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Sun D, Li Y, Ma Z, Yan X, Li N, Shang B, Hu X, Cui K, Koiwa H, Zhang X. The epigenetic factor FVE orchestrates cytoplasmic SGS3-DRB4-DCL4 activities to promote transgene silencing in Arabidopsis. SCIENCE ADVANCES 2021; 7:7/32/eabf3898. [PMID: 34348894 PMCID: PMC8336953 DOI: 10.1126/sciadv.abf3898] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 06/15/2021] [Indexed: 05/27/2023]
Abstract
Posttranscriptional gene silencing (PTGS) is a regulatory mechanism to suppress undesired transcripts. Here, we identified Flowering locus VE (FVE), a well-known epigenetic component, as a new player in cytoplasmic PTGS. Loss-of-function fve mutations substantially reduced the accumulation of transgene-derived small interfering RNAs (siRNAs). FVE interacts with suppressor of gene silencing 3 (SGS3), a master component in PTGS. FVE promotes SGS3 homodimerization that is essential for its function. FVE can bind to single-stranded RNA and double-stranded RNA (dsRNA) with moderate affinities, while its truncated form FVE-8 has a significantly increased binding affinity to dsRNA. These affinities affect the association and channeling of SGS3-RNA to downstream dsRNA binding protein 4 (DRB4)/Dicer-like protein 2/4 (DCL2/4) complexes. Hence, FVE, but not FVE-8, biochemically enhances the DRB4/DCL2/4 activity in vitro. We surmise that FVE promotes production of transgene-derived siRNAs through concertedly tuning SGS3-DRB4/DCL2/4 functions. Thus, this study revealed a noncanonical role of FVE in PTGS.
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Affiliation(s)
- Di Sun
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Yanjun Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Zeyang Ma
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Xingxing Yan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Niankui Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Baoshuan Shang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Xiaomei Hu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
| | - Kai Cui
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China
| | - Hisashi Koiwa
- Department of Horticultural Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA.
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Ambrós S, Gómez-Muñoz N, Giménez-Santamarina S, Sánchez-Vicente J, Navarro-López J, Martínez F, Daròs JA, Rodrigo G. Molecular signatures of silencing suppression degeneracy from a complex RNA virus. PLoS Comput Biol 2021; 17:e1009166. [PMID: 34181647 PMCID: PMC8270454 DOI: 10.1371/journal.pcbi.1009166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 07/09/2021] [Accepted: 06/09/2021] [Indexed: 11/21/2022] Open
Abstract
As genomic architectures become more complex, they begin to accumulate degenerate and redundant elements. However, analyses of the molecular mechanisms underlying these genetic architecture features remain scarce, especially in compact but sufficiently complex genomes. In the present study, we followed a proteomic approach together with a computational network analysis to reveal molecular signatures of protein function degeneracy from a plant virus (as virus-host protein-protein interactions). We employed affinity purification coupled to mass spectrometry to detect several host factors interacting with two proteins of Citrus tristeza virus (p20 and p25) that are known to function as RNA silencing suppressors, using an experimental system of transient expression in a model plant. The study was expanded by considering two different isolates of the virus, and some key interactions were confirmed by bimolecular fluorescence complementation assays. We found that p20 and p25 target a common set of plant proteins including chloroplastic proteins and translation factors. Moreover, we noted that even specific targets of each viral protein overlap in function. Notably, we identified argonaute proteins (key players in RNA silencing) as reliable targets of p20. Furthermore, we found that these viral proteins preferentially do not target hubs in the host protein interactome, but elements that can transfer information by bridging different parts of the interactome. Overall, our results demonstrate that two distinct proteins encoded in the same viral genome that overlap in function also overlap in their interactions with the cell proteome, thereby highlighting an overlooked connection from a degenerate viral system.
