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Ye X, Ding D, Chen Y, Liu C, Li Z, Lou B, Zhou Y. Identification of RNA silencing suppressor encoded by citrus chlorotic dwarf-associated virus. Front Microbiol 2024; 15:1328289. [PMID: 38333582 PMCID: PMC10850569 DOI: 10.3389/fmicb.2024.1328289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction Citrus chlorotic dwarf-associated virus (CCDaV) is an economically important citrus virus associated with leaf curling, deformation, and chlorosis found in China. Plants have evolved RNA silencing to defend against viral infections; however, the mechanism by which CCDaV suppresses RNA silencing in citrus remains unknown. Methods Six proteins encoded by CCDaV were ectopically expressed in Nicotiana benthamiana 16c using the pCHF3 vector to identify RNA-silencing suppression activities. Results V2 protein encoded by CCDaV suppressed local RNA silencing and systemic RNA silencing triggered by GFP RNA, but did not impede short-distance movement of the RNA silencing signal in N. benthamiana 16c. GFP fluorescence observations showed that the ability of V2 protein to suppress RNA silencing was weaker than tomato bushy stunt virus P19. Deletion analysis showed that the putative nuclear localization signal (NLS, 25-54 aa) was involved in the RNA silencing suppression activity of V2 protein. Furthermore, V2 protein cannot block dsRNA-triggered RNA silencing. The subcellular localization assay suggested that V2 protein was localized to nucleus of N. benthamiana. Conclusion Overall, the results of this study demonstrate that CCDaV-V2 acts as an activity of silencing suppression. This is the first reported RNA-silencing suppressor encoded by Citlodavirus and will be valuable in revealing the molecular mechanism of CCDaV infection.
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Affiliation(s)
- Xiao Ye
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Dongdong Ding
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Yuan Chen
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Chuang Liu
- Lemon Industry Development Center, Anyue, Sichuan, China
| | - Zhongan Li
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
| | - Binghai Lou
- Guangxi Citrus Breeding and Cultivation Research Center of Engineering Technology/Guangxi Academy of Specialty Crops, Guilin, Guangxi, China
| | - Yan Zhou
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City/Citrus Research Institute, Southwest University, Chongqing, China
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Han TT, Tang JX, Fang M, Zhang P, Han PY, Yin ZN, Ma Y, Zhang J, Lu QY. Two genes encoded by mulberry crinkle leaf virus (MCLV): The V4 gene enhances viral replication, and the V5 gene is needed for MCLV infection in Nicotiana benthamiana. Virus Res 2024; 339:199288. [PMID: 38043724 PMCID: PMC10751690 DOI: 10.1016/j.virusres.2023.199288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 11/21/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
Mulberry crinkle leaf virus (MCLV) is a member of the genus Mulcrilevirus, family Geminiviridae. The expression and functions of the V4 and V5 genes encoded by the MCLV genome remain unknown. Here, we confirmed the expression of V4 and V5 by analyzing the V4 and V5 mRNAs and the promoter activity of individual ORFs upstream sequences. The functions of V4 and V5 were investigated by constructing Agrobacterium-mediated infectious clones of wild-type MCLV variant П (MCLV vII), MCLVwt and MCLV vП mutants, such as MCLVmV4 (start codon of V4 ORF mutated), MCLVdV4 (5'-end partial deletion of V4 ORF sequence) and MCLVmV5 (V5 ORF start codon mutated). Although MCLVwt, MCLVmV4, and MCLVdV4 could infect natural host mulberry and experimental tomato plants systematically, the replication of the MCLVmV4 and MCLVdV4 genomes was obviously reduced compared to MCLVwt in both mulberry and tomato plants. MCLV vП expressing V5 could infect Nicotiana benthamiana plants systematically, but MCLVmV5 could not, implying that V5 is needed for MCLV vП to infect N. benthamiana plants. Taken together, V4 is involved in replication of the MCLV genome in host plants, and V5 potentially might extend the host range. Our findings lay a foundation for in-depth insight into the functions of MCLV-encoded proteins and provide a novel perspective for the subsequent study of MCLV-host plant interactions.
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Affiliation(s)
- Tao-Tao Han
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Jia-Xuan Tang
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Miao Fang
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Peng Zhang
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Pei-Yu Han
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Zhen-Ni Yin
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Yu Ma
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China
| | - Jian Zhang
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China; Key Laboratory of Genetic Improvement of Silkworm and Mulberry, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, Jiangsu 212100, China
| | - Quan-You Lu
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212100, China; Key Laboratory of Genetic Improvement of Silkworm and Mulberry, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang, Jiangsu 212100, China.
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Solovyev AG, Morozov SY. Uncovering Plant Virus Species Forming Novel Provisional Taxonomic Units Related to the Family Benyviridae. Viruses 2022; 14:v14122680. [PMID: 36560684 PMCID: PMC9781952 DOI: 10.3390/v14122680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 12/05/2022] Open
Abstract
Based on analyses of recent open-source data, this paper describes novel horizons in the diversity and taxonomy of beny-like viruses infecting hosts of the plant kingdom (Plantae or Archaeplastida). First, our data expand the known host range of the family Benyviridae to include red algae. Second, our phylogenetic analysis suggests that the evolution of this virus family may have involved cross-kingdom host change events and gene recombination/exchanges between distant taxa. Third, the identification of gene blocks encoding known movement proteins in beny-like RNA viruses infecting non-vascular plants confirms other evidence that plant virus genomic RNAs may have acquired movement proteins simultaneously or even prior to the evolutionary emergence of the plant vascular system. Fourth, novel data on plant virus diversity highlight that molecular evolution gave rise to numerous provisional species of land-plant-infecting viruses, which encode no known potential movement genetic systems.
