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Li L, Wang G, Zhang Y, Wang W, Zhu Y, Lyu Y, Wang Y, Zhang Y, Hong N. The functions of triple gene block proteins and coat protein of apple stem pitting virus in viral cell-to-cell movement. MOLECULAR PLANT PATHOLOGY 2024; 25:e13392. [PMID: 37837244 PMCID: PMC10782654 DOI: 10.1111/mpp.13392] [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: 07/03/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023]
Abstract
Apple stem pitting virus is a species in the genus Foveavirus in the family Betaflexiviridae. Apple stem pitting virus (ASPV) commonly infects apple and pear plants grown worldwide. In this study, by integrating bimolecular fluorescence complementation, split-ubiquitin-based membrane yeast two-hybrid, and Agrobacterium-mediated expression assays, the interaction relationships and the subcellular locations of ASPV proteins TGBp1-3 and CP in Nicotiana benthamiana leaf cells were determined. Proteins CP, TGBp1, TGBp2, and TGBp3 were self-interactable, and TGBp2 played a role in the formation of perinuclear viroplasm and enhanced the colocalization of TGBp3 with CP and TGBp1. We found that the plant microfilament and endoplasmic reticulum structures were involved in the production of TGBp3 and TGBp2 vesicles, and their disruption decreased the virus accumulation level in the systemic leaves. The TGBp3 motile vesicles functioned in delivering the viral ribonucleoprotein complexes to the plasma membrane. Two cysteine residues at sites 35 and 49 of the TGBp3 sorting signal were necessary for the diffusion of TGBp3-marked vesicles. Furthermore, our results revealed that TGBp1, TGBp2, and CP could increase plasmodesmal permeability and move to the adjacent cells. This study demonstrates an interaction network and a subcellular location map of four ASPV proteins and for the first time provides insight into the functions of these proteins in the movement of a foveavirus.
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Affiliation(s)
- Liu Li
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Guoping Wang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Yue Zhang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
| | - Wenjun Wang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Yiting Zhu
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Yuzhuo Lyu
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Yanxiang Wang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Yongle Zhang
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
| | - Ni Hong
- Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural CropsHuazhong Agricultural UniversityWuhanChina
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Long-Term Potato Virus X (PVX)-Based Transient Expression of Recombinant GFP Protein in Nicotiana benthamiana Culture In Vitro. PLANTS 2021; 10:plants10102187. [PMID: 34685995 PMCID: PMC8537016 DOI: 10.3390/plants10102187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 11/17/2022]
Abstract
Plant molecular farming has a great potential to produce valuable proteins. Transient expression technology provides high yields of recombinant proteins in greenhouse-grown plants, but every plant must be artificially agroinfiltrated, and open greenhouse systems are less controlled. Here, we propose to propagate agrobacteria-free plants with high-efficient long-term self-replicated transient gene expression in a well-controlled closed in vitro system. Nicotiana benthamiana plant tissue culture in vitro, with transient expression of recombinant GFP, was obtained through shoot induction from leaf explants infected by a PVX-based vector. The transient expression occurs in new tissues and regenerants due to the natural systemic distribution of viral RNA carrying the target gene. Gene silencing was delayed in plants grown in vitro, and GFP was detected in plants for five to six months. Agrobacteria-free, GFP-expressing plants can be micropropagated in vitro (avoiding an agroinfiltration step), "rejuvenated" through regeneration (maintaining culture for years), or transferred in soil. The mean GFP in the regenerants was 18% of the total soluble proteins (TSP) (0.52 mg/g of fresh leaf weight (FW). The highest value reached 47% TSP (2 mg/g FW). This study proposes a new method for recombinant protein production combining the advantages of transient expression technology and closed cultural systems.
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Park CH, Song EG, Ryu KH. A multiplex PCR assay for the simultaneous detection of five potexviruses infecting cactus plants using dual-priming oligonucleotides (DPOs) primers. J Virol Methods 2021; 298:114280. [PMID: 34592336 DOI: 10.1016/j.jviromet.2021.114280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/19/2021] [Accepted: 09/03/2021] [Indexed: 11/15/2022]
Abstract
Five potexviruses, namely, cactus virus X (CVX), opuntia virus X, pitaya virus X (PiVX), schlumbergera virus X (SchVX) and zygocactus virus X (ZyVX), have been reported in cactus plants. In this report, a multiplex RT-PCR assay, based on specific dual-priming oligonucleotide (DPO) primers, was developed to detect these five viruses simultaneously in field samples. Using 18 field plants comprising 16 cactus species, these viruses were detected among nine of the 18 plants, including the simultaneous detection of CVX, PiVX, SchVX and ZyVX co-infecting an Aporocactus flagelliformis and a Notocactus leninghausii f. cristatus plant. The multiplex PCR assay was thus applied successfully in the field plants and it would be useful in the diagnosis of viral infections in cactus plants.
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Affiliation(s)
- Chung Hwa Park
- Plant Virus GenBank, Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women's University, Republic of Korea
| | - Eun Gyeong Song
- Plant Virus GenBank, Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women's University, Republic of Korea
| | - Ki Hyun Ryu
- Plant Virus GenBank, Department of Horticulture, Biotechnology and Landscape Architecture, Seoul Women's University, Republic of Korea.
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Mei Y, Beernink BM, Ellison EE, Konečná E, Neelakandan AK, Voytas DF, Whitham SA. Protein expression and gene editing in monocots using foxtail mosaic virus vectors. PLANT DIRECT 2019; 3:e00181. [PMID: 31768497 PMCID: PMC6874699 DOI: 10.1002/pld3.181] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/08/2019] [Accepted: 10/24/2019] [Indexed: 05/03/2023]
Abstract
Plant viruses can be engineered to carry sequences that direct silencing of target host genes, expression of heterologous proteins, or editing of host genes. A set of foxtail mosaic virus (FoMV) vectors was developed that can be used for transient gene expression and single guide RNA delivery for Cas9-mediated gene editing in maize, Setaria viridis, and Nicotiana benthamiana. This was accomplished by duplicating the FoMV capsid protein subgenomic promoter, abolishing the unnecessary open reading frame 5A, and inserting a cloning site containing unique restriction endonuclease cleavage sites immediately after the duplicated promoter. The modified FoMV vectors transiently expressed green fluorescent protein (GFP) and bialaphos resistance (BAR) protein in leaves of systemically infected maize seedlings. GFP was detected in epidermal and mesophyll cells by epifluorescence microscopy, and expression was confirmed by Western blot analyses. Plants infected with FoMV carrying the bar gene were temporarily protected from a glufosinate herbicide, and expression was confirmed using a rapid antibody-based BAR strip test. Expression of these proteins was stabilized by nucleotide substitutions in the sequence of the duplicated promoter region. Single guide RNAs expressed from the duplicated promoter mediated edits in the N. benthamiana Phytoene desaturase gene, the S. viridis Carbonic anhydrase 2 gene, and the maize HKT1 gene encoding a potassium transporter. The efficiency of editing was enhanced in the presence of synergistic viruses and a viral silencing suppressor. This work expands the utility of FoMV for virus-induced gene silencing (VIGS), virus-mediated overexpression (VOX), and virus-enabled gene editing (VEdGE) in monocots.
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Affiliation(s)
- Yu Mei
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Bliss M. Beernink
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Evan E. Ellison
- Department of Genetics, Cell Biology and DevelopmentCenter for Genome EngineeringCenter for Precision Plant GenomicsUniversity of MinnesotaSt. PaulMNUSA
| | - Eva Konečná
- Department of Genetics, Cell Biology and DevelopmentCenter for Genome EngineeringCenter for Precision Plant GenomicsUniversity of MinnesotaSt. PaulMNUSA
| | | | - Daniel F. Voytas
- Department of Genetics, Cell Biology and DevelopmentCenter for Genome EngineeringCenter for Precision Plant GenomicsUniversity of MinnesotaSt. PaulMNUSA
| | - Steven A. Whitham
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
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Jiang MC, Hu CC, Lin NS, Hsu YH. Production of Human IFNγ Protein in Nicotiana benthamiana Plant through an Enhanced Expression System Based on Bamboo mosaic Virus. Viruses 2019; 11:E509. [PMID: 31163694 PMCID: PMC6630494 DOI: 10.3390/v11060509] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 05/30/2019] [Accepted: 06/01/2019] [Indexed: 02/02/2023] Open
Abstract
Plant-based systems are safe alternatives to the current platforms for the production of biologically active therapeutic proteins. However, plant-based expression systems face certain major challenges, including the relatively low productivity and the generation of target proteins in biologically active forms. The use of plant virus-based expression systems has been shown to enhance yields, but further improvement is still required to lower the production cost. In this study, various strategies were employed to increase the yields of an important therapeutic protein, human interferon gamma (IFNγ), in Nicotiana benthamiana through modifications of expression vectors based on potexviruses. Among these, the vector based on a coat protein (CP)-deficient Bamboo mosaic virus (BaMV), pKB△CHis, was shown to exhibit the highest expression level for the unmodified IFNγ. Truncation of the N-terminal signal peptide of IFN (designated mIFNγ) resulted in a nearly seven-fold increase in yield. Co-expression of a silencing suppressor protein by replacing the coding sequence of BaMV movement protein with that of P19 led to a 40% increase in mIFNγ accumulation. The fusion of endoplasmic reticulum (ER) retention signal with mIFNγ significantly enhanced the accumulation ratio of biologically active dimeric mIFNγ to 87% relative to the non-active monomeric form. The construct pKB19mIFNγER, employing the combination of all the above enhancement strategies, gave the highest level of protein accumulation, up to 119 ± 0.8 μg/g fresh weight, accounting for 2.5% of total soluble protein (TSP) content. These findings advocate the application of the modified BaMV-based vector as a platform for high-level expression of therapeutic protein in N. benthamiana.
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Affiliation(s)
- Min-Chao Jiang
- Ph.D Program in Microbial Genomic, National Chung Hsing University and Academia Sinica, Taichung 40227, Taiwan.
| | - Chung-Chi Hu
- Graduate Institute of Biotechnology, Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Na-Sheng Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan.
| | - Yau-Heiu Hsu
- Graduate Institute of Biotechnology, Advanced Plant Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan.
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Ur Rehman A, Li Z, Yang Z, Waqas M, Wang G, Xu W, Li F, Hong N. The Coat Protein of Citrus Yellow Vein Clearing Virus Interacts with Viral Movement Proteins and Serves as an RNA Silencing Suppressor. Viruses 2019; 11:E329. [PMID: 30959816 PMCID: PMC6520955 DOI: 10.3390/v11040329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/27/2019] [Accepted: 04/04/2019] [Indexed: 01/29/2023] Open
Abstract
Citrus yellow vein clearing virus is a newly accepted member of the genus Mandarivirus in the family Alphaflexiviridae. The triple gene block proteins (TGBp1, TGBp2 and TGBp3) encoded by plant viruses in this family function on facilitating virus movement. However, the protein function of citrus yellow vein clearing virus (CYVCV) have never been explored. Here, we showed in both yeast two-hybrid (Y2H) and bimolecular fluorescence (BiFC) assays that the coat protein (CP), TGBp1 and TGBp2 of CYVCV are self-interacting. Its CP also interacts with all three TGB proteins, and TGBp1 and TGBp2 interact with each other but not with TGBp3. Furthermore, the viral CP colocalizes with TGBp1 and TGBp3 at the plasmodesmata (PD) of epidermal cells of Nicotiana benthamiana leaves, and TGBp1 can translocate TGBp2 from granular-like structures embedded within ER networks to the PD. The results suggest that these proteins could coexist at the PD of epidermal cells of N. benthamiana. Using Agrobacterium infiltration-mediated RNA silencing assays, we show that CYVCV CP is a strong RNA silencing suppressor (RSS) triggered by positive-sense green fluorescent protein (GFP) RNA. The presented results provide insights for further revealing the mechanism of the viral movement and suppression of RNA silencing.
