCL2, DCL3, and DCL4 are required to produce microRNAs and 22, 24, and 21nt small interfering RNAs (siRNAs), respectively. All investigated siRNAs produced in local incipient cells were present at low levels in distal tissues. Inhibition of DCL2 expression reduced the spread of gene silencing, while suppression of DCL3 or DCL4 expression enhanced systemic PTGS. In contrast to DCL4 RNAi lines, DCL2-DCL4 double-RNAi lines developed systemic PTGS similar to that observed in DCL2 RNAi. We further showed that the 21 or 24 nt local siRNAs produced by DCL4 or DCL3 were not involved in long-distance gene silencing. Grafting experiments demonstrated that DCL2 was required in the scion to respond to the signal, but not in the rootstock to produce/send the signal. These results suggest a coordinated DCL genetic pathway in which DCL2 plays an essential role in systemic PTGS in N. benthamiana, while both DCL4 and DCL3 attenuate systemic PTGS. We discuss the potential role of 21, 22, and 24 nt siRNAs in systemic PTGS.
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Affiliation(s)
- Weiwei Chen
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Xian Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yaya Fan
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Bin Li
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Eugene Ryabov
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
| | - Nongnong Shi
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Mei Zhao
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Zhiming Yu
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Cheng Qin
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Qianqian Zheng
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Pengcheng Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Huizhong Wang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Stephen Jackson
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
| | - Qi Cheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yule Liu
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Philippe Gallusci
- UMR EGFV, Bordeaux Sciences Agro, INRA, Université de Bordeaux, 210 Chemin de Leysotte, CS 50008, 33882 Villenave d'Ornon, France
| | - Yiguo Hong
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Warwick CV4 7AL, United Kingdom
- Worcester-Hangzhou Joint Molecular Plant Health Laboratory, Institute of Science and the Environment, University of Worcester, WR2 6AJ, United Kingdom
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6
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Qin C, Chen W, Shen J, Cheng L, Akande F, Zhang K, Yuan C, Li C, Zhang P, Shi N, Cheng Q, Liu Y, Jackson S, Hong Y. A Virus-Induced Assay for Functional Dissection and Analysis of Monocot and Dicot Flowering Time Genes. PLANT PHYSIOLOGY 2017; 174:875-885. [PMID: 28400493 PMCID: PMC5462034 DOI: 10.1104/pp.17.00392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 04/07/2017] [Indexed: 05/20/2023]
Abstract
Virus-induced flowering (VIF) uses virus vectors to express Flowering Locus T (FT) to induce flowering in plants. This approach has recently attracted wide interest for its practical applications in accelerating breeding in crops and woody fruit trees. However, the insight into VIF and its potential as a powerful tool for dissecting florigenic proteins remained to be elucidated. Here, we describe the mechanism and further applications of Potato virus X (PVX)-based VIF in the short-day Nicotiana tabacum cultivar Maryland Mammoth. Ectopic delivery of Arabidopsis (Arabidopsis thaliana) AtFT by PVX/AtFT did not induce the expression of the endogenous FT ortholog NtFT4; however, it was sufficient to trigger flowering in Maryland Mammoth plants grown under noninductive long-day conditions. Infected tobacco plants developed no systemic symptoms, and the PVX-based VIF did not cause transgenerational flowering. We showed that the PVX-based VIF is a much more rapid method to examine the impacts of single amino acid mutations on AtFT for floral induction than making individual transgenic Arabidopsis lines for each mutation. We also used the PVX-based VIF to demonstrate that adding a His- or FLAG-tag to the N or C terminus of AtFT could affect its florigenic activity and that this system can be applied to assay the function of FT genes from heterologous species, including tomato (Solanum lycopersicum) SFT and rice (Oryza sativa) Hd3a Thus, the PVX-based VIF represents a simple and efficient system to identify individual amino acids that are essential for FT-mediated floral induction and to test the ability of mono- and dicotyledonous FT genes and FT fusion proteins to induce flowering.
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Affiliation(s)
- Cheng Qin
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Weiwei Chen
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Jiajia Shen
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Linming Cheng
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Femi Akande
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Ke Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Chen Yuan
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Chunyang Li
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Pengcheng Zhang
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Nongnong Shi
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Qi Cheng
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Yule Liu
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Stephen Jackson
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.)
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.)