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Affiliation(s)
- Silvia Ambrós
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Spain
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
- Instituto de Biología Integrativa de Sistemas (I2SysBio), CSIC–Universitat de València, Paterna, Spain
| | - Neus Gómez-Muñoz
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Spain
| | - Silvia Giménez-Santamarina
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
| | - Javier Sánchez-Vicente
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
| | - Josep Navarro-López
- Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Moncada, Spain
| | - Fernando Martínez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
| | - Guillermo Rodrigo
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), CSIC–Universitat Politècnica de València, València, Spain
- Instituto de Biología Integrativa de Sistemas (I2SysBio), CSIC–Universitat de València, Paterna, Spain
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53
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Decle-Carrasco S, Rodríguez-Zapata LC, Castano E. Plant viral proteins and fibrillarin: the link to complete the infective cycle. Mol Biol Rep 2021; 48:4677-4686. [PMID: 34036480 DOI: 10.1007/s11033-021-06401-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
Abstract
The interaction between viruses with the nucleolus is already a well-defined field of study in plant virology. This interaction is not restricted to those viruses that replicate in the nucleus, in fact, RNA viruses that replicate exclusively in the cytoplasm express proteins that localize in the nucleolus. Some positive single stranded RNA viruses from animals and plants have been reported to interact with the main nucleolar protein, Fibrillarin. Among nucleolar proteins, Fibrillarin is an essential protein that has been conserved in sequence and function throughout evolution. Fibrillarin is a methyltransferase protein with more than 100 methylation sites in the pre-ribosomal RNA, involved in multiple cellular processes, including initiation of transcription, oncogenesis, and apoptosis, among others. Recently, it was found that AtFib2 shows a ribonuclease activity. In plant viruses, Fibrillarin is involved in long-distance movement and cell-to-cell movement, being two highly different processes. The mechanism that Fibrillarin performs is still unknown. However, and despite belonging to very different viral families, the majority comply with the following. (1) They are positive single stranded RNA viruses; (2) encode different types of viral proteins that partially localize in the nucleolus; (3) interacts with Fibrillarin exporting it to the cytoplasm; (4) the viral protein-Fibrillarin interaction forms an RNP complex with the viral RNA and; (5) Fibrillarin depletion affects the infective cycle of the virus. Here we review the relationship of those plant viruses with Fibrillarin interaction, with special focus on the molecular processes of the virus to sequester Fibrillarin to complete its infective cycle.
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Affiliation(s)
- Stefano Decle-Carrasco
- Unidad de Bioquímica y Biología Molecular de Plantas. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México
| | - Luis Carlos Rodríguez-Zapata
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México
| | - Enrique Castano
- Unidad de Bioquímica y Biología Molecular de Plantas. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México.
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54
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Decle-Carrasco S, Rodríguez-Zapata LC, Castano E. Plant viral proteins and fibrillarin: the link to complete the infective cycle. Mol Biol Rep 2021. [PMID: 34036480 DOI: 10.1007/s11033-021-06401-1/tables/1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
The interaction between viruses with the nucleolus is already a well-defined field of study in plant virology. This interaction is not restricted to those viruses that replicate in the nucleus, in fact, RNA viruses that replicate exclusively in the cytoplasm express proteins that localize in the nucleolus. Some positive single stranded RNA viruses from animals and plants have been reported to interact with the main nucleolar protein, Fibrillarin. Among nucleolar proteins, Fibrillarin is an essential protein that has been conserved in sequence and function throughout evolution. Fibrillarin is a methyltransferase protein with more than 100 methylation sites in the pre-ribosomal RNA, involved in multiple cellular processes, including initiation of transcription, oncogenesis, and apoptosis, among others. Recently, it was found that AtFib2 shows a ribonuclease activity. In plant viruses, Fibrillarin is involved in long-distance movement and cell-to-cell movement, being two highly different processes. The mechanism that Fibrillarin performs is still unknown. However, and despite belonging to very different viral families, the majority comply with the following. (1) They are positive single stranded RNA viruses; (2) encode different types of viral proteins that partially localize in the nucleolus; (3) interacts with Fibrillarin exporting it to the cytoplasm; (4) the viral protein-Fibrillarin interaction forms an RNP complex with the viral RNA and; (5) Fibrillarin depletion affects the infective cycle of the virus. Here we review the relationship of those plant viruses with Fibrillarin interaction, with special focus on the molecular processes of the virus to sequester Fibrillarin to complete its infective cycle.