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Affiliation(s)
- Atta Ur Rehman
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- Key Laboratory of Horticultural Crop (Fruit Trees) Biology and Germplasm Creation of the Ministry of Agriculture, Wuhan 430070, China.
- Plant Pathology Section, Central Cotton Research Institute, Sakrand, Sindh 67210, Pakistan.
| | - Zhuoran Li
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
| | - Zuokun Yang
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- Key Laboratory of Horticultural Crop (Fruit Trees) Biology and Germplasm Creation of the Ministry of Agriculture, Wuhan 430070, China.
| | - Muhammad Waqas
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
| | - Guoping Wang
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- Key Laboratory of Horticultural Crop (Fruit Trees) Biology and Germplasm Creation of the Ministry of Agriculture, Wuhan 430070, China.
| | - Wenxing Xu
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- Key Laboratory of Horticultural Crop (Fruit Trees) Biology and Germplasm Creation of the Ministry of Agriculture, Wuhan 430070, China.
| | - Feng Li
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
| | - Ni Hong
- Key Lab of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
- Key Laboratory of Horticultural Crop (Fruit Trees) Biology and Germplasm Creation of the Ministry of Agriculture, Wuhan 430070, China.
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Chen I, Chen H, Huang Y, Huang H, Shenkwen L, Hsu Y, Tsai C. A thioredoxin NbTRXh2 from Nicotiana benthamiana negatively regulates the movement of Bamboo mosaic virus. MOLECULAR PLANT PATHOLOGY 2018; 19:405-417. [PMID: 28052479 PMCID: PMC6637981 DOI: 10.1111/mpp.12532] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/25/2016] [Accepted: 12/29/2016] [Indexed: 05/05/2023]
Abstract
An up-regulated gene derived from Bamboo mosaic virus (BaMV)-infected Nicotiana benthamiana plants was cloned and characterized in this study. BaMV is a single-stranded, positive-sense RNA virus. This gene product, designated as NbTRXh2, was matched with sequences of thioredoxin h proteins, a group of small proteins with a conserved active-site motif WCXPC conferring disulfide reductase activity. To examine how NbTRXh2 is involved in the infection cycle of BaMV, we used the virus-induced gene silencing technique to knock down NbTRXh2 expression in N. benthamiana and inoculated the plants with BaMV. We observed that, compared with control plants, BaMV coat protein accumulation increased in knockdown plants at 5 days post-inoculation (dpi). Furthermore, BaMV coat protein accumulation did not differ significantly between NbTRXh2-knockdown and control protoplasts at 24 hpi. The BaMV infection foci in NbTRXh2-knockdown plants were larger than those in control plants. In addition, BaMV coat protein accumulation decreased when NbTRXh2 was transiently expressed in plants. These results suggest that NbTRXh2 plays a role in restricting BaMV accumulation. Moreover, confocal microscopy results showed that NbTRXh2-OFP (NbTRXh2 fused with orange fluorescent protein) localized at the plasma membrane, similar to AtTRXh9, a homologue in Arabidopsis. The expression of the mutant that did not target the substrates failed to reduce BaMV accumulation. Co-immunoprecipitation experiments revealed that the viral movement protein TGBp2 could be the target of NbTRXh2. Overall, the functional role of NbTRXh2 in reducing the disulfide bonds of targeting factors, encoded either by the host or virus (TGBp2), is crucial in restricting BaMV movement.
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Affiliation(s)
- I‐Hsuan Chen
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Hui‐Ting Chen
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Ying‐Ping Huang
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Hui‐Chen Huang
- Biotechnology CenterNational Chung Hsing UniversityTaichung402Taiwan
| | - Lin‐Ling Shenkwen
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Yau‐Heiu Hsu
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
| | - Ching‐Hsiu Tsai
- Graduate Institute of BiotechnologyNational Chung Hsing UniversityTaichung402Taiwan
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8
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Fujita N, Komatsu K, Ayukawa Y, Matsuo Y, Hashimoto M, Netsu O, Teraoka T, Yamaji Y, Namba S, Arie T. N-terminal region of cysteine-rich protein (CRP) in carlaviruses is involved in the determination of symptom types. MOLECULAR PLANT PATHOLOGY 2018; 19:180-190. [PMID: 27868376 PMCID: PMC6638135 DOI: 10.1111/mpp.12513] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 10/19/2016] [Accepted: 11/14/2016] [Indexed: 05/04/2023]
Abstract
Plant viruses in the genus Carlavirus include more than 65 members. Plants infected with carlaviruses exhibit various symptoms, including leaf malformation and plant stunting. Cysteine-rich protein (CRP) encoded by carlaviruses has been reported to be a pathogenicity determinant. Carlavirus CRPs contain two motifs in their central part: a nuclear localization signal (NLS) and a zinc finger motif (ZF). In addition to these two conserved motifs, carlavirus CRPs possess highly divergent, N-terminal, 34 amino acid residues with unknown function. In this study, to analyse the role of these distinct domains, we tested six carlavirus CRPs for their RNA silencing suppressor activity, ability to enhance the pathogenicity of a heterologous virus and effects on virus accumulation levels. Although all six tested carlavirus CRPs showed RNA silencing suppressor activity at similar levels, symptoms induced by the Potato virus X (PVX) heterogeneous system exhibited two different patterns: leaf malformation and whole-plant stunting. The expression of each carlavirus CRP enhanced PVX accumulation levels, which were not correlated with symptom patterns. PVX-expressing CRP with mutations in either NLS or ZF did not induce symptoms, suggesting that both motifs play critical roles in symptom expression. Further analysis using chimeric CRPs, in which the N-terminal region was replaced with the corresponding region of another CRP, suggested that the N-terminal region of carlavirus CRPs determined the exhibited symptom types. The up-regulation of a plant gene upp-L, which has been reported in a previous study, was also observed in this study; however, the expression level was not responsible for symptom types.
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Affiliation(s)
- Naoko Fujita
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of Tokyo113‐8657 TokyoJapan
| | - Ken Komatsu
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
| | - Yu Ayukawa
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
- United Graduate School of Agricultural ScienceTokyo University of Agriculture and TechnologyFuchu183‐8509Japan
| | - Yuki Matsuo
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
| | - Masayoshi Hashimoto
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of Tokyo113‐8657 TokyoJapan
| | - Osamu Netsu
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of Tokyo113‐8657 TokyoJapan
| | - Tohru Teraoka
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
| | - Yasuyuki Yamaji
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of Tokyo113‐8657 TokyoJapan
| | - Shigetou Namba
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life SciencesThe University of Tokyo113‐8657 TokyoJapan
| | - Tsutomu Arie
- Laboratory of Plant Pathology, Graduate School of AgricultureTokyo University of Agriculture and Technology (TUAT)183‐8509 FuchuJapan
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Huang YP, Chen IH, Tsai CH. Host Factors in the Infection Cycle of Bamboo mosaic virus. Front Microbiol 2017; 8:437. [PMID: 28360904 PMCID: PMC5350103 DOI: 10.3389/fmicb.2017.00437] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/02/2022] Open
Abstract
To complete the infection cycle efficiently, the virus must hijack the host systems in order to benefit for all the steps and has to face all the defense mechanisms from the host. This review involves a discussion of how these positive and negative factors regulate the viral RNA accumulation identified for the Bamboo mosaic virus (BaMV), a single-stranded RNA virus. The genome of BaMV is approximately 6.4 kb in length, encoding five functional polypeptides. To reveal the host factors involved in the infection cycle of BaMV, a few different approaches were taken to screen the candidates. One of the approaches is isolating the viral replicase-associated proteins by co-immunoprecipitation with the transiently expressed tagged viral replicase in plants. Another approach is using the cDNA-amplified fragment length polymorphism technique to screen the differentially expressed genes derived from N. benthamiana plants after infection. The candidates are examined by knocking down the expression in plants using the Tobacco rattle virus-based virus-induced gene silencing technique following BaMV inoculation. The positive or negative regulators could be described as reducing or enhancing the accumulation of BaMV in plants when the expression levels of these proteins are knocked down. The possible roles of these host factors acting on the accumulation of BaMV will be discussed.
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Affiliation(s)
- Ying-Ping Huang
- Graduate Institute of Biotechnology, National Chung Hsing University Taichung, Taiwan
| | - I-Hsuan Chen
- Graduate Institute of Biotechnology, National Chung Hsing University Taichung, Taiwan
| | - Ching-Hsiu Tsai
- Graduate Institute of Biotechnology, National Chung Hsing University Taichung, Taiwan
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10
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Hajizadeh M, Sokhandan-Bashir N. Population genetic analysis of potato virus X based on the CP gene sequence. Virusdisease 2017; 28:93-101. [PMID: 28466060 PMCID: PMC5377869 DOI: 10.1007/s13337-017-0362-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 01/27/2017] [Indexed: 11/30/2022] Open
Abstract
To investigate the genetic variation and molecular evolution of potato virus X (PVX), 87 coat protein (CP) gene sequences were retrieved from GenBank and analyzed. Of the PVX isolates studied, one recombinant isolate (X3) was detected from South America population of the virus. The other isolates belonged to two lineages, Eurasia and America, with the significant FST value (0.60). Non-synonymous nucleotide diversity to synonymous nucleotide diversity (ω = dN/dS) was less than 1 indicating that the CP gene has been under negative selection or neutral evolution. Further analysis showed that all of the codons in both lineages were under negative selection pressure. No significant genetic differentiation was found between Chinese, Indian, Iranian, Japanese, and the UK populations whereas South America population was distinctly differentiated from other populations. Different evolutionary constraints found for the two lineages suggest that possible mutations and genetic drift were important evolutionary forces driving the genetic diversification of PVX population.
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Affiliation(s)
- Mohammad Hajizadeh
- Plant Protection Department, College of Agriculture, University of Kurdistan, Sanandaj, Iran
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11
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Liou MR, Hu CC, Chou YL, Chang BY, Lin NS, Hsu YH. Viral elements and host cellular proteins in intercellular movement of Bamboo mosaic virus. Curr Opin Virol 2015; 12:99-108. [PMID: 25951346 DOI: 10.1016/j.coviro.2015.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 04/15/2015] [Accepted: 04/17/2015] [Indexed: 12/23/2022]
Abstract
As a member of the genus Potexvirus, Bamboo mosaic virus (BaMV) also belongs to the plant viruses that encode triple gene block proteins (TGBps) for intercellular movement within the host plants. Recent studies of the movement mechanisms of BaMV have revealed similarities and differences between BaMV and other potexviruses. This review focuses on the general aspects of viral and host elements involved in BaMV movement, the interactions among these elements, and the possible pathways for intra- and intercellular trafficking of BaMV. Major features of BaMV trafficking that have not been demonstrated in other potexviruses include: (i) the involvement of replicase, (ii) fine regulation by coat protein phosphorylation, (iii) the key roles played by TGBp3, (iv) the use of virions as the major transported form, and (v) the involvement of specific host factors, such as Ser/Thr kinase-like protein of Nicotiana benthamiana. We also highlight areas for future study that will provide a more comprehensive understanding of the detailed interactions among viral movement proteins and host factors, as well as the regulatory mechanisms of virus movement. Finally, a model based on the current knowledge is proposed to depict the diverse abilities of BaMV to utilize a wide range of mechanisms for efficient intercellular movement.
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Affiliation(s)
- Ming-Ru Liou
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Chung-Chi Hu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan
| | - Yuan-Lin Chou
- Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan
| | - Ban-Yang Chang
- Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan
| | - Na-Sheng Lin
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yau-Heiu Hsu
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan.