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Affiliation(s)
- Andrey G. Solovyev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
- All Russia Research Institute of Agricultural Biotechnology, 127550 Moscow, Russia
| | - Sergey Y. Morozov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Russia
- Department of Virology, Biological Faculty, Moscow State University, 119234 Moscow, Russia
- Correspondence: ; Tel.: +7-(495)-9393198
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Wu H, Liu M, Kang B, Liu L, Hong N, Peng B, Gu Q. AC5 protein encoded by squash leaf curl China virus is an RNA silencing suppressor and a virulence determinant. Front Microbiol 2022; 13:980147. [PMID: 36060769 PMCID: PMC9437540 DOI: 10.3389/fmicb.2022.980147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/05/2022] [Indexed: 11/26/2022] Open
Abstract
Squash leaf curl China virus (SLCCNV) is a bipartite Begomovirus. The function of the protein AC5, which is encoded by SLCCNV, is unknown. Here, we confirmed that the 172-amino acids (aa) long AC5 protein of SLCCNV could suppress single-stranded RNA but not double-stranded RNA-induced post-transcriptional gene silencing (PTGS). Furthermore, we determined that the C-terminal domain (96–172 aa) of the AC5 protein was responsible for RNA silencing suppressor (RSS) activity via deletion mutant analysis. The AC5 protein can reverse GFP silencing and inhibit systemic silencing of GFP by interfering with the systemic spread of the GFP silencing signal. The SLCCNV AC5 protein was localized to both the nucleus and cytoplasm of Nicotiana benthamiana cells. Furthermore, deletion analysis showed that the putative nuclear localization signal (NLS, 102–155 aa) was crucial for the RNA silencing suppression activity of AC5. In addition, the AC5 protein elicited a hypersensitive response and enhanced potoao virus X (PVX) RNA accumulation in infected N. benthamiana plants. Using the infectious clones of the SLCCNV and SLCCNV-AC5 null mutants, mutational analysis confirmed that knockout of the AC5 gene abolished SLCCNV-induced leaf curl symptoms, showing SLCCNV AC5 is also a virulence determinant.
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Affiliation(s)
- Huijie Wu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Mei Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Baoshan Kang
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Liming Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Ni Hong
- College of Plant Science and Technology, Huazhong Agricultural University/Key Lab of Plant Pathology of Hubei Province, Wuhan, China
| | - Bin Peng
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- Bin Peng,
| | - Qinsheng Gu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
- *Correspondence: Qinsheng Gu,
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Lu QY, Ma Y, Smith WK, Yu J, Cheng YY, Zhang P, Han TT. The Identification of Tautoneura mori as the Vector of Mulberry Crinkle Leaf Virus and the Infectivity of Infectious Clones in Mulberry. PHYTOPATHOLOGY 2022; 112:435-440. [PMID: 34261340 DOI: 10.1094/phyto-03-21-0094-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mulberry crinkle leaf virus (MCLV) is a novel geminivirus identified from mulberry. The pathogenicity and natural vector transmission of MCLV remain unknown. Here, infectious clones consisting of the complete tandem dimeric genome of MCLV in a binary vector were constructed and agroinoculated into young mulberry plants. The results showed that the infectious clones of MCLV were systemically infectious in mulberry, but the infected mulberry plants did not show any virus infection-like symptoms. The natural transmission vectors of MCLV were also identified from possible vector insects occurring on the MCLV-infected mulberry plants. The vector ability of Tautoneura mori was identified through an inoculation assay. Three of 21 (14.3%) plants inoculated with T. mori collected from MCLV-infected mulberry plants grown naturally were found to be MCLV-positive 50 days postinoculation. These MCLV-positive mulberry plants did not show any virus infection-like symptoms. Collectively, these results suggest that MCLV is infectious to mulberry plants but, by itself, does not induce infection symptoms. The leafhopper T. mori was experimentally determined to be a transmission vector of MCLV for the first time.
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Affiliation(s)
- Quan-You Lu
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
- Key Laboratory of Genetic Improvement of Silkworm and Mulberry, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018 Jiangsu, China
| | - Yu Ma
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
| | - William Kojo Smith
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
| | - Jing Yu
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
| | - Yong-Yuan Cheng
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
| | - Peng Zhang
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
| | - Tao-Tao Han
- College of Biotechnology, Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212018 Jiangsu, China
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Teixeira RM, Ferreira MA, Raimundo GAS, Fontes EPB. Geminiviral Triggers and Suppressors of Plant Antiviral Immunity. Microorganisms 2021; 9:microorganisms9040775. [PMID: 33917649 PMCID: PMC8067988 DOI: 10.3390/microorganisms9040775] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/26/2021] [Accepted: 03/26/2021] [Indexed: 12/19/2022] Open
Abstract
Geminiviruses are circular single-stranded DNA plant viruses encapsidated into geminate virion particles, which infect many crops and vegetables and, hence, represent significant agricultural constraints worldwide. To maintain their broad-range host spectrum and establish productive infection, the geminiviruses must circumvent a potent plant antiviral immune system, which consists of a multilayered perception system represented by RNA interference sensors and effectors, pattern recognition receptors (PRR), and resistance (R) proteins. This recognition system leads to the activation of conserved defense responses that protect plants against different co-existing viral and nonviral pathogens in nature. Furthermore, a specific antiviral cell surface receptor signaling is activated at the onset of geminivirus infection to suppress global translation. This review highlighted these layers of virus perception and host defenses and the mechanisms developed by geminiviruses to overcome the plant antiviral immunity mechanisms.
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