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Affiliation(s)
- Stefano Decle-Carrasco
- Unidad de Bioquímica y Biología Molecular de Plantas. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México
| | - Luis Carlos Rodríguez-Zapata
- Unidad de Biotecnología. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México
| | - Enrique Castano
- Unidad de Bioquímica y Biología Molecular de Plantas. Centro de Investigación Científica de Yucatán, A.C. Calle 43 No. 130, Colonia Chuburná de Hidalgo, Mérida, Yucatán, México.
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55
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Huang C. From Player to Pawn: Viral Avirulence Factors Involved in Plant Immunity. Viruses 2021; 13:v13040688. [PMID: 33923435 PMCID: PMC8073968 DOI: 10.3390/v13040688] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/09/2021] [Accepted: 04/14/2021] [Indexed: 02/07/2023] Open
Abstract
In the plant immune system, according to the 'gene-for-gene' model, a resistance (R) gene product in the plant specifically surveils a corresponding effector protein functioning as an avirulence (Avr) gene product. This system differs from other plant-pathogen interaction systems, in which plant R genes recognize a single type of gene or gene family because almost all virus genes with distinct structures and functions can also interact with R genes as Avr determinants. Thus, research conducted on viral Avr-R systems can provide a novel understanding of Avr and R gene product interactions and identify mechanisms that enable rapid co-evolution of plants and phytopathogens. In this review, we intend to provide a brief overview of virus-encoded proteins and their roles in triggering plant resistance, and we also summarize current progress in understanding plant resistance against virus Avr genes. Moreover, we present applications of Avr gene-mediated phenotyping in R gene identification and screening of segregating populations during breeding processes.
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Affiliation(s)
- Changjun Huang
- Key Laboratory of Tobacco Biotechnological Breeding, National Tobacco Genetic Engineering Research Center, Yunnan Academy of Tobacco Agricultural Sciences, Kunming 650021, China
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56
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Overexpression of an insect virus encoded silencing suppressor does not enhance plants' susceptibility to its natural virus. Virusdisease 2021; 32:338-342. [PMID: 34350319 DOI: 10.1007/s13337-020-00644-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 11/27/2020] [Indexed: 10/21/2022] Open
Abstract
RNA silencing plays a key role in shielding plant and animal hosts against viral invasion and infection. Viruses encode RNA silencing suppressors (RSS) to block small RNA guided silencing of viral transcripts. The B2 protein encoded by Flock House virus (FHV) is a well-characterized RSS that facilitates infection in insects. It has been shown to act as a functional RSS in plants. FHVB2 over-expressing tobacco plants were used to study the effect of RSS on plant susceptibility to Tobacco mosaic virus (TMV), its natural pathogen. The major symptoms observed in TMV-infected transgenic plants were greenish mosaic, puckering and distortion of leaves, but the infected transgenic leaves were able to resist chlorophyll loss. The infected leaves of transgenic plants showed no significant difference in accumulation of virus when compared with that of the wild type plants. FHVB2 plants showed higher levels of H2O2 and the ROS scavenging enzymes, APX and SOD. This suggests that interference of FHVB2 with RNA silencing machinery may activate alternative defense pathways in the plants so that they are not overly sensitive to TMV infection. Supplementary Information The online version contains supplementary material available at 10.1007/s13337-020-00644-5.