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Hwang J, Lee S, Lee JH, Kang WH, Kang JH, Kang MY, Oh CS, Kang BC. Plant Translation Elongation Factor 1Bβ Facilitates Potato Virus X (PVX) Infection and Interacts with PVX Triple Gene Block Protein 1. PLoS One 2015; 10:e0128014. [PMID: 26020533 PMCID: PMC4447259 DOI: 10.1371/journal.pone.0128014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 04/21/2015] [Indexed: 11/19/2022] Open
Abstract
The eukaryotic translation elongation factor 1 (eEF1) has two components: the G-protein eEF1A and the nucleotide exchange factor eEF1B. In plants, eEF1B is itself composed of a structural protein (eEF1Bγ) and two nucleotide exchange subunits (eEF1Bα and eEF1Bβ). To test the effects of elongation factors on virus infection, we isolated eEF1A and eEF1B genes from pepper (Capsicum annuum) and suppressed their homologs in Nicotiana benthamiana using virus-induced gene silencing (VIGS). The accumulation of a green fluorescent protein (GFP)-tagged Potato virus X (PVX) was significantly reduced in the eEF1Bβ- or eEF1Bɣ-silenced plants as well as in eEF1A-silenced plants. Yeast two-hybrid and co-immunoprecipitation analyses revealed that eEF1Bα and eEF1Bβ interacted with eEF1A and that eEF1A and eEF1Bβ interacted with triple gene block protein 1 (TGBp1) of PVX. These results suggest that both eEF1A and eEF1Bβ play essential roles in the multiplication of PVX by physically interacting with TGBp1. Furthermore, using eEF1Bβ deletion constructs, we found that both N- (1-64 amino acids) and C-terminal (150-195 amino acids) domains of eEF1Bβ are important for the interaction with PVX TGBp1 and that the C-terminal domain of eEF1Bβ is involved in the interaction with eEF1A. These results suggest that eEF1Bβ could be a potential target for engineering virus-resistant plants.
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Affiliation(s)
- JeeNa Hwang
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
- Korea Institute of Science and Technology Information, Seoul, 130–741, Korea
| | - Seonhee Lee
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
| | - Joung-Ho Lee
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
| | - Won-Hee Kang
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
| | - Jin-Ho Kang
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
- Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, 232–916, Korea
| | - Min-Young Kang
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
| | - Chang-Sik Oh
- Department of Horticultural Biotechnology, Kyung Hee University, Yongin, 446–701, Korea
| | - Byoung-Cheorl Kang
- Department of Plant Science, Plant Genomics & Breeding Institute, and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Korea
- Crop Biotechnology Institute/GreenBio Science and Technology, Seoul National University, Pyeongchang, 232–916, Korea
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Geng C, Cong QQ, Li XD, Mou AL, Gao R, Liu JL, Tian YP. DEVELOPMENTALLY REGULATED PLASMA MEMBRANE PROTEIN of Nicotiana benthamiana contributes to potyvirus movement and transports to plasmodesmata via the early secretory pathway and the actomyosin system. PLANT PHYSIOLOGY 2015; 167:394-410. [PMID: 25540331 PMCID: PMC4326756 DOI: 10.1104/pp.114.252734] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/23/2014] [Indexed: 05/09/2023]
Abstract
The intercellular movement of plant viruses requires both viral and host proteins. Previous studies have demonstrated that the frame-shift protein P3N-PIPO (for the protein encoded by the open reading frame [ORF] containing 5'-terminus of P3 and a +2 frame-shift ORF called Pretty Interesting Potyviridae ORF and embedded in the P3) and CYLINDRICAL INCLUSION (CI) proteins were required for potyvirus cell-to-cell movement. Here, we provide genetic evidence showing that a Tobacco vein banding mosaic virus (TVBMV; genus Potyvirus) mutant carrying a truncated PIPO domain of 58 amino acid residues could move between cells and induce systemic infection in Nicotiana benthamiana plants; mutants carrying a PIPO domain of seven, 20, or 43 amino acid residues failed to move between cells and cause systemic infection in this host plant. Interestingly, the movement-defective mutants produced progeny that eliminated the previously introduced stop codons and thus restored their systemic movement ability. We also present evidence showing that a developmentally regulated plasma membrane protein of N. benthamiana (referred to as NbDREPP) interacted with both P3N-PIPO and CI of the movement-competent TVBMV. The knockdown of NbDREPP gene expression in N. benthamiana impeded the cell-to-cell movement of TVBMV. NbDREPP was shown to colocalize with TVBMV P3N-PIPO and CI at plasmodesmata (PD) and traffic to PD via the early secretory pathway and the actomyosin motility system. We also show that myosin XI-2 is specially required for transporting NbDREPP to PD. In conclusion, NbDREPP is a key host protein within the early secretory pathway and the actomyosin motility system that interacts with two movement proteins and influences virus movement.
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Affiliation(s)
- Chao Geng
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Qian-Qian Cong
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Xiang-Dong Li
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - An-Li Mou
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Rui Gao
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Jin-Liang Liu
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
| | - Yan-Ping Tian
- Laboratory of Plant Virology, Department of Plant Pathology, College of Plant Protection (C.G., Q.-Q.C., X.-D.L., A.-L.M., R.G., J.-L.L., Y.-P.T.), and Collaborative Innovation Centre for Annually High Yield and High Efficiency Production of Wheat and Corn (C.G., X.-D.L.), Shandong Agricultural University, Tai'an, Shandong 271018, China; andCollege of Plant Sciences, Jilin University, Changchun 130062, China (J.-L.L.)
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14
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Kumar D, Kumar R, Hyun TK, Kim JY. Cell-to-cell movement of viruses via plasmodesmata. JOURNAL OF PLANT RESEARCH 2015; 128:37-47. [PMID: 25527904 DOI: 10.1007/s10265-014-0683-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/14/2014] [Indexed: 05/03/2023]
Abstract
Plant viruses utilize plasmodesmata (PD), unique membrane-lined cytoplasmic nanobridges in plants, to spread infection cell-to-cell and long-distance. Such invasion involves a range of regulatory mechanisms to target and modify PD. Exciting discoveries in this field suggest that these mechanisms are executed by the interaction between plant cellular components and viral movement proteins (MPs) or other virus-encoded factors. Striking working analogies exist among endogenous non-cell-autonomous proteins and viral MPs, in which not only do they all use PD to traffic, but also they exploit same regulatory components to exert their functions. Thus, this review discusses on the viral strategies to move via PD and the PD-regulatory mechanisms involved in viral pathogenesis.
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Affiliation(s)
- Dhinesh Kumar
- Division of Applied Life Science (BK21plus), Department of Biochemistry, Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, 27-306, 501 Jinju-Daero, Jinju, 660-701, Korea
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15
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Mathioudakis MM, Rodríguez-Moreno L, Sempere RN, Aranda MA, Livieratos I. Multifaceted capsid proteins: multiple interactions suggest multiple roles for Pepino mosaic virus capsid protein. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1356-69. [PMID: 25162316 DOI: 10.1094/mpmi-07-14-0195-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pepino mosaic virus (PepMV) (family Alphaflexiviridae, genus Potexvirus) is a mechanically transmitted tomato pathogen that, over the last decade, has evolved from emerging to endemic worldwide. Here, two heat-shock cognate (Hsc70) isoforms were identified as part of the coat protein (CP)/Hsc70 complex in vivo, following full-length PepMV and CP agroinoculation. PepMV accumulation was severely reduced in Hsp70 virus-induced gene silenced and in quercetin-treated Nicotiana benthamiana plants. Similarly, in vitro-transcribed as well as virion RNA input levels were reduced in quercetin-treated protoplasts, suggesting an essential role for Hsp70 in PepMV replication. As for Potato virus X, the PepMV CP and triple gene-block protein 1 (TGBp1) self-associate and interact with each other in vitro but, unlike in the prototype, both PepMV proteins represent suppressors of transgene-induced RNA silencing with different modes of action; CP is a more efficient suppressor of RNA silencing, sequesters the silencing signal by preventing its spread to neighboring cells and its systemic movement. Here, we provide evidence for additional roles of the PepMV CP and host-encoded Hsp70 in viral infection, the first as a truly multifunctional protein able to specifically bind to a host chaperone and to counterattack an RNA-based defense mechanism, and the latter as an essential factor for PepMV infection.
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16
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Hung CJ, Huang YW, Liou MR, Lee YC, Lin NS, Meng M, Tsai CH, Hu CC, Hsu YH. Phosphorylation of coat protein by protein kinase CK2 regulates cell-to-cell movement of Bamboo mosaic virus through modulating RNA binding. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1211-25. [PMID: 25025779 DOI: 10.1094/mpmi-04-14-0112-r] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
In this study, we investigated the fine regulation of cell-to-cell movement of Bamboo mosaic virus (BaMV). We report that the coat protein (CP) of BaMV is phosphorylated in planta at position serine 241 (S241), in a process involving Nicotiana benthamiana casein kinase 2α (NbCK2α). BaMV CP and NbCK2α colocalize at the plasmodesmata, suggesting that phosphorylation of BaMV may be involved in its movement. S241 was mutated to examine the effects of temporal and spatial dysregulation of phosphorylation on i) the interactions between CP and viral RNA and ii) the regulation of cell-to-cell movement. Replacement of S241 with alanine did not affect RNA binding affinity but moderately impaired cell-to-cell movement. A negative charge at position 241 reduced the ability of CP to bind RNA and severely interfered with cell-to-cell movement. Deletion of residues 240 to 242 increased the affinity of CP to viral RNA and dramatically impaired cell-to-cell movement. A threonine at position 241 changed the binding preference of CP toward genomic RNA and inhibited cell-to-cell movement. Together, these results reveal a fine regulatory mechanism for the cell-to-cell movement of BaMV, which involves the modulation of RNA binding affinity through appropriate phosphorylation of CP by NbCK2α.
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17
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Koh KW, Lu HC, Chan MT. Virus resistance in orchids. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 228:26-38. [PMID: 25438783 DOI: 10.1016/j.plantsci.2014.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 04/07/2014] [Accepted: 04/17/2014] [Indexed: 06/04/2023]
Abstract
Orchid plants, Phalaenopsis and Dendrobium in particular, are commercially valuable ornamental plants sold worldwide. Unfortunately, orchid plants are highly susceptible to viral infection by Cymbidium mosaic virus (CymMV) and Odotoglossum ringspot virus (ORSV), posing a major threat and serious economic loss to the orchid industry worldwide. A major challenge is to generate an effective method to overcome plant viral infection. With the development of optimized orchid transformation biotechnological techniques and the establishment of concepts of pathogen-derived resistance (PDR), the generation of plants resistant to viral infection has been achieved. The PDR concept involves introducing genes that is(are) derived from the virus into the host plant to induce RNA- or protein-mediated resistance. We here review the fundamental mechanism of the PDR concept, and illustrate its application in protecting against viral infection of orchid plants.
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Affiliation(s)
- Kah Wee Koh
- Academia Sinica Biotechnology Center in Southern Taiwan, Tainan, Taiwan
| | - Hsiang-Chia Lu
- Academia Sinica Biotechnology Center in Southern Taiwan, Tainan, Taiwan
| | - Ming-Tsair Chan
- Academia Sinica Biotechnology Center in Southern Taiwan, Tainan, Taiwan; Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan.