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
| | - Yiguo Hong
- Research Centre for Plant RNA Signaling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China (C.Q., W.C., J.S., L.C., K.Z., C.Y., P.Z., N.S., Y.H.);
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China (Q.C.);
- Centre for Plant Biology and MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China (Y.L.); and
- Warwick-Hangzhou RNA Signaling Joint Laboratory, School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK (F.A, C.L., S.J., Y.H.)
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7
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Abstract
Viruses are intracellular pathogens that have evolved efficient strategies for replication and expression of their proteins in the host cells. Geminiviruses - plant viruses with small circular single-stranded DNA genomes - effectively manipulate plant cell processes for viral functions, entailing great potential for biotechnological applications. This potentiality has been realized in the form of protein expression and gene-silencing vectors, and, more recently, vectors for genome editing - a technology that these viruses seem particularly well-suited to facilitate. This insight offers an overview of the biological properties of geminiviruses, with emphasis on those leveraging development of geminivirus-based replicons. It illustrates the basis for engineering geminivirus-based replicons and their applications. Furthermore, it discusses the reported use and future perspectives of geminivirus-based replicons for genome editing.
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Affiliation(s)
- Rosa Lozano-Durán
- Shanghai Center for Plant Stress Biology (PSC), Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai, 201602, China
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8
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Zhou T, Zhang H, Lai T, Qin C, Shi N, Wang H, Jin M, Zhong S, Fan Z, Liu Y, Wu Z, Jackson S, Giovannoni JJ, Rolin D, Gallusci P, Hong Y. Virus-induced gene complementation reveals a transcription factor network in modulation of tomato fruit ripening. Sci Rep 2012; 2:836. [PMID: 23150786 PMCID: PMC3495281 DOI: 10.1038/srep00836] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/12/2012] [Indexed: 11/10/2022] Open
Abstract
Plant virus technology, in particular virus-induced gene silencing, is a widely used reverse- and forward-genetics tool in plant functional genomics. However the potential of virus technology to express genes to induce phenotypes or to complement mutants in order to understand the function of plant genes is not well documented. Here we exploit Potato virus X as a tool for virus-induced gene complementation (VIGC). Using VIGC in tomato, we demonstrated that ectopic viral expression of LeMADS-RIN, which encodes a MADS-box transcription factor (TF), resulted in functional complementation of the non-ripening rin mutant phenotype and caused fruits to ripen. Comparative gene expression analysis indicated that LeMADS-RIN up-regulated expression of the SBP-box (SQUAMOSA promoter binding protein-like) gene LeSPL-CNR, but down-regulated the expression of LeHB-1, an HD-Zip homeobox TF gene. Our data support the hypothesis that a transcriptional network may exist among key TFs in the modulation of fruit ripening in tomato.
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Affiliation(s)
- Tao Zhou
- Warwick HRI and School of Life Science, University of Warwick, Warwick, UK
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9
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Qin C, Shi N, Gu M, Zhang H, Li B, Shen J, Mohammed A, Ryabov E, Li C, Wang H, Liu Y, Osman T, Vatish M, Hong Y. Involvement of RDR6 in short-range intercellular RNA silencing in Nicotiana benthamiana. Sci Rep 2012; 2:467. [PMID: 22737403 PMCID: PMC3381291 DOI: 10.1038/srep00467] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 06/11/2012] [Indexed: 01/02/2023] Open
Abstract
In plants, non-cell autonomous RNA silencing spreads between cells and over long distances. Recent work has revealed insight on the genetic and molecular components essential for cell-to-cell movement of RNA silencing in Arabidopsis. Using a local RNA silencing assay, we report on a distinct mechanism that may govern the short-range (6-10 cell) trafficking of virus-induced RNA silencing from epidermal to neighbouring palisade and spongy parenchyma cells in Nicotiana benthamiana. This process involves a previously unrecognised function of the RNA-dependent RNA polymerase 6 (RDR6) gene. Our data suggest that plants may have evolved distinct genetic controls in intercellular RNA silencing among different types of cells.