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57
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The role of miRNA in plant-virus interaction: a review. Mol Biol Rep 2021; 48:2853-2861. [PMID: 33772417 DOI: 10.1007/s11033-021-06290-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 03/13/2021] [Indexed: 01/20/2023]
Abstract
Plant viruses affect crop production both quantitatively and qualitatively. The viral genome consists of either DNA or RNA. However, most plant viruses are positive single-strand RNA viruses. MicroRNAs are involved in gene regulation and affect development as well as host-virus interaction. They are non-coding short with 20-24 nucleotides long capable of regulating gene expression. The miRNA gene is transcribed by RNA polymerase II to form pri-miRNA which will later cleaved by Dicer-like 1 to produce pre-miRNA with the help of HYPONASTIC LEAVES1 and SERRATE which finally methylated and exported via nucleopore with the help of HASTY. The outcome of plant virus interaction depends on the effectiveness of host defense and the ability of a virus counter-defense mechanism. In plants, miRNAs are involved in the repression of gene expression through transcript cleavage. On the other hand, viruses use viral suppressors of RNA silencing (VSRs) which affect RISC assembly and subsequent mRNA degradation. Passenger strands, miRNA*, have a significant biological function in plant defense response as well as plant development.
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58
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Soltani N, Staton M, Gwinn KD. Response of bitter and sweet Chenopodium quinoa varieties to cucumber mosaic virus: Transcriptome and small RNASeq perspective. PLoS One 2021; 16:e0244364. [PMID: 33621238 PMCID: PMC7901783 DOI: 10.1371/journal.pone.0244364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/08/2020] [Indexed: 12/25/2022] Open
Abstract
Saponins are secondary metabolites with antiviral properties. Low saponin (sweet) varieties of quinoa (Chenopodium quinoa) have been developed because seeds high in saponins taste bitter. The aim of this study was to elucidate the role of saponin in resistance of quinoa to Cucumber mosaic virus (CMV). Differential gene expression was studied in time-series study of CMV infection. High-throughput transcriptome sequence data were obtained from 36 samples (3 varieties × +/- CMV × 1 or 4 days after inoculation × 3 replicates). Translation, lipid, nitrogen, amino acid metabolism, and mono- and sesquiterpenoid biosynthesis genes were upregulated in CMV infections. In 'Red Head' (bitter), CMV-induced systemic symptoms were concurrent with downregulation of a key saponin biosynthesis gene, TSARL1, four days after inoculation. In local lesion responses (sweet and semi-sweet), TSARL1 levels remained up-regulated. Known microRNAs (miRNA) (81) from 11 miR families and 876 predicted novel miRNAs were identified. Differentially expressed miRNA and short interfering RNA clusters (24nt) induced by CMV infection are predicted to target genomic and intergenic regions enriched in repetitive elements. This is the first report of integrated RNASeq and sRNASeq data in quinoa-virus interactions and provides comprehensive understanding of involved genes, non-coding regions, and biological pathways in virus resistance.
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Affiliation(s)
- Nourolah Soltani
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America
- Department of Plant Pathology, University of California-Davis, Davis, California, United States of America
| | - Margaret Staton
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Kimberly D. Gwinn
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, United States of America
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59
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Leonetti P, Ghasemzadeh A, Consiglio A, Gursinsky T, Behrens S, Pantaleo V. Endogenous activated small interfering RNAs in virus-infected Brassicaceae crops show a common host gene-silencing pattern affecting photosynthesis and stress response. THE NEW PHYTOLOGIST 2021; 229:1650-1664. [PMID: 32945560 PMCID: PMC7821159 DOI: 10.1111/nph.16932] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/04/2020] [Indexed: 05/14/2023]
Abstract
Viral infections are accompanied by a massive production of small interfering RNAs (siRNAs) of plant origin, such as virus-activated (va)siRNAs, which drive the widespread silencing of host gene expression, and whose effects in plant pathogen interactions remain unknown. By combining phenotyping and molecular analyses, we characterized vasiRNAs that are associated with typical mosaic symptoms of cauliflower mosaic virus infection in two crops, turnip (Brassica rapa) and oilseed rape (Brassica napus), and the reference plant Arabidopsis thaliana. We identified 15 loci in the three infected plant species, whose transcripts originate vasiRNAs. These loci appear to be generally affected by virus infections in Brassicaceae and encode factors that are centrally involved in photosynthesis and stress response, such as Rubisco activase (RCA), senescence-associated protein, heat shock protein HSP70, light harvesting complex, and membrane-related protein CP5. During infection, the expression of these factors is significantly downregulated, suggesting that their silencing is a central component of the plant's response to virus infections. Further findings indicate an important role for 22 nt long vasiRNAs in the plant's endogenous RNA silencing response. Our study considerably enhances knowledge about the new class of vasiRNAs that are triggered in virus-infected plants and will help to advance strategies for the engineering of gene clusters involved in the development of crop diseases.