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18
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Massumi H, Poormohammadi S, Pishyar S, Maddahian M, Heydarnejad J, Hosseini-Pour A, van Bysterveldt K, Varsani A. Molecular characterization and field survey of Iranian potato virus X isolates. Virusdisease 2014; 25:338-44. [PMID: 25674601 PMCID: PMC4188192 DOI: 10.1007/s13337-014-0222-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022] Open
Abstract
Six hundred and one symptomatic potato samples were collected from nine provinces in Iran. Screening by double-antibody sandwich enzyme linked immunosorbent assay using a potato virus X (PVX) together with a few potyviruses polyclonal antibodies, produced positive reactions in 4.3 % of samples against PVX. Based on symptoms on different test plant, the isolates were divided into two groups: the first groups causing blistering and malformation of leaves and the second showed mild mosaic and vein clearing in Nicotiana glutinosa. The almost complete nucleotide sequence of two isolates as a representative of severe and a mild isolates were determined. Genomes of two PVX Iranian isolates are identical to that of the most PVX isolates comprise 6435 nucleotides in length excluding 101 nucleotide in the 5' end of the genome and shares 94.8-96.7 % identities with European and Asian, and 77-96.1 % with American isolates. Furthermore, the 3'-terminal sequences, including the coat protein coding region of other 13 Iranian isolates were determined and compared with the GenBank sequences. Phylogenetic analysis of the cp gene of 13 Iranian isolates together all those available in public databases indicated that the 13 Iranian isolates all belong to low diversity clade I.
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Affiliation(s)
- Hossain Massumi
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Soodabe Poormohammadi
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Shabnam Pishyar
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mohammad Maddahian
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Jahangir Heydarnejad
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Akbar Hosseini-Pour
- />Department of Plant Protection, College of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Katherine van Bysterveldt
- />School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140 New Zealand
| | - Arvind Varsani
- />School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140 New Zealand
- />Biomolecular Interaction Centre, University of Canterbury, Private Bag 4800, Christchurch, 8140 New Zealand
- />Electron Microscope Unit, Division of Medical Biochemistry, Department of Clinical Laboratory Sciences, University of Cape Town, Cape Town, 7925 South Africa
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19
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Alam CM, Singh AK, Sharfuddin C, Ali S. Incidence, complexity and diversity of simple sequence repeats across potexvirus genomes. Gene 2014; 537:189-96. [DOI: 10.1016/j.gene.2014.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/15/2013] [Accepted: 01/04/2014] [Indexed: 01/18/2023]
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20
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Park MR, Jeong RD, Kim KH. Understanding the intracellular trafficking and intercellular transport of potexviruses in their host plants. FRONTIERS IN PLANT SCIENCE 2014; 5:60. [PMID: 24672528 PMCID: PMC3957223 DOI: 10.3389/fpls.2014.00060] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/06/2014] [Indexed: 05/22/2023]
Abstract
The movement of potexviruses through the cytoplasm to plasmodesmata (PD) and through PD to adjacent cells depends on the viral and host cellular proteins. Potexviruses encode three movement proteins [referred to as the triple gene block (TGB1-3)]. TGB1 protein moves cell-to-cell through PD and requires TGB2 and TGB3, which are endoplasmic reticulum (ER)-located proteins. TGB3 protein directs the movement of the ER-derived vesicles induced by TGB2 protein from the perinuclear ER to the cortical ER. TGB2 protein physically interacts with TGB3 protein in a membrane-associated form and also interacts with either coat protein (CP) or TGB1 protein at the ER network. Recent studies indicate that potexvirus movement involves the interaction between TGB proteins and CP with host proteins including membrane rafts. A group of host cellular membrane raft proteins, remorins, can serve as a counteracting membrane platform for viral ribonucleoprotein (RNP) docking and can thereby inhibit viral movement. The CP, which is a component of the RNP movement complex, is also critical for viral cell-to-cell movement through the PD. Interactions between TGB1 protein and/or the CP subunit with the 5'-terminus of genomic RNA [viral RNA (vRNA)] form RNP movement complexes and direct the movement of vRNAs through the PD. Recent studies show that tobacco proteins such as NbMPB2C or NbDnaJ-like proteins interact with the stem-loop 1 RNA located at the 5'-terminus of Potato virus X vRNA and regulate intracellular as well as intercellular movement. Although several host proteins that interact with vRNAs or viral proteins and that are crucial for vRNA transport have been screened and characterized, additional host proteins and details of viral movement remain to be characterized. In this review, we describe recent progress in understanding potexvirus movement within and between cells and how such movement is affected by interactions between vRNA/proteins and host proteins.
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Affiliation(s)
- Mi-Ri Park
- Department of Agricultural Biotechnology, Seoul National UniversitySeoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea
- Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
| | - Rae-Dong Jeong
- Advanced Radiation Technology Institute, Korea Atomic Energy Research InstituteJeongeup, South Korea
| | - Kook-Hyung Kim
- Department of Agricultural Biotechnology, Seoul National UniversitySeoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National UniversitySeoul, South Korea
- Research Institute for Agriculture and Life Sciences, Seoul National UniversitySeoul, South Korea
- *Correspondence: Kook-Hyung Kim, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, South Korea e-mail:
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21
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Carmo LST, Resende RO, Silva LP, Ribeiro SG, Mehta A. Identification of host proteins modulated by the virulence factor AC2 of Tomato chlorotic mottle virus in Nicotiana benthamiana. Proteomics 2013; 13:1947-60. [PMID: 23533094 DOI: 10.1002/pmic.201200547] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/08/2013] [Accepted: 02/25/2013] [Indexed: 11/09/2022]
Abstract
Tomato, one of the most important crops cultivated worldwide, has been severely affected by begomoviruses such as the Tomato chlorotic mottle virus (ToCMoV). Virulence factor AC2 is considered crucial for a successful virus-plant interaction and is known to act as a transcriptional activator and in some begomoviruses to function as an RNA silencing suppressor factor. However, the exact functions of the AC2 protein of the begomovirus ToCMoV are not yet established. The aim of the present study was to identify differentially expressed proteins of the model plant Nicotiana benthamiana in response to the expression of the AC2 gene, isolated from ToCMoV. N. benthamiana plants were inoculated with Agrobacterium tumefaciens containing the viral vector Potato virus X (PVX) and with the PVX-AC2 construction. 2DE was performed and proteins were identified by MS. The results showed that the expression of ToCMoV AC2 alters the levels of several host proteins, which are important for normal plant development, causing an imbalance in cellular homeostasis. This study highlights the effect of AC2 in the modulation of plant defense processes by increasing the expression of several oxidative stress-related and pathogenesis-related proteins, as well as its role in modulating the proteome of the photosynthesis and energy production systems.
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22
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Nazim Uddin M, Kim JY. Intercellular and systemic spread of RNA and RNAi in plants. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:279-93. [PMID: 23536229 DOI: 10.1002/wrna.1160] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Plants possess dynamic networks of intercellular communication that are crucial for plant development and physiology. In plants, intercellular communication involves a combination of ligand-receptor-based apoplasmic signaling, and plasmodesmata and phloem-mediated symplasmic signaling. The intercellular trafficking of macromolecules, including RNAs and proteins, has emerged as a novel mechanism of intercellular communication in plants. Various forms of regulatory RNAs move over distinct cellular boundaries through plasmodesmata and phloem. This plant-specific, non-cell-autonomous RNA trafficking network is also involved in development, nutrient homeostasis, gene silencing, pathogen defense, and many other physiological processes. However, the mechanism underlying macromolecular trafficking in plants remains poorly understood. Current progress made in RNA trafficking research and its biological relevance to plant development will be summarized. Diverse plant regulatory mechanisms of cell-to-cell and systemic long-distance transport of RNAs, including mRNAs, viral RNAs, and small RNAs, will also be discussed.
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Affiliation(s)
- Mohammad Nazim Uddin
- Division of Applied Life Science (BK21-WCU Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, South Korea
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23
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Jang C, Seo EY, Nam J, Bae H, Gim YG, Kim HG, Cho IS, Lee ZW, Bauchan GR, Hammond J, Lim HS. Insights into Alternanthera mosaic virus TGB3 Functions: Interactions with Nicotiana benthamiana PsbO Correlate with Chloroplast Vesiculation and Veinal Necrosis Caused by TGB3 Over-Expression. FRONTIERS IN PLANT SCIENCE 2013; 4:5. [PMID: 23386854 PMCID: PMC3560364 DOI: 10.3389/fpls.2013.00005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 01/08/2013] [Indexed: 05/18/2023]
Abstract
Alternanthera mosaic virus (AltMV) triple gene block 3 (TGB3) protein is involved in viral movement. AltMV TGB3 subcellular localization was previously shown to be distinct from that of Potato virus X (PVX) TGB3, and a chloroplast binding domain identified; veinal necrosis and chloroplast vesiculation were observed in Nicotiana benthamiana when AltMV TGB3 was over-expressed from PVX. Plants with over-expressed TGB3 showed more lethal damage under dark conditions than under light. Yeast-two-hybrid analysis and bimolecular fluorescence complementation (BiFC) reveal that Arabidopsis thaliana PsbO1 has strong interactions with TGB3; N. benthamiana PsbO (NbPsbO) also showed obvious interaction signals with TGB3 through BiFC. These results demonstrate an important role for TGB3 in virus cell-to-cell movement and virus-host plant interactions. The Photosystem II oxygen-evolving complex protein PsbO interaction with TGB3 is presumed to have a crucial role in symptom development and lethal damage under dark conditions. In order to further examine interactions between AtPsbO1, NbPsbO, and TGB3, and to identify the binding domain(s) in TGB3 protein, BiFC assays were performed between AtPsbO1 or NbPsbO and various mutants of TGB3. Interactions with C-terminally deleted TGB3 were significantly weaker than those with wild-type TGB3, and both N-terminally deleted TGB3 and a TGB3 mutant previously shown to lose chloroplast interactions failed to interact detectably with PsbO in BiFC. To gain additional information about TGB3 interactions in AltMV-susceptible plants, we cloned 12 natural AltMV TGB3 sequence variants into a PVX expression vector to examine differences in symptom development in N. benthamiana. Symptom differences were observed on PVX over-expression, with all AltMV TGB3 variants showing more severe symptoms than the WT PVX control, but without obvious correlation to sequence differences.
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Affiliation(s)
- Chanyong Jang
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
| | - Eun-Young Seo
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
| | - Jiryun Nam
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
| | - Hanhong Bae
- School of Biotechnology, Yeungnam UniversityGyeongsan, South Korea
| | - Yeong Guk Gim
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
| | - Hong Gi Kim
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
| | - In Sook Cho
- National Institute of Horticultural and Herbal Science, Rural Development AdministrationSuwon, South Korea
| | - Zee-Won Lee
- Division of Life Science, Korea Basic Science InstituteDaejeon, South Korea
| | - Gary R. Bauchan
- Electron and Confocal Microscopy Unit, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of AgricultureBeltsville, MD, USA
| | - John Hammond
- Floral and Nursery Plants Research Unit, US National Arboretum, Agricultural Research Service, United States Department of AgricultureBeltsville, MD, USA
- *Correspondence: John Hammond, Floral and Nursery Plants Research Unit, US National Arboretum, United States Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, B-010A, Beltsville, MD 20705, USA. e-mail: ; Hyoun-Sub Lim, Department of Applied Biology, Chungnam National University, 79 Daehangno, Yuseong-gu, Daejeon 305-764, South Korea. e-mail:
| | - Hyoun-Sub Lim
- Department of Applied Biology, Chungnam National UniversityDaejeon, South Korea
- *Correspondence: John Hammond, Floral and Nursery Plants Research Unit, US National Arboretum, United States Department of Agriculture, Agricultural Research Service, 10300 Baltimore Avenue, B-010A, Beltsville, MD 20705, USA. e-mail: ; Hyoun-Sub Lim, Department of Applied Biology, Chungnam National University, 79 Daehangno, Yuseong-gu, Daejeon 305-764, South Korea. e-mail:
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Cowan GH, Roberts AG, Chapman SN, Ziegler A, Savenkov EI, Torrance L. The potato mop-top virus TGB2 protein and viral RNA associate with chloroplasts and viral infection induces inclusions in the plastids. FRONTIERS IN PLANT SCIENCE 2012; 3:290. [PMID: 23269927 PMCID: PMC3529358 DOI: 10.3389/fpls.2012.00290] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/05/2012] [Indexed: 05/27/2023]
Abstract
The potato mop-top virus (PMTV) triple gene block 2 (TGB2) movement proteins fused to monomeric red fluorescent protein (mRFP-TGB2) was expressed under the control of the PMTV subgenomic promoter from a PMTV vector. The subcellular localizations and interactions of mRFP-TGB2 were investigated using confocal imaging [confocal laser-scanning microscope, (CLSM)] and biochemical analysis. The results revealed associations with membranes of the endoplasmic reticulum (ER), mobile granules, small round structures (1-2 μm in diameter), and chloroplasts. Expression of mRFP-TGB2 in epidermal cells enabled cell-to-cell movement of a TGB2 defective PMTV reporter clone, indicating that the mRFP-TGB2 fusion protein was functional and required for cell-to-cell movement. Protein-lipid interaction assays revealed an association between TGB2 and lipids present in chloroplasts, consistent with microscopical observations where the plastid envelope was labeled later in infection. To further investigate the association of PMTV infection with chloroplasts, ultrastructural studies of thin sections of PMTV-infected potato and Nicotiana benthamiana leaves by electron microscopy revealed abnormal chloroplasts with cytoplasmic inclusions and terminal projections. Viral coat protein (CP), genomic RNA and fluorescently-labeled TGB2 were detected in plastid preparations isolated from the infected leaves, and viral RNA was localized to chloroplasts in infected tissues. The results reveal a novel association of TGB2 and vRNA with chloroplasts, and suggest viral replication is associated with chloroplast membranes, and that TGB2 plays a novel role in targeting the virus to chloroplasts.