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Affiliation(s)
- Cheng Qin
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- These authors contributed equally to this work
| | - Nongnong Shi
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
- These authors contributed equally to this work
| | - Mei Gu
- Clinical Sciences Research Institute, University of Warwick, Coventry CV2 2DX, UK
- These authors contributed equally to this work
| | - Hang Zhang
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
- Chengdu Rongsheng Pharmaceuticals, Chengdu 610041, China
| | - Bin Li
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Jiajia Shen
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Atef Mohammed
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
- Department of Botany, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt
| | - Eugene Ryabov
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
| | - Chunyang Li
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
- Chengdu Rongsheng Pharmaceuticals, Chengdu 610041, China
| | - Huizhong Wang
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yule Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Toba Osman
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
- Department of Botany, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt
| | - Manu Vatish
- Clinical Sciences Research Institute, University of Warwick, Coventry CV2 2DX, UK
| | - Yiguo Hong
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick HRI, University of Warwick, Warwick CV35 9EF, UK
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10
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Bruce G, Gu M, Shi N, Liu Y, Hong Y. Influence of retinoblastoma-related gene silencing on the initiation of DNA replication by African cassava mosaic virus Rep in cells of mature leaves in Nicotiana benthamiana plants. Virol J 2011; 8:561. [PMID: 22204717 PMCID: PMC3286440 DOI: 10.1186/1743-422x-8-561] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 12/28/2011] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Geminiviruses mainly infect terminally differentiated tissues and cells in plants. They need to reprogramme host cellular machinery for DNA replication. This process is thought to be mediated by inactivation of cell-cycle repressor proteins and by induction of host DNA synthesis protein expression through actions of the geminviral replication initiator protein (Rep). FINDINGS Exploiting a Nicotiana benthamiana pOri2 line, which is transformed with a transgene consisting of a direct repeat of the African cassava mosaic virus (ACMV)-replication origin (Ori) flanking a non-viral DNA region, and virus-induced RNA silencing (VIGS), the impact of host gene expression on replication of the ACMV-derived replicon was investigated. The ACMV Rep trans-replicated the viral episomal replicon in leaves of young but not older pOri2 plants. Upon VIGS-mediated down-regulation of N. benthamiana NbRBR1, the retinoblastoma-related protein gene coding for a negative cell-cycle suppressor, recovered the ability of ACMV Rep for trans DNA replication, whereas the silencing of NbPCNA coding for the sliding clamp of DNA polymerase had no effect. CONCLUSIONS These results suggest that the cellular machinery for DNA replication in differentiated tissues of older leaves cannot be reprogrammed by Rep alone but may need other uncharacterised viral and plant factors.
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Affiliation(s)
- Gareth Bruce
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
- Biological Sciences Research Unit, University of Glamorgan, Pontypridd, CF37 1DL Wales, UK
| | - Mei Gu
- Clinical Sciences Research Institute, University of Warwick, Coventry CV2 2DX, UK
| | - Nongnong Shi
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
| | - Yule Liu
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yiguo Hong
- Research Centre for Plant RNA Signalling, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
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11
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Krenz B, Neugart F, Kleinow T, Jeske H. Self-interaction of Abutilon mosaic virus replication initiator protein (Rep) in plant cell nuclei. Virus Res 2011; 161:194-7. [PMID: 21840354 DOI: 10.1016/j.virusres.2011.07.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 07/27/2011] [Accepted: 07/27/2011] [Indexed: 11/30/2022]
Abstract
Geminiviruses replicate their circular single-stranded DNA genome in nuclei of infected plant cells. Their replication initiator proteins (Reps) possess interaction domains for homo- and hetero-oligomerization as shown previously by in vitro studies and yeast two hybrid assays. Here, homo-oligomerization and cellular localization of the Abutilon mosaic virus (AbMV) Rep was analysed with bimolecular fluorescence complementation (BiFC) in epidermal tissues of Nicotiana benthamiana. BiFC revealed that Rep oligomers accumulated within the nucleoplasm, but were excluded from nucleoli as indicated by a nucleoli/cajal body marker. A similar subcellular distribution was observed for Rep fused to full-length cyan fluorescent protein. To examine whether tagged Reps were functionally active, N. benthamiana plants transgenic for a dimeric AbMV DNA B were inoculated with the BiFC expression constructs and nucleic acids were analysed by rolling circle amplification/restriction fragment length polymorphism as well as Southern blot hybridization. The results confirmed that the modified AbMV Rep was able to transreplicate DNA B.