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Affiliation(s)
- Paola Leonetti
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
| | - Aysan Ghasemzadeh
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
- Department of Plant PathologyFaculty of AgricultureTarbiat Modares UniversityTehran14115‐111Iran
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Arianna Consiglio
- Department of Biomedical SciencesInstitute for Biomedical TechnologiesBari UnitCNRBari70126Italy
| | - Torsten Gursinsky
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Sven‐Erik Behrens
- Institute of Biochemistry and Biotechnology (NFI)Section Microbial BiotechnologyMartin Luther University Halle‐WittenbergHalle/SaaleD‐06120Germany
| | - Vitantonio Pantaleo
- Department of Biology, Agricultural and Food SciencesInstitute for Sustainable Plant ProtectionBari UnitCNRBari70126Italy
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60
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Ramesh SV, Yogindran S, Gnanasekaran P, Chakraborty S, Winter S, Pappu HR. Virus and Viroid-Derived Small RNAs as Modulators of Host Gene Expression: Molecular Insights Into Pathogenesis. Front Microbiol 2021; 11:614231. [PMID: 33584579 PMCID: PMC7874048 DOI: 10.3389/fmicb.2020.614231] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/19/2020] [Indexed: 02/01/2023] Open
Abstract
Virus-derived siRNAs (vsiRNAs) generated by the host RNA silencing mechanism are effectors of plant’s defense response and act by targeting the viral RNA and DNA in post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) pathways, respectively. Contrarily, viral suppressors of RNA silencing (VSRs) compromise the host RNA silencing pathways and also cause disease-associated symptoms. In this backdrop, reports describing the modulation of plant gene(s) expression by vsiRNAs via sequence complementarity between viral small RNAs (sRNAs) and host mRNAs have emerged. In some cases, silencing of host mRNAs by vsiRNAs has been implicated to cause characteristic symptoms of the viral diseases. Similarly, viroid infection results in generation of sRNAs, originating from viroid genomic RNAs, that potentially target host mRNAs causing typical disease-associated symptoms. Pathogen-derived sRNAs have been demonstrated to have the propensity to target wide range of genes including host defense-related genes, genes involved in flowering and reproductive pathways. Recent evidence indicates that vsiRNAs inhibit host RNA silencing to promote viral infection by acting as decoy sRNAs. Nevertheless, it remains unclear if the silencing of host transcripts by viral genome-derived sRNAs are inadvertent effects due to fortuitous pairing between vsiRNA and host mRNA or the result of genuine counter-defense strategy employed by viruses to enhance its survival inside the plant cell. In this review, we analyze the instances of such cross reaction between pathogen-derived vsiRNAs and host mRNAs and discuss the molecular insights regarding the process of pathogenesis.