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Affiliation(s)
| | | | | | - Angelika Ziegler
- Federal Research Centre for Cultivated Plants, Julius Kühn Institute, Institute for Epidemiology and Pathogen DiagnosticsQuedlinburg, Germany
| | - Eugene I. Savenkov
- Department of Plant Biology and Forest Genetics, Swedish University of Agricultural SciencesUppsala, Sweden
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Gómez P, Sempere R, Aranda MA. Pepino mosaic virus and Tomato torrado virus: two emerging viruses affecting tomato crops in the Mediterranean basin. Adv Virus Res 2012; 84:505-32. [PMID: 22682177 DOI: 10.1016/b978-0-12-394314-9.00014-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular biology, epidemiology, and evolutionary dynamics of Pepino mosaic virus (PepMV) are much better understood than those of Tomato torrado virus (ToTV). The earliest descriptions of PepMV suggest a recent jump from nontomato species (e.g., pepino; Solanum muricatum) to tomato (Solanum lycopersicum). Its stability in contaminated plant tissues, its transmission through seeds, and the global trade of tomato seeds and fruits may have facilitated the global spread of PepMV. Stability and seed transmission also probably account for the devastating epidemics caused by already-established PepMV strains, although additional contributing factors may include the efficient transmission of PepMV by contact and the often-inconspicuous symptoms in vegetative tomato tissues. The genetic variability of PepMV is likely to have promoted the first phase of emergence (i.e., the species jump) and it continues to play an important role as the virus becomes more pervasive, progressing from regional outbreaks to pandemics. In contrast, the long-term progression of ToTV outbreaks is not yet clear and this may reflect factors such as the limited accumulation of the virus in infected plants, which has been shown to be approximately two orders of magnitude less than PepMV. The efficient dispersion of ToTV may therefore depend on dense populations of its principal vectors, Bemisia tabaci and Trialeurodes vaporariorum, as has been proposed for the necrogenic satellite RNA of Cucumber mosaic virus.
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Affiliation(s)
- Pedro Gómez
- Centro de Edafología y Biología Aplicada del Segura-CEBAS, Consejo Superior de Investigaciones Científicas-CSIC, Campus Universitario de Espinardo, Espinardo, Murcia, Spain
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26
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Rioux G, Majeau N, Leclerc D. Mapping the surface-exposed regions of papaya mosaic virus nanoparticles. FEBS J 2012; 279:2004-11. [PMID: 22524169 DOI: 10.1111/j.1742-4658.2012.08583.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In general, the structure of the papaya mosaic virus (PapMV) and other members of the potexviruses is poorly understood. Production of PapMV coat proteins in a bacterial expression system and their self-assembly in vitro into nanoparticles is a very useful tool to study the structure of this virus. Using recombinant PapMV nanoparticles that are similar in shape and appearance to the plant virus, we evaluated surface-exposed regions by two different methods, immunoblot assay and chemical modification with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide or diethyl-pyrocarbonate followed by mass spectrometry. Three regions were targeted by the two techniques. The N- and C-termini were shown to be surfaced exposed as expected. However, the region 125-136 was revealed for the first time as the major surface-exposed region of the nanoparticles. The presence of linear peptides at the surface was finally confirmed using antibodies directed to those peptides. It is likely that region 125-136 plays a key role in the lifecycle of PapMV and other members of the potexvirus group.
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Affiliation(s)
- Gervais Rioux
- Department of Microbiology Infectiology and Immunology, Infectious Disease Research Centre, Laval University, Quebec City, Canada
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27
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Mathioudakis MM, Veiga R, Ghita M, Tsikou D, Medina V, Canto T, Makris AM, Livieratos IC. Pepino mosaic virus capsid protein interacts with a tomato heat shock protein cognate 70. Virus Res 2012; 163:28-39. [PMID: 21884738 DOI: 10.1016/j.virusres.2011.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 08/12/2011] [Accepted: 08/15/2011] [Indexed: 11/29/2022]
Abstract
Plant viral capsid proteins (CP) can be involved in virus movement, replication and symptom development as a result of their interaction with host factors. The identification of such interactions may thus provide information about viral pathogenesis. In this study, Pepino mosaic virus (PepMV) CP was used as bait to screen a tomato (Solanum lycopersicum) cDNA library for potential interactors in yeast. Of seven independent interacting clones, six were predicted to encode the C-termini of the heat shock cognate 70 (Hsc70) proteins. Three full length tomato Hsc70s (named Hsc70.1, .2, .3) were used to confirm the interaction in the yeast two hybrid assay and bimolecular fluorescent complementation (BiFC) in planta. The PepMV CP-Hsc70 interaction was confirmed only in the case of Hsc70.3 for both assays. In BiFC, the interaction was visualized in the cytoplasm and nucleus of agroinfiltrated Nicotiana benthamiana epidermal cells. During PepMV infection, Hsc70.3 mRNA levels were induced and protein accumulation increased at 48 and 72 h post inoculation. In transmission electron microscopy using immunogold labelling techniques, Hsc70 was detected to co-localize with virions in the phloem of PepMV-infected tomato leaves. These observations, together with the co-purification of Hsc70 with PepMV virions further support the notion of a PepMV CP/Hsc70 interaction during virus infection.
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Affiliation(s)
- Matthaios M Mathioudakis
- Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, Alsylio Agrokepion, GR-73100 Chania, Crete, Greece.
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28
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Senshu H, Yamaji Y, Minato N, Shiraishi T, Maejima K, Hashimoto M, Miura C, Neriya Y, Namba S. A dual strategy for the suppression of host antiviral silencing: two distinct suppressors for viral replication and viral movement encoded by potato virus M. J Virol 2011; 85:10269-78. [PMID: 21752911 PMCID: PMC3196401 DOI: 10.1128/jvi.05273-11] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 06/30/2011] [Indexed: 11/20/2022] Open
Abstract
Viruses encode RNA silencing suppressors to counteract host antiviral silencing. In this study, we analyzed the suppressors encoded by potato virus M (PVM), a member of the genus Carlavirus. In the conventional green fluorescent protein transient coexpression assay, the cysteine-rich protein (CRP) of PVM inhibited both local and systemic silencing, whereas the triple gene block protein 1 (TGBp1) showed suppressor activity only on systemic silencing. Furthermore, to elucidate the roles of these two suppressors during an active viral infection, we performed PVX vector-based assays and viral movement complementation assays. CRP increased the accumulation of viral RNA at the single-cell level and also enhanced viral cell-to-cell movement by inhibiting RNA silencing. However, TGBp1 facilitated viral movement but did not affect viral accumulation in protoplasts. These data suggest that CRP inhibits RNA silencing primarily at the viral replication step, whereas TGBp1 is a suppressor that acts at the viral movement step. Thus, our findings demonstrate a sophisticated viral infection strategy that suppresses host antiviral silencing at two different steps via two mechanistically distinct suppressors. This study is also the first report of the RNA silencing suppressor in the genus Carlavirus.
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Affiliation(s)
- Hiroko Senshu
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yasuyuki Yamaji
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Nami Minato
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takuya Shiraishi
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kensaku Maejima
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masayoshi Hashimoto
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Chihiro Miura
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yutaro Neriya
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shigetou Namba
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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29
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The interaction between bamboo mosaic virus replication protein and coat protein is critical for virus movement in plant hosts. J Virol 2011; 85:12022-31. [PMID: 21917973 DOI: 10.1128/jvi.05595-11] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bamboo mosaic virus (BaMV) is a positive-sense RNA virus belonging to the genus Potexvirus. Open reading frame 1 (ORF1) encodes the viral replication protein that consists of a capping enzyme domain, a helicase-like domain (HLD), and an RNA-dependent RNA polymerase domain from the N to C terminus. ORF5 encodes the viral coat protein (CP) required for genome encapsidation and the virus movement in plants. In this study, application of a yeast-two hybrid assay detected an interaction between the viral HLD and CP. However, the interaction did not affect the NTPase activity of the HLD. To identify the critical amino acids of CP interacting with the HLD, a random mutational library of CP was created using error-prone PCR, and the mutations adversely affecting the interaction were screened by a bacterial two-hybrid system. As a result, the mutations A209G and N210S in CP were found to weaken the interaction. To determine the significance of the interaction, the mutations were introduced into a BaMV infectious clone, and the mutational effects on viral replication, movement, and genome encapsidation were investigated. There was no effect on accumulations of BaMV CP and genomic RNAs within protoplasts; however, the virus cell-to-cell movement in plants was restricted. Sequence alignment revealed that A209 of BaMV CP is conserved in many potexviruses. Mutation of the corresponding residue in Foxtail mosaic virus CP also reduced the viral HLD-CP interaction and restricted the virus movement, suggesting that interaction between CP and a widely conserved HLD in the potexviral replication protein is crucial for viral trafficking through plasmodesmata.
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Liu N, Niu J, Zhao Y. Complete genomic sequence analyses of Apple Stem Pitting Virus isolates from China. Virus Genes 2011; 44:124-30. [PMID: 21909953 DOI: 10.1007/s11262-011-0666-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 08/25/2011] [Indexed: 11/24/2022]
Abstract
The complete genomic sequences of a Chinese ASPV isolates KL1 and KL9 were determined from ten overlapping cDNA clones. The genomes of both isolates were 9265 nucleotides excluding the poly (A) tail and contained five open reading frames (ORFs). The identities between two complete genomes were 92.5% at nt level. Multiple alignment of the amino acid sequences showed that 110 aa variations between two genomic sequences and the variable domains mainly distributed in 5'-terminal of ORF1, ORF3, and ORF5, respectively. Two complete genomic sequences shared 71.4-77.3% identities with other ASPV isolates at nt level. Phylogenetic relationship analysis of the coat protein genes revealed that ASPV isolates had high variables and formed three groups. All ASPV isolates from apples were clustered to group I, whereas pear were clustered to groups II (except NC_003462) and both KL1 and KL9 were clustered to group III. Nucleotide sequences diversity analysis showed that the between-population d(NS)/d(S) ratio 0.092 was similar to these for within-group (0.092-0.095); there was no geographic differentiation between ASPV isolates.