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Affiliation(s)
- Björn Krenz
- Institute of Biology, Dpt. of Molecular Biology and Plant Virology, Pfaffenwaldring 57, University of Stuttgart, D-70550 Stuttgart, Germany
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12
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Sardo L, Lucioli A, Tavazza M, Masenga V, Tavazza R, Accotto GP, Noris E. An RGG sequence in the replication-associated protein (Rep) of Tomato yellow leaf curl Sardinia virus is involved in transcriptional repression and severely impacts resistance in Rep-expressing plants. J Gen Virol 2011; 92:204-9. [PMID: 20943892 DOI: 10.1099/vir.0.025817-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Truncated versions of the replication-associated protein (Rep) of Tomato yellow leaf curl Sardinia virus (TYLCSV) can interfere with various viral functions and the N-terminal 130 aa are sufficient for strongly inhibiting C1-gene transcription and virus replication and confer resistance in transgenic plants. In this work, we analysed the relevance of an RGG sequence at aa 124-126, highly conserved in begomoviruses, in these inhibitory functions as well as in the subcellular localization of Rep. Although no role of this RGG sequence was detected by cell fractionation and immunogold labelling in Rep localization, this sequence appears relevant for the transcriptional control of the C1-gene and for the inhibition of viral replication and dramatically impacts resistance in transgenic plants. These results are discussed in the context of the model of Rep-mediated resistance against TYLCSV.
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Affiliation(s)
- Luca Sardo
- Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, 10135 Torino, Italy
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13
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Shi Y, Ryabov EV, van Wezel R, Li C, Jin M, Wang W, Fan Z, Hong Y. Suppression of local RNA silencing is not sufficient to promote cell-to-cell movement of Turnip crinkle virus in Nicotiana benthamiana. PLANT SIGNALING & BEHAVIOR 2009; 4:15-22. [PMID: 19568335 PMCID: PMC2634062 DOI: 10.4161/psb.4.1.7573] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 12/09/2008] [Indexed: 05/19/2023]
Abstract
The biological relationship between suppression of RNA silencing and virus movement poses an intriguing question in virus-plant interactions. Here, we have used a local RNA silencing assay, based on a movement-deficient Turnip crinkle virus TCV/GFPDeltaCP, to investigate the influence of silencing suppression by three different viral suppressors: the TCV 38K coat protein (CP), the 126K protein of Tobacco mosaic virus (TMV), and P19 of Tomato bushy stunt virus (TBSV) on cell-to-cell movement and long-distance spread of TCV/GFPDeltaCP. First, we found that TCV CP blocked the induction of local RNA silencing, but failed to support virus trafficking in silencing-suppressed transgenic plants, although it acted as a functional movement protein in non-transformed plants. Second, we demonstrated that the TMV 126K suppressor inhibited TCV/GFPDeltaCP-mediated RNA silencing, but did not facilitate intercellular spread of the chimaeric carmovirus. However, TMV and TMVDeltaCP prevented the initiation of RNA silencing by TCV/GFPDeltaCP and caused TCV/GFPDeltaCP to move between cells, although only TMV supported its long-distance spread. Third, TBSV P19 functioned as a movement protein for TCV/GFPDeltaCP and as a silencing suppressor in non-transformed and silencing-suppressed transgenic plants. We further identified three types of mutant P19 proteins that possessed no or varied functionality in silencing suppression and in the facilitation of carmovirus movement. These results suggest that, although suppression of local RNA silencing is essential for the maintenance of viral RNA, recovery of cell-to-cell movement and long-distance spread of movement-deficient carmoviruses is not a direct consequence of such silencing suppression.
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Affiliation(s)
- Yan Shi
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology; China Agricultural University; Beijing China
| | - Eugene V Ryabov
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
| | - Rene van Wezel
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
| | - Chunyang Li
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
| | - Mingfei Jin
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
- School of Life Science; East China Normal University; Shanghai China
| | - Wenjing Wang
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
| | - Zaifeng Fan
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology; China Agricultural University; Beijing China
| | - Yiguo Hong
- Warwick HRI; University of Warwick; Warwick, Wellesbourne UK
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14
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Jin M, Li C, Shi Y, Ryabov E, Huang J, Wu Z, Fan Z, Hong Y. A single amino acid change in a geminiviral Rep protein differentiates between triggering a plant defence response and initiating viral DNA replication. J Gen Virol 2008; 89:2636-2641. [PMID: 18796734 DOI: 10.1099/vir.0.2008/001966-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We have devised an in planta system for functional analysis of the replication-associated protein (Rep) of African cassava mosaic virus (ACMV). Using this assay and PCR-based random mutagenesis, we have identified an ACMV Rep mutant that failed to trigger the hypersensitive response (HR), but had an enhanced ability to initiate DNA replication. The mutant Rep-green fluorescent protein (GFP) fusion protein was localized to the nucleus. Sequence analysis showed that the mutated Rep gene had three nucleotide changes (A6-->T, T375-->G and G852-->A); only the A6-->T transversion resulted in an amino acid substitution (Arg to Ser), which is at the second residue in the 358 amino acid ACMV Rep protein. Our results indicate that a single amino acid can alter the differential ability of ACMV Rep to trigger the host-mediated HR defence mechanism and to initiate viral DNA replication. The implications of this finding are discussed in the context of plant-virus interactions.