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Affiliation(s)
- S V Ramesh
- ICAR-Central Plantation Crops Research Institute, Kasaragod, India
| | - Sneha Yogindran
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Prabu Gnanasekaran
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
| | | | - Stephan Winter
- Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany
| | - Hanu R Pappu
- Department of Plant Pathology, Washington State University, Pullman, WA, United States
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61
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Ando S, Jaskiewicz M, Mochizuki S, Koseki S, Miyashita S, Takahashi H, Conrath U. Priming for enhanced ARGONAUTE2 activation accompanies induced resistance to cucumber mosaic virus in Arabidopsis thaliana. MOLECULAR PLANT PATHOLOGY 2021; 22:19-30. [PMID: 33073913 PMCID: PMC7749747 DOI: 10.1111/mpp.13005] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 05/29/2023]
Abstract
Systemic acquired resistance (SAR) is a broad-spectrum disease resistance response that can be induced upon infection from pathogens or by chemical treatment, such as with benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH). SAR involves priming for more robust activation of defence genes upon pathogen attack. Whether priming for SAR would involve components of RNA silencing remained unknown. Here, we show that upon leaf infiltration of water, BTH-primed Arabidopsis thaliana plants accumulate higher amounts of mRNA of ARGONAUTE (AGO)2 and AGO3, key components of RNA silencing. The enhanced AGO2 expression is associated with prior-to-activation trimethylation of lysine 4 in histone H3 and acetylation of histone H3 in the AGO2 promoter and with induced resistance to the yellow strain of cucumber mosaic virus (CMV[Y]). The results suggest that priming A. thaliana for enhanced defence involves modification of histones in the AGO2 promoter that condition AGO2 for enhanced activation, associated with resistance to CMV(Y). Consistently, the fold-reduction in CMV(Y) coat protein accumulation by BTH pretreatment was lower in ago2 than in wild type, pointing to reduced capacity of ago2 to activate BTH-induced CMV(Y) resistance. A role of AGO2 in pathogen-induced SAR is suggested by the enhanced activation of AGO2 after infiltrating systemic leaves of plants expressing a localized hypersensitive response upon CMV(Y) infection. In addition, local inoculation of SAR-inducing Pseudomonas syringae pv. maculicola causes systemic priming for enhanced AGO2 expression. Together our results indicate that defence priming targets the AGO2 component of RNA silencing whose enhanced expression is likely to contribute to SAR.
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Affiliation(s)
- Sugihiro Ando
- Graduate School of Agricultural ScienceTohoku UniversitySendaiJapan
- Department of Plant PhysiologyAachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
| | - Michal Jaskiewicz
- Department of Plant PhysiologyAachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
| | - Sei Mochizuki
- Graduate School of Agricultural ScienceTohoku UniversitySendaiJapan
| | - Saeko Koseki
- Graduate School of Agricultural ScienceTohoku UniversitySendaiJapan
| | - Shuhei Miyashita
- Graduate School of Agricultural ScienceTohoku UniversitySendaiJapan
| | - Hideki Takahashi
- Graduate School of Agricultural ScienceTohoku UniversitySendaiJapan
| | - Uwe Conrath
- Department of Plant PhysiologyAachen Biology and BiotechnologyRWTH Aachen UniversityAachenGermany
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62
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Jin Y, Zhao JH, Guo HS. Recent advances in understanding plant antiviral RNAi and viral suppressors of RNAi. Curr Opin Virol 2020; 46:65-72. [PMID: 33360834 DOI: 10.1016/j.coviro.2020.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 10/22/2022]
Abstract
Molecular plant-virus interactions provide an excellent model to understanding host antiviral immunity and viral counter-defense mechanisms. The primary antiviral defense is triggered inside the infected plant cell by virus-derived small-interfering RNAs, which guide homology-dependent RNA interference (RNAi) and/or RNA-directed DNA methylation (RdDM) to target RNA and DNA viruses. In counter-defense, plant viruses have independently evolved viral suppressors of RNAi (VSRs) to specifically antagonize antiviral RNAi. Recent studies have shown that plant antiviral responses are regulated by endogenous small silencing RNAs, RNA decay and autophagy and that some known VSRs of plant RNA and DNA viruses also target these newly recognized defense responses to promote infection. This review focuses on these recent advances that have revealed multilayered regulation of plant-virus interactions.