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Affiliation(s)
- Na Liu
- Department of Horticultural, Agricultural College of Shihezi University, 832000 Shihezi, People's Republic of China
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31
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Lu Y, Yan F, Guo W, Zheng H, Lin L, Peng J, Adams MJ, Chen J. Garlic virus X 11-kDa protein granules move within the cytoplasm and traffic a host protein normally found in the nucleolus. MOLECULAR PLANT PATHOLOGY 2011; 12:666-76. [PMID: 21726366 PMCID: PMC6640471 DOI: 10.1111/j.1364-3703.2010.00699.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The subcellular localization of the 11-kDa protein (p11) encoded by ORF3 of Garlic virus X (GarVX; genus Allexivirus, family Alphaflexiviridae) was examined by confocal microscopy. Granules with intense fluorescence were visible on the endoplasmic reticulum when p11 fused with green or red fluorescent protein (GFP or RFP) was expressed in epidermal cells of Nicotiana benthamiana. Moreover, the p11-RFP granules moved in the cytoplasm, along the cell periphery and through the cell membranes to adjacent cells. A 17-kDa protein (p17) of garlic interacting with p11 was identified by yeast two-hybridization and bimolecular fluorescence complementation assay. When p17 fused to GFP was expressed in epidermal cells of N. benthamiana, it localized to the nucleolus. However, in the presence of GarVX p11, the distribution of p17 changed to that of p11, but did not appear to affect the pattern of movement of p11.
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Affiliation(s)
- Yuwen Lu
- State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, MOA and Zhejiang Provincial Key Laboratory of Plant Virology, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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32
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Ueki S, Citovsky V. To gate, or not to gate: regulatory mechanisms for intercellular protein transport and virus movement in plants. MOLECULAR PLANT 2011; 4:782-93. [PMID: 21746703 PMCID: PMC3183397 DOI: 10.1093/mp/ssr060] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Accepted: 06/06/2011] [Indexed: 05/19/2023]
Abstract
Cell-to-cell signal transduction is vital for orchestrating the whole-body physiology of multi-cellular organisms, and many endogenous macromolecules, proteins, and nucleic acids function as such transported signals. In plants, many of these molecules are transported through plasmodesmata (Pd), the cell wall-spanning channel structures that interconnect plant cells. Furthermore, Pd also act as conduits for cell-to-cell movement of most plant viruses that have evolved to pirate these channels to spread the infection. Pd transport is presumed to be highly selective, and only a limited repertoire of molecules is transported through these channels. Recent studies have begun to unravel mechanisms that actively regulate the opening of the Pd channel to allow traffic. This macromolecular transport between cells comprises two consecutive steps: intracellular targeting to Pd and translocation through the channel to the adjacent cell. Here, we review the current knowledge of molecular species that are transported though Pd and the mechanisms that control this traffic. Generally, Pd traffic can occur by passive diffusion through the trans-Pd cytoplasm or through the membrane/lumen of the trans-Pd ER, or by active transport that includes protein-protein interactions. It is this latter mode of Pd transport that is involved in intercellular traffic of most signal molecules and is regulated by distinct and sometimes interdependent mechanisms, which represent the focus of this article.
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Affiliation(s)
- Shoko Ueki
- Institute of Plant Science and Resources, Okayama University, 2-20-1, Chuo, Kurashiki, Okayama 710-0046, Japan.
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33
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He Z, Jiang D, Liu A, Sang L, Li W, Li S. The complete sequence of Cymbidium mosaic virus from Vanilla fragrans in Hainan, China. Virus Genes 2011; 42:440-3. [PMID: 21442302 DOI: 10.1007/s11262-011-0592-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Accepted: 02/25/2011] [Indexed: 10/18/2022]
Abstract
The complete nucleotide sequence of Cymbidium mosaic virus (CymMV) isolated from vanilla in Hainan province, China was determined for the first time. It comprised 6,224 nucleotides; sequence analysis suggested that the isolate we obtained was a member of the genus Potexvirus, and its sequence shared 86.67-96.61% identities with previously reported sequences. Phylogenetic analysis suggested that CymMV from vanilla fragrans was clustered into subgroup A and the isolates in this subgroup displayed little regional difference.
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Affiliation(s)
- Zhen He
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
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34
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Lee WS, Fu SF, Verchot-Lubicz J, Carr JP. Genetic modification of alternative respiration in Nicotiana benthamiana affects basal and salicylic acid-induced resistance to potato virus X. BMC PLANT BIOLOGY 2011; 11:41. [PMID: 21356081 PMCID: PMC3058079 DOI: 10.1186/1471-2229-11-41] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 02/28/2011] [Indexed: 05/06/2023]
Abstract
BACKGROUND Salicylic acid (SA) regulates multiple anti-viral mechanisms, including mechanism(s) that may be negatively regulated by the mitochondrial enzyme, alternative oxidase (AOX), the sole component of the alternative respiratory pathway. However, studies of this mechanism can be confounded by SA-mediated induction of RNA-dependent RNA polymerase 1, a component of the antiviral RNA silencing pathway. We made transgenic Nicotiana benthamiana plants in which alternative respiratory pathway capacity was either increased by constitutive expression of AOX, or decreased by expression of a dominant-negative mutant protein (AOX-E). N. benthamiana was used because it is a natural mutant that does not express a functional RNA-dependent RNA polymerase 1. RESULTS Antimycin A (an alternative respiratory pathway inducer and also an inducer of resistance to viruses) and SA triggered resistance to tobacco mosaic virus (TMV). Resistance to TMV induced by antimycin A, but not by SA, was inhibited in Aox transgenic plants while SA-induced resistance to this virus appeared to be stronger in Aox-E transgenic plants. These effects, which were limited to directly inoculated leaves, were not affected by the presence or absence of a transgene constitutively expressing a functional RNA-dependent RNA polymerase (MtRDR1). Unexpectedly, Aox-transgenic plants infected with potato virus X (PVX) showed markedly increased susceptibility to systemic disease induction and virus accumulation in inoculated and systemically infected leaves. SA-induced resistance to PVX was compromised in Aox-transgenic plants but plants expressing AOX-E exhibited enhanced SA-induced resistance to this virus. CONCLUSIONS We conclude that AOX-regulated mechanisms not only play a role in SA-induced resistance but also make an important contribution to basal resistance against certain viruses such as PVX.
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Affiliation(s)
- Wing-Sham Lee
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Shih-Feng Fu
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Jeanmarie Verchot-Lubicz
- Oklahoma State University, Department of Entomology and Plant Pathology, 127 Noble Research Center, Stillwater, OK 74078, USA
| | - John P Carr
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Hyun TK, Uddin MN, Rim Y, Kim JY. Cell-to-cell trafficking of RNA and RNA silencing through plasmodesmata. PROTOPLASMA 2011; 248:101-16. [PMID: 21042816 DOI: 10.1007/s00709-010-0225-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 10/14/2010] [Indexed: 05/05/2023]
Abstract
Plasmodesmata (PD) are plasma membrane-lined cytoplasmic channels that cross the cell wall and establish symplasmic continuity between neighboring cells in plants. Recently, a wide range of cellular RNAs (including mRNAs and small RNAs (sRNAs)) have been reported to move from cell to cell through PD trafficking pathways. sRNAs are key molecules that function in transcriptional and post-transcriptional RNA silencing, which is a gene expression regulatory mechanism that is conserved among eukaryotes and is important for protection against invading nucleic acids (such as viruses and transposons) and for developmental and physiological regulation. One of the most intriguing aspects of RNA silencing is that it can function either cell autonomously or non-cell autonomously in post-transcriptional RNA silencing pathways. Although the mechanisms underlying cell-to-cell trafficking of RNA and RNA silencing signals are not fully understood, the movement of specific RNAs seems to play a critical role in cell-to-cell and long-distance regulation of gene expression, thereby coordinating growth and developmental processes, gene silencing, and stress responses. In this review, we summarize the current knowledge regarding cell-to-cell trafficking of RNA molecules (including small RNAs), and we discuss potential molecular mechanisms of cell-to-cell trafficking that are mediated by complex networks.
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Affiliation(s)
- Tae Kyung Hyun
- Department of Biochemistry, Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, South Korea
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36
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Niehl A, Heinlein M. Cellular pathways for viral transport through plasmodesmata. PROTOPLASMA 2011; 248:75-99. [PMID: 21125301 DOI: 10.1007/s00709-010-0246-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 11/16/2010] [Indexed: 05/03/2023]
Abstract
Plant viruses use plasmodesmata (PD) to spread infection between cells and systemically. Dependent on viral species, movement through PD can occur in virion or non-virion form, and requires different mechanisms for targeting and modification of the pore. These mechanisms are supported by viral movement proteins and by other virus-encoded factors that interact among themselves and with plant cellular components to facilitate virus movement in a coordinated and regulated fashion.
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Affiliation(s)
- Annette Niehl
- Institut de Biologie Moléculaire des Plantes du CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084, Strasbourg, France
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37
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Liu Z, Kearney CM. An efficient Foxtail mosaic virus vector system with reduced environmental risk. BMC Biotechnol 2010; 10:88. [PMID: 21162736 PMCID: PMC3022558 DOI: 10.1186/1472-6750-10-88] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 12/16/2010] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Plant viral vectors offer high-yield expression of pharmaceutical and commercially important proteins with a minimum of cost and preparation time. The use of Agrobacterium tumefaciens has been introduced to deliver the viral vector as a transgene to each plant cell via a simple, nonsterile infiltration technique called "agroinoculation". With agroinoculation, a full length, systemically moving virus is no longer necessary for excellent protein yield, since the viral transgene is transcribed and replicates in every infiltrated cell. Viral genes may therefore be deleted to decrease the potential for accidental spread and persistence of the viral vector in the environment. RESULTS In this study, both the coat protein (CP) and triple gene block (TGB) genetic segments were eliminated from Foxtail mosaic virus to create the "FECT" vector series, comprising a deletion of 29% of the genome. This viral vector is highly crippled and expresses little or no marker gene within the inoculated leaf. However, when co-agroinoculated with a silencing suppressor (p19 or HcPro), FECT expressed GFP at 40% total soluble protein in the tobacco host, Nicotiana benthamiana. The modified FoMV vector retained the full-length replicase ORF, the TGB1 subgenomic RNA leader sequence and either 0, 22 or 40 bases of TGB1 ORF (in vectors FECT0, FECT22 and FECT40, respectively). As well as N. benthamiana, infection of legumes was demonstrated. Despite many attempts, expression of GFP via syringe agroinoculation of various grass species was very low, reflecting the low Agrobacterium-mediated transformation rate of monocots. CONCLUSIONS The FECT/40 vector expresses foreign genes at a very high level, and yet has a greatly reduced biohazard potential. It can form no virions and can effectively replicate only in a plant with suppressed silencing.
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Affiliation(s)
- Zun Liu
- Department of Biology, Baylor University, One Bear Place #7388, Waco, TX, 76798 USA
- Endocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 USA
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Komarova TV, Baschieri S, Donini M, Marusic C, Benvenuto E, Dorokhov YL. Transient expression systems for plant-derived biopharmaceuticals. Expert Rev Vaccines 2010; 9:859-76. [PMID: 20673010 DOI: 10.1586/erv.10.85] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the molecular farming area, transient expression approaches for pharmaceutical proteins production, mainly recombinant monoclonal antibodies and vaccines, were developed almost two decades ago and, to date, these systems basically depend on Agrobacterium-mediated delivery and virus expression machinery. We survey here the current state-of-the-art of this research field. Several vectors have been designed on the basis of DNA- and RNA-based plant virus genomes and viral vectors are used both as single- and multicomponent expression systems in different combinations depending on the protein of interest. The obvious advantages of these systems are ease of manipulation, speed, low cost and high yield of proteins. In addition, Agrobacterium-mediated expression also allows the production in plants of complex proteins assembled from subunits. Currently, the transient expression methods are preferential over any other transgenic system for the exploitation of large and unrestricted numbers of plants in a contained environment. By designing optimal constructs and related means of delivery into plant cells, the overall technology plan considers scenarios that envisage high yield of bioproducts and ease in monitoring the whole spectrum of upstream production, before entering good manufacturing practice facilities. In this way, plant-derived bioproducts show promise of high competitiveness towards classical eukaryotic cell factory systems.