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Affiliation(s)
- Mingfei Jin
- School of Life Science, East China Normal University, Shanghai 200062, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Chunyang Li
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Yan Shi
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100094, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Eugene Ryabov
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Jing Huang
- School of Life Science, East China Normal University, Shanghai 200062, PR China
| | - Zirong Wu
- School of Life Science, East China Normal University, Shanghai 200062, PR China
| | - Zaifeng Fan
- Department of Plant Pathology and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100094, PR China.,Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
| | - Yiguo Hong
- Warwick HRI, University of Warwick, Wellesbourne, Warwick CV35 9EF, UK
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15
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van der Walt E, Palmer KE, Martin DP, Rybicki EP. Viable chimaeric viruses confirm the biological importance of sequence specific maize streak virus movement protein and coat protein interactions. Virol J 2008; 5:61. [PMID: 18489800 PMCID: PMC2430021 DOI: 10.1186/1743-422x-5-61] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Accepted: 05/20/2008] [Indexed: 11/29/2022] Open
Abstract
Background A variety of interactions between up to three different movement proteins (MPs), the coat protein (CP) and genomic DNA mediate the inter- and intra-cellular movement of geminiviruses in the genus Begomovirus. Although movement of viruses in the genus Mastrevirus is less well characterized, direct interactions between a single MP and the CP of these viruses is also clearly involved in both intra- and intercellular trafficking of virus genomic DNA. However, it is currently unknown how specific these MP-CP interactions are, nor how disruption of these interactions might impact on virus viability. Results Using chimaeric genomes of two strains of Maize streak virus (MSV) we adopted a genetic approach to investigate the gross biological effects of interfering with interactions between virus MP and CP homologues derived from genetically distinct MSV isolates. MP and CP genes were reciprocally exchanged, individually and in pairs, between maize (MSV-Kom)- and Setaria sp. (MSV-Set)-adapted isolates sharing 78% genome-wide sequence identity. All chimaeras were infectious in Zea mays c.v. Jubilee and were characterized in terms of symptomatology and infection efficiency. Compared with their parental viruses, all the chimaeras were attenuated in symptom severity, infection efficiency, and the rate at which symptoms appeared. The exchange of individual MP and CP genes resulted in lower infection efficiency and reduced symptom severity in comparison with exchanges of matched MP-CP pairs. Conclusion Specific interactions between the mastrevirus MP and CP genes themselves and/or their expression products are important determinants of infection efficiency, rate of symptom development and symptom severity.
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Affiliation(s)
- Eric van der Walt
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa.
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16
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Choudhury NR, Malik PS, Singh DK, Islam MN, Kaliappan K, Mukherjee SK. The oligomeric Rep protein of Mungbean yellow mosaic India virus (MYMIV) is a likely replicative helicase. Nucleic Acids Res 2006; 34:6362-77. [PMID: 17142233 PMCID: PMC1669733 DOI: 10.1093/nar/gkl903] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Geminiviruses replicate by rolling circle mode of replication (RCR) and the viral Rep protein initiates RCR by the site-specific nicking at a conserved nonamer (TAATATT downward arrow AC) sequence. The mechanism of subsequent steps of the replication process, e.g. helicase activity to drive fork-elongation, etc. has largely remained obscure. Here we show that Rep of a geminivirus, namely, Mungbean yellow mosaic India virus (MYMIV), acts as a replicative helicase. The Rep-helicase, requiring > or =6 nt space for its efficient activity, translocates in the 3'-->5' direction, and the presence of forked junction in the substrate does not influence the activity to any great extent. Rep forms a large oligomeric complex and the helicase activity is dependent on the oligomeric conformation ( approximately 24mer). The role of Rep as a replicative helicase has been demonstrated through ex vivo studies in Saccharomyces cerevisiae and in planta analyses in Nicotiana tabacum. We also establish that such helicase activity is not confined to the MYMIV system alone, but is also true with at least two other begomoviruses, viz., Mungbean yellow mosaic virus (MYMV) and Indian cassava mosaic virus (ICMV).