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Affiliation(s)
- Tatiana V Komarova
- N.I. Vavilov Institute of General Genetics, Russian Academy of Science and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia
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Wright KM, Cowan GH, Lukhovitskaya NI, Tilsner J, Roberts AG, Savenkov EI, Torrance L. The N-terminal domain of PMTV TGB1 movement protein is required for nucleolar localization, microtubule association, and long-distance movement. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1486-97. [PMID: 20923354 DOI: 10.1094/mpmi-05-10-0105] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The triple-gene-block (TGB)1 protein of Potato mop-top virus (PMTV) was fused to fluorescent proteins and expressed in epidermal cells of Nicotiana benthamiana under the control of the 35S promoter. TGB1 fluorescence was observed in the cytoplasm, nucleus, and nucleolus and occasionally associated with microtubules. When expressed from a modified virus (PMTV.YFP-TGB1) which formed local lesions but was not competent for systemic movement, yellow fluorescent protein (YFP)-TGB1 labeled plasmodesmata in cells at the leading edge of the lesion and plasmodesmata, microtubules, nuclei, and nucleoli in cells immediately behind the leading edge. Deletion of 84 amino acids from the N-terminus of unlabeled TGB1 within the PMTV genome abolished movement of viral RNA to noninoculated leaves. When the same deletion was introduced into PMTV.YFP-TGB1, labeling of microtubules and nucleoli was abolished. The N-terminal 84 amino acids of TGB1 were fused to green fluorescent protein (GFP) and expressed in epidermal cells where GFP localized strongly to the nucleolus (not seen with unfused GFP), indicating that these amino acids contain a nucleolar localization signal; the fusion protein did not label microtubules. This is the first report of nucleolar and microtubule association of a TGB movement protein. The results suggest that PMTV TGB1 requires interaction with nuclear components and, possibly, microtubules for long-distance movement of viral RNA.
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Affiliation(s)
- Kathryn M Wright
- Plant Pathology Programme, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK
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Benitez-Alfonso Y, Faulkner C, Ritzenthaler C, Maule AJ. Plasmodesmata: gateways to local and systemic virus infection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:1403-12. [PMID: 20687788 DOI: 10.1094/mpmi-05-10-0116] [Citation(s) in RCA: 119] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
As channels that provide cell-to-cell connectivity, plasmodesmata are central to the local and systemic spread of viruses in plants. This review discusses the current state of knowledge of the structure and function of these channels and the ways in which viruses bring about functional changes that allow macromolecular trafficking to occur. Despite the passing of two decades since the first identification of a viral movement protein that mediates these changes, our understanding of the relevant molecular mechanisms remains in its infancy. However, viral movement proteins provide valuable tools for the modification of plasmodesmata and will continue to assist in the dissection of plasmodesmal properties in relation to their core roles in cell-to-cell communication.
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Lim HS, Vaira AM, Bae H, Bragg JN, Ruzin SE, Bauchan GR, Dienelt MM, Owens RA, Hammond J. Mutation of a chloroplast-targeting signal in Alternanthera mosaic virus TGB3 impairs cell-to-cell movement and eliminates long-distance virus movement. J Gen Virol 2010; 91:2102-2115. [PMID: 20392901 DOI: 10.1099/vir.0.019448-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Cell-to-cell movement of potexviruses requires coordinated action of the coat protein and triple gene block (TGB) proteins. The structural properties of Alternanthera mosaic virus (AltMV) TGB3 were examined by methods differentiating between signal peptides and transmembrane domains, and its subcellular localization was studied by Agrobacterium-mediated transient expression and confocal microscopy. Unlike potato virus X (PVX) TGB3, AltMV TGB3 was not associated with the endoplasmic reticulum, and accumulated preferentially in mesophyll cells. Deletion and site-specific mutagenesis revealed an internal signal VL(17,18) of TGB3 essential for chloroplast localization, and either deletion of the TGB3 start codon or alteration of the chloroplast-localization signal limited cell-to-cell movement to the epidermis, yielding a virus that was unable to move into the mesophyll layer. Overexpression of AltMV TGB3 from either AltMV or PVX infectious clones resulted in veinal necrosis and vesiculation at the chloroplast membrane, a cytopathology not observed in wild-type infections. The distinctive mesophyll and chloroplast localization of AltMV TGB3 highlights the critical role played by mesophyll targeting in virus long-distance movement within plants.
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Affiliation(s)
- Hyoun-Sub Lim
- USDA-ARS, Plant Sciences Institute, Molecular Plant Pathology Laboratory, B-004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - Anna Maria Vaira
- CNR, Istituto di Virologia Vegetale, Strada delle Cacce 73, Torino 10135, Italy
- USDA-ARS, Plant Sciences Institute, Molecular Plant Pathology Laboratory, B-004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - Hanhong Bae
- School of Biotechnology, Yeungnam University, Geongsan 712-749, Republic of Korea
| | - Jennifer N Bragg
- USDA-ARS, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
| | - Steven E Ruzin
- University of California-Berkeley, CNR, 381 Koshland Hall, Berkeley, CA 94720, USA
| | - Gary R Bauchan
- USDA-ARS, Plant Sciences Institute, Electron and Confocal Microscopy Unit, B-465, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - Margaret M Dienelt
- USDA-ARS, Plant Sciences Institute, Molecular Plant Pathology Laboratory, B-004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - Robert A Owens
- USDA-ARS, Plant Sciences Institute, Molecular Plant Pathology Laboratory, B-004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
| | - John Hammond
- USDA-ARS, Plant Sciences Institute, Molecular Plant Pathology Laboratory, B-004, 10300 Baltimore Avenue, Beltsville, MD 20705, USA
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Wei T, Zhang C, Hong J, Xiong R, Kasschau KD, Zhou X, Carrington JC, Wang A. Formation of complexes at plasmodesmata for potyvirus intercellular movement is mediated by the viral protein P3N-PIPO. PLoS Pathog 2010; 6:e1000962. [PMID: 20585568 PMCID: PMC2891837 DOI: 10.1371/journal.ppat.1000962] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 05/24/2010] [Indexed: 01/08/2023] Open
Abstract
Intercellular transport of viruses through cytoplasmic connections, termed plasmodesmata (PD), is essential for systemic infection in plants by viruses. Previous genetic and ultrastructural data revealed that the potyvirus cyclindrical inclusion (CI) protein is directly involved in cell-to-cell movement, likely through the formation of conical structures anchored to and extended through PD. In this study, we demonstrate that plasmodesmatal localization of CI in N. benthamiana leaf cells is modulated by the recently discovered potyviral protein, P3N-PIPO, in a CI:P3N-PIPO ratio-dependent manner. We show that P3N-PIPO is a PD-located protein that physically interacts with CI in planta. The early secretory pathway, rather than the actomyosin motility system, is required for the delivery of P3N-PIPO and CI to PD. Moreover, CI mutations that disrupt virus cell-to-cell movement compromise PD-localization capacity. These data suggest that the CI and P3N-PIPO complex coordinates the formation of PD-associated structures that facilitate the intercellular movement of potyviruses in infected plants.
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Affiliation(s)
- Taiyun Wei
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - Changwei Zhang
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
- College of Horticulture, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Jian Hong
- Center of Analysis and Measurement, Zhejiang University, Hangzhou, People's Republic of China
| | - Ruyi Xiong
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Kristin D. Kasschau
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Xueping Zhou
- Institute of Biotechnology, Zhejiang University, Hangzhou, People's Republic of China
| | - James C. Carrington
- Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Aiming Wang
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
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Yu XQ, Jia JL, Zhang CL, Li XD, Wang YJ. Phylogenetic analyses of an isolate obtained from potato in 1985 revealed potato virus X was introduced to China via multiple events. Virus Genes 2010; 40:447-51. [PMID: 20221681 DOI: 10.1007/s11262-010-0468-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2010] [Accepted: 02/27/2010] [Indexed: 11/24/2022]
Abstract
Potato virus X (PVX) is one of the most common plant viruses that cause great economic losses to solanaceous plants. We have previously reported the complete genomic sequence of the 2006 Chinese potato isolate FX21 and demonstrated that PVX isolates cluster into two groups: Eurasia and America. Here, we present the complete genomic sequence of one PVX isolate collected from potato in 1985 (PVX-1985). The genome of PVX-1985 is identical to that of FX21 in length and has the same genomic structure. PVX-1985, which like FX21 fell within the Eurasia group, clustered together with isolates from Europe, whereas FX21 clustered together with isolates of primarily Asian origin. Phylogenetic analyses of the complete genomic sequences and of CP gene sequences showed that Chinese PVX isolates have different origins and were introduced via multiple events. Though all the open reading frames of PVX are under negative/purifying selection, the central region of RNA-dependent RNA polymerase is under positive/diversifying selection.
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Affiliation(s)
- Xiao-Qing Yu
- Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, China
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Arabidopsis synaptotagmin SYTA regulates endocytosis and virus movement protein cell-to-cell transport. Proc Natl Acad Sci U S A 2010; 107:2491-6. [PMID: 20133785 DOI: 10.1073/pnas.0909080107] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Synaptotagmins are calcium sensors that regulate synaptic vesicle exo/endocytosis. Thought to be exclusive to animals, they have recently been characterized in plants. We show that Arabidopsis synaptotagmin SYTA regulates endosome recycling and movement protein (MP)-mediated trafficking of plant virus genomes through plasmodesmata. SYTA localizes to endosomes in plant cells and directly binds the distinct Cabbage leaf curl virus (CaLCuV) and Tobacco mosaic virus (TMV) cell-to-cell movement proteins. In a SYTA knockdown line, CaLCuV systemic infection is delayed, and cell-to-cell spread of TMV and CaLCuV movement proteins is inhibited. A dominant-negative SYTA mutant causes depletion of plasma membrane-derived endosomes, produces large intracellular vesicles attached to plasma membrane, and inhibits cell-to-cell trafficking of TMV and CaLCuV movement proteins, when tested in an Agrobacterium-based leaf expression assay. Our studies show that SYTA regulates endocytosis, and suggest that distinct virus movement proteins transport their cargos to plasmodesmata for cell-to-cell spread via an endocytic recycling pathway.
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45
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Gómez P, Sempere RN, Elena SF, Aranda MA. Mixed infections of Pepino mosaic virus strains modulate the evolutionary dynamics of this emergent virus. J Virol 2009; 83:12378-87. [PMID: 19759144 PMCID: PMC2786733 DOI: 10.1128/jvi.01486-09] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 09/10/2009] [Indexed: 11/20/2022] Open
Abstract
Pepino mosaic virus (PepMV) is an emerging pathogen that causes severe economic losses in tomato crops (Solanum lycopersicum L.) in the Northern hemisphere, despite persistent attempts of control. In fact, it is considered one of the most significant viral diseases for tomato production worldwide, and it may constitute a good model for the analysis of virus emergence in crops. We have combined a population genetics approach with an analysis of in planta properties of virus strains to explain an observed epidemiological pattern. Hybridization analysis showed that PepMV populations are composed of isolates of two types (PepMV-CH2 and PepMV-EU) that cocirculate. The CH2 type isolates are predominant; however, EU isolates have not been displaced but persist mainly in mixed infections. Two molecularly cloned isolates belonging to each type have been used to examine the dynamics of in planta single infections and coinfection, revealing that the CH2 type has a higher fitness than the EU type. Coinfections expand the range of susceptible hosts, and coinfected plants remain symptomless several weeks after infection, so a potentially important problem for disease prevention and management. These results provide an explanation of the observed epidemiological pattern in terms of genetic and ecological interactions among the different viral strains. Thus, mixed infections appear to be contributing to shaping the genetic structure and dynamics of PepMV populations.
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Affiliation(s)
- P. Gómez
- Centro de Edafología y Biología Aplicada del Segura, Consejo Superior de Investigaciones Científicas, Apdo. Correos 164, 30100 Espinardo (Murcia), Spain, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, 46022 Valencia, Spain, The Santa Fe Institute, Santa Fe, New Mexico 87501
| | - R. N. Sempere
- Centro de Edafología y Biología Aplicada del Segura, Consejo Superior de Investigaciones Científicas, Apdo. Correos 164, 30100 Espinardo (Murcia), Spain, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, 46022 Valencia, Spain, The Santa Fe Institute, Santa Fe, New Mexico 87501
| | - S. F. Elena
- Centro de Edafología y Biología Aplicada del Segura, Consejo Superior de Investigaciones Científicas, Apdo. Correos 164, 30100 Espinardo (Murcia), Spain, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, 46022 Valencia, Spain, The Santa Fe Institute, Santa Fe, New Mexico 87501
| | - M. A. Aranda
- Centro de Edafología y Biología Aplicada del Segura, Consejo Superior de Investigaciones Científicas, Apdo. Correos 164, 30100 Espinardo (Murcia), Spain, Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-UPV, 46022 Valencia, Spain, The Santa Fe Institute, Santa Fe, New Mexico 87501
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46
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Everett AL, Scholthof HB, Scholthof KBG. Satellite panicum mosaic virus coat protein enhances the performance of plant virus gene vectors. Virology 2009; 396:37-46. [PMID: 19903565 DOI: 10.1016/j.virol.2009.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/09/2009] [Accepted: 10/03/2009] [Indexed: 01/16/2023]
Abstract
The coat protein of satellite panicum mosaic virus (SPCP) is known to effectively protect its cognate RNA from deleterious events, and here, we tested its stabilizing potential for heterologous virus-based gene vectors in planta. In support of this, a Potato virus X (PVX) vector carrying the SPMV capsid protein (PVX-SPCP) gene was stable for at least three serial systemic passages through Nicotiana benthamiana. To test the effect of SPCP in trans, PVX-SPCP was co-inoculated onto N. benthamiana together with a Tomato bushy stunt virus (TBSV) vector carrying a green fluorescent protein (GFP) gene that normally does not support systemic GFP expression. In contrast, co-inoculation of TBSV-GFP plus PVX-SPCP resulted in GFP accumulation and concomitant green fluorescent spots in upper, non-inoculated leaves in a temperature-responsive manner. These results suggest that the multifaceted SPMV CP has intriguing effects on virus-host interactions that surface in heterologous systems.
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Affiliation(s)
- Anthany L Everett
- Department of Plant Pathology and Microbiology, 2132 TAMU, Texas A&M University, College Station, TX 77843, USA
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47
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Lim HS, Bragg JN, Ganesan U, Ruzin S, Schichnes D, Lee MY, Vaira AM, Ryu KH, Hammond J, Jackson AO. Subcellular localization of the barley stripe mosaic virus triple gene block proteins. J Virol 2009; 83:9432-48. [PMID: 19570874 PMCID: PMC2738231 DOI: 10.1128/jvi.00739-09] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 06/22/2009] [Indexed: 02/07/2023] Open
Abstract
Barley stripe mosaic virus (BSMV) spreads from cell to cell through the coordinated actions of three triple gene block (TGB) proteins (TGB1, TGB2, and TGB3) arranged in overlapping open reading frames (ORFs). Our previous studies (D. M. Lawrence and A. O. Jackson, J. Virol. 75:8712-8723, 2001; D. M. Lawrence and A. O. Jackson, Mol. Plant Pathol. 2:65-75, 2001) have shown that each of these proteins is required for cell-to-cell movement in monocot and dicot hosts. We recently found (H.-S. Lim, J. N. Bragg, U. Ganesan, D. M. Lawrence, J. Yu, M. Isogai, J. Hammond, and A. O. Jackson, J. Virol. 82:4991-5006, 2008) that TGB1 engages in homologous interactions leading to the formation of a ribonucleoprotein complex containing viral genomic and messenger RNAs, and we have also demonstrated that TGB3 functions in heterologous interactions with TGB1 and TGB2. We have now used Agrobacterium tumefaciens-mediated protein expression in Nicotiana benthamiana leaf cells and site-specific mutagenesis to determine how TGB protein interactions influence their subcellular localization and virus spread. Confocal microscopy revealed that the TGB3 protein localizes at the cell wall (CW) in close association with plasmodesmata and that the deletion or mutagenesis of a single amino acid at the immediate C terminus can affect CW targeting. TGB3 also directed the localization of TGB2 from the endoplasmic reticulum to the CW, and this targeting was shown to be dependent on interactions between the TGB2 and TGB3 proteins. The optimal localization of the TGB1 protein at the CW also required TGB2 and TGB3 interactions, but in this context, site-specific TGB1 helicase motif mutants varied in their localization patterns. The results suggest that the ability of TGB1 to engage in homologous binding interactions is not essential for targeting to the CW. However, the relative expression levels of TGB2 and TGB3 influenced the cytosolic and CW distributions of TGB1 and TGB2. Moreover, in both cases, localization at the CW was optimal at the 10:1 TGB2-to-TGB3 ratios occurring in virus infections, and mutations reducing CW localization had corresponding effects on BSMV movement phenotypes. These data support a model whereby TGB protein interactions function in the subcellular targeting of movement protein complexes and the ability of BSMV to move from cell to cell.
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Affiliation(s)
- Hyoun-Sub Lim
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Jennifer N. Bragg
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Uma Ganesan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Steven Ruzin
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Denise Schichnes
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Mi Yeon Lee
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Anna Maria Vaira
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Ki Hyun Ryu
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - John Hammond
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
| | - Andrew O. Jackson
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, FNPRU, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland 20705, CNR, Istituto di Virologia Vegetale, Torino 10135, Italy, Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, South Korea
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Liu C, Meng C, Xie L, Hong J, Zhou X. Cell-to-cell trafficking, subcellular distribution, and binding to coat protein of Broad bean wilt virus 2 VP37 protein. Virus Res 2009; 143:86-93. [PMID: 19463725 DOI: 10.1016/j.virusres.2009.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 03/10/2009] [Accepted: 03/15/2009] [Indexed: 12/23/2022]
Abstract
Broad bean wilt virus 2 (BBWV 2) is a member of the genus Fabavirus of the family Comoviridae. To date, a movement protein (MP) of BBWV 2 has not been described. Here we demonstrate that the green fluorescent protein (GFP)-VP37 fusion protein can move from initial bombarded cells to neighboring cells in Nicotiana benthamiana epidermal leaves. In addition, the GFP-VP37 fusion protein localizes as a halo around the nucleus and as punctate spots on the cell periphery in N. benthamiana epidermal leaf cells and BY-2 suspension cells. Fluorescence near the nucleus also was co-localized with the endoplasmic reticulum in BY-2 cells. Fibrous networks were found in GFP-VP37 agro-infiltrated N. benthamiana epidermal leaf cells. Deletion analyses indicated that the C-terminal region of the VP37 protein is essential for localization at the cell periphery. Using a blot overlay assay and bimolecular fluorescence complementation assay, the purified 6xHis-tagged VP37 protein was shown to bind specifically to the small coat protein of BBWV 2. The above results indicate that VP37 is a movement protein.
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Affiliation(s)
- Chengke Liu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310029, People's Republic of China
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49
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Ozeki J, Hashimoto M, Komatsu K, Maejima K, Himeno M, Senshu H, Kawanishi T, Kagiwada S, Yamaji Y, Namba S. The N-terminal region of the Plantago asiatica mosaic virus coat protein is required for cell-to-cell movement but is dispensable for virion assembly. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:677-85. [PMID: 19445592 DOI: 10.1094/mpmi-22-6-0677] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Potexvirus cell-to-cell movement requires coat protein (CP) and movement proteins. In this study, mutations in two conserved in-frame AUG codons in the 5' region of the CP open reading frame of Plantago asiatica mosaic virus (PlAMV) were introduced, and virus accumulation of these mutants was analyzed in inoculated and upper noninoculated leaves. When CP was translated only from the second AUG codon, virus accumulation in inoculated leaves was lower than that of wild-type PlAMV, and the viral spread was impaired. Trans-complementation analysis showed that the leucine residue at the third position (Leu-3) of CP is important for cell-to-cell movement of PlAMV. The 14-amino-acid N-terminal region of CP was dispensable for virion formation. Immunoprecipitation assays conducted with an anti-TGBp1 antibody indicated that PlAMV CP interacts with TGBp1 in vivo and that this interaction is not affected by alanine substitution at Leu-3. These results support the concept that the N-terminal region of potexvirus CP can be separated into two distinct functional domains.
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Affiliation(s)
- Johji Ozeki
- Laboratory of Plant Pathology, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo
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Lu HC, Chen CE, Tsai MH, Wang HI, Su HJ, Yeh HH. Cymbidium mosaic potexvirus isolate-dependent host movement systems reveal two movement control determinants and the coat protein is the dominant. Virology 2009; 388:147-59. [PMID: 19345971 PMCID: PMC7103407 DOI: 10.1016/j.virol.2009.02.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 01/28/2009] [Accepted: 02/28/2009] [Indexed: 11/30/2022]
Abstract
Little is known about how plant viruses of a single species exhibit different movement behavior in different host species. Two Cymbidium mosaic potexvirus (CymMV) isolates, M1 and M2, were studied. Both can infect Phalaenopsis orchids, but only M1 can systemically infect Nicotiana benthamiana plants. Protoplast inoculation and whole-mount in situ hybridization revealed that both isolates can replicate in N. benthamiana; however, M2 was restricted to the initially infected cells. Genome shuffling between M1 and M2 revealed that two control modes are involved in CymMV host dependent movement. The M1 coat protein (CP) plays a dominant role in controlling CymMV movement between cells, because all chimeric CymMV viruses containing the M1 CP systemically infected N. benthamiana plants. Without the M1 CP, one chimeric virus containing the combination of the M1 triple gene block proteins (TGBps), the M2 5' RNA (1-4333), and the M2 CP effectively moved in N. benthamiana plants. Further complementation analysis revealed that M1 TGBp1 and TGBp3 are co-required to complement the movement of the chimeric viruses in N. benthamiana. The amino acids within the CP, TGBp1 and TGBp3 which are required or important for CymMV M2 movement in N. benthamiana plants were mapped. The required amino acids within the CP map to the predicted RNA binding domain. RNA-protein binding assays revealed that M1 CP has higher RNA binding affinity than does M2 CP. Yeast two-hybrid assays to detect all possible interactions of M1 TGBps and CP, and only TGBp1 and CP self-interactions were observed.
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Affiliation(s)
- Hsiang-Chia Lu
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Cheng-En Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Meng-Hsiun Tsai
- Department of Management Information Systems, National Chung Hsing University, 250, Kuo Kuang Rd., Taichung 402, Taiwan
| | - Hsiang-iu Wang
- Department of Computer Science, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
| | - Hong-Ji Su
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
| | - Hsin-Hung Yeh
- Department of Plant Pathology and Microbiology, National Taiwan University, 1, sec 4, Roosevelt Road, Taipei 106, Taiwan
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