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Affiliation(s)
| | | | | | | | | | - Sunil Kumar Mukherjee
- To whom correspondence should be addressed. Tel: +91 11 26189358; Fax: +91 11 26162316;
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17
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Hefferon KL, Moon YS, Fan Y. Multi-tasking of nonstructural gene products is required for bean yellow dwarf geminivirus transcriptional regulation. FEBS J 2006; 273:4482-94. [PMID: 16972938 DOI: 10.1111/j.1742-4658.2006.05454.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mastreviridae, of the family geminiviridae, possess a monopartite genome and are transmitted by leafhoppers. Bean yellow dwarf dirus (BeYDV) is a mastrevirus which originated from South Africa and infects dicoyledenous plants, a feature unusual for mastreviridae. Previously, the nonstructural proteins Rep and RepA were examined with respect to their independent roles in BeYDV replication. This was achieved by placing both gene products under independent constitutive promoter control and examining their effects on replication-competent constructs. In the current study, Rep and RepA are examined further for their roles in regulating BeYDV gene expression using a series of replication-incompetent constructs. While both Rep and RepA are found to behave as equally potent inhibitors of complementary-sense gene expression, they differ considerably with respect to their abilities to transactivate virion-sense gene expression. Furthermore, RepA is identified as playing more than one role in this transactivation process. A nuclear localization domain is identified in Rep which is absent in RepA, and Rep-RepA interactions are examined under in vivo conditions. The study concludes with an investigation into the expression strategies of the BeYDV capsid protein.
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18
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Morilla G, Castillo AG, Preiss W, Jeske H, Bejarano ER. A versatile transreplication-based system to identify cellular proteins involved in geminivirus replication. J Virol 2006; 80:3624-33. [PMID: 16537630 PMCID: PMC1440397 DOI: 10.1128/jvi.80.7.3624-3633.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 12/17/2005] [Indexed: 01/18/2023] Open
Abstract
A versatile green fluorescent protein (GFP) expression cassette containing the replication origins of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV) is described. Transgenic Nicotiana benthamiana plants containing one copy of the cassette stably integrated into their genome were superinfected with TYLCSV, which mobilized and replicated the cassette as an episomal replicon. The expression of the reporter gene (the GFP gene) was thereby modified. Whereas GFP fluorescence was dimmed in the intercostal areas, an increase of green fluorescence in veins of all leaves placed above the inoculation site, as well as in transport tissues of roots and stems, was observed. The release of episomal trans replicons from the transgene and the increase in GFP expression were dependent on the cognate geminiviral replication-associated protein (Rep) and required interaction between Rep and the intergenic region of TYLCSV. This expression system is able to monitor the replication status of TYLCSV in plants, as induction of GFP expression is only produced in those tissues where Rep is present. To further confirm this notion, the expression of a host factor required for geminivirus replication, the proliferating cellular nuclear antigen (PCNA) was transiently silenced. Inhibition of PCNA prevented GFP induction in veins and reduced viral DNA. We propose that these plants could be widely used to easily identify host factors required for geminivirus replication by virus-induced gene silencing.
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Affiliation(s)
- Gabriel Morilla
- Unidad de Genética, Departamento de Biología Celular, Genética, y Fisiología, Universidad de Málaga, 29071 Málaga, Spain
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19
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Vega-Arreguín JC, Timchenko T, Gronenborn B, Ramírez BC. A functional histidine-tagged replication initiator protein: implications for the study of single-stranded DNA virus replication in planta. J Virol 2005; 79:8422-30. [PMID: 15956586 PMCID: PMC1143747 DOI: 10.1128/jvi.79.13.8422-8430.2005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Replication initiation of nanoviruses, plant viruses with a multipartite circular single-stranded DNA genome, is triggered by the master Rep (M-Rep) protein. To enable the study of interactions between M-Rep and viral or host factors involved in replication, we designed oligohistidine-tagged variants of the nanovirus Faba bean necrotic yellows virus (FBNYV) M-Rep protein that allow affinity purification of enzymatically active M-Rep from plant tissue. The tagged M-Rep protein was able to initiate replication of its cognate and other FBNYV DNAs in Nicotiana benthamiana leaf disks and plants. The replicon encoding the tagged M-Rep protein multiplied and moved systemically in FBNYV-infected Vicia faba plants and was transmitted by the aphid vector of the virus. Using the tagged M-Rep protein, we demonstrated the in planta interaction between wild-type M-Rep and its tagged counterpart. Such a tagged and fully functional replication initiator protein will have bearings on the isolation of protein complexes from plants.
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Affiliation(s)
- Julio C Vega-Arreguín
- Institut des Sciences du Végétal, CNRS, Avenue de la Terrasse, Bât. 23, 91198 Gif sur Yvette Cedex, France
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Manske U, Schiemann J. Development and assessment of a potato virus X-based expression system with improved biosafety. ENVIRONMENTAL BIOSAFETY RESEARCH 2005; 4:45-57. [PMID: 16209135 DOI: 10.1051/ebr:2005011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Over the last decade, plant virus-based vectors have been developed and successfully exploited for high-yield production of heterologous proteins in plants. However, widespread application of recombinant viruses raises concerns about possible risks to the environment. One of the primary safety issues that must be considered is the uncontrolled spread of the genetically engineered virus from experimental plants to susceptible weeds or crops. Using a movement-deficient Potato virus X (PVX)-based transient gene expression vector which harbors the beta-glucuronidase (gus) gene, we established a plant viral expression system that provides containment of the recombinant virus and allows for safe and efficient protein production. By deletion of the viral 25k movement protein gene, systemic spread of the modified virus in non-transgenic Nicotiana benthamiana plants was successfully inhibited. In transgenic N. benthamiana plants expressing the 25K viral movement protein, this deficiency was complemented, thus resulting in systemic infection with the movement-deficient virus. While no differences in virus spread and accumulation were observed compared to infection caused by wild-type PVX in non-transgenic plants, the movement protein transgenic plants exhibited none of the normal symptoms of viral infection. Several biosafety aspects were investigated including the potential for recombination between the defective virus and the movement protein transgene, as well as complementation effects in non-transgenic plants doubly infected with the defective and the wild-type virus. Furthermore, the applicability of the safety system for the production of heterologous proteins was evaluated with gus as a model gene. With respect to the stability of the gus insert and the expression level of the GUS protein, there were no differences between the novel system developed and the conventional PVX-based expression system.
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Affiliation(s)
- Ulrike Manske
- Federal Biological Research Center for Agriculture and Forestry, Institute for Plant Virology, Microbiology and Biosafety, Messeweg 11-12, D-38104 Braunschweig, Germany
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Bagewadi B, Chen S, Lal SK, Choudhury NR, Mukherjee SK. PCNA interacts with Indian mung bean yellow mosaic virus rep and downregulates Rep activity. J Virol 2004; 78:11890-903. [PMID: 15479830 PMCID: PMC523298 DOI: 10.1128/jvi.78.21.11890-11903.2004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Proliferative cell nuclear antigen (PCNA), a conserved plant protein as well as an important replication factor, is induced in response to geminivirus infection in the resting cells of the phloem tissues. The biochemical role of PCNA in rolling circle replication (RCR) of geminivirus DNA has not been explored in detail. The initiation of RCR of the bipartite genome of a geminivirus, Indian mung bean yellow mosaic virus (IMYMV), is mainly controlled by viral protein Rep (or AL1 or AC1). The role of host PCNA in RCR of IMYMV was revealed by studying the physical and functional interactions between recombinant PCNA and recombinant IMYMV Rep. Pea nuclear PCNA as well as recombinant pea PCNA showed binding to recombinant Rep in experiments involving both affinity chromatography and yeast two-hybrid approaches. The contacting amino acid residues of PCNA seemed to be present throughout a wide region of the trimeric protein, while those of Rep appeared to be localized only in the middle part of the protein. The site-specific nicking-closing activity and the ATPase function of IMYMV Rep were impaired by PCNA. These observations lead to interesting speculations about the control of viral RCR and dynamic profiles of protein-protein interactions at the RCR origin of the geminiviruses.
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Affiliation(s)
- Basavaraj Bagewadi
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
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