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Affiliation(s)
- Yun Jin
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing 100049, China.
| | - Jian-Hua Zhao
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Hui-Shan Guo
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, CAS Center for Excellence in Biotic Interactions, University of the Chinese Academy of Sciences, Beijing 100049, China
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63
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Watt LG, Crawshaw S, Rhee SJ, Murphy AM, Canto T, Carr JP. The cucumber mosaic virus 1a protein regulates interactions between the 2b protein and ARGONAUTE 1 while maintaining the silencing suppressor activity of the 2b protein. PLoS Pathog 2020; 16:e1009125. [PMID: 33270799 PMCID: PMC7738167 DOI: 10.1371/journal.ppat.1009125] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 12/15/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022] Open
Abstract
The cucumber mosaic virus (CMV) 2b viral suppressor of RNA silencing (VSR) is a potent counter-defense and pathogenicity factor that inhibits antiviral silencing by titration of short double-stranded RNAs. It also disrupts microRNA-mediated regulation of host gene expression by binding ARGONAUTE 1 (AGO1). But in Arabidopsis thaliana complete inhibition of AGO1 is counterproductive to CMV since this triggers another layer of antiviral silencing mediated by AGO2, de-represses strong resistance against aphids (the insect vectors of CMV), and exacerbates symptoms. Using confocal laser scanning microscopy, bimolecular fluorescence complementation, and co-immunoprecipitation assays we found that the CMV 1a protein, a component of the viral replicase complex, regulates the 2b-AGO1 interaction. By binding 2b protein molecules and sequestering them in P-bodies, the 1a protein limits the proportion of 2b protein molecules available to bind AGO1, which ameliorates 2b-induced disease symptoms, and moderates induction of resistance to CMV and to its aphid vector. However, the 1a protein-2b protein interaction does not inhibit the ability of the 2b protein to inhibit silencing of reporter gene expression in agroinfiltration assays. The interaction between the CMV 1a and 2b proteins represents a novel regulatory system in which specific functions of a VSR are selectively modulated by another viral protein. The finding also provides a mechanism that explains how CMV, and possibly other viruses, modulates symptom induction and manipulates host-vector interactions.
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Affiliation(s)
- Lewis G. Watt
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Sam Crawshaw
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Sun-Ju Rhee
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Alex M. Murphy
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Tomás Canto
- Department of Microbial and Plant Biotechnology, Center for Biological Research, Madrid, Spain
| | - John P. Carr
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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64
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Wu H, Qu X, Dong Z, Luo L, Shao C, Forner J, Lohmann JU, Su M, Xu M, Liu X, Zhu L, Zeng J, Liu S, Tian Z, Zhao Z. WUSCHEL triggers innate antiviral immunity in plant stem cells. Science 2020; 370:227-231. [PMID: 33033220 DOI: 10.1126/science.abb7360] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 07/28/2020] [Accepted: 08/21/2020] [Indexed: 02/05/2023]
Abstract
Stem cells in plants constantly supply daughter cells to form new organs and are expected to safeguard the integrity of the cells from biological invasion. Here, we show how stem cells of the Arabidopsis shoot apical meristem and their nascent daughter cells suppress infection by cucumber mosaic virus (CMV). The stem cell regulator WUSCHEL responds to CMV infection and represses virus accumulation in the meristem central and peripheral zones. WUSCHEL inhibits viral protein synthesis by repressing the expression of plant S-adenosyl-l-methionine-dependent methyltransferases, which are involved in ribosomal RNA processing and ribosome stability. Our results reveal a conserved strategy in plants to protect stem cells against viral intrusion and provide a molecular basis for WUSCHEL-mediated broad-spectrum innate antiviral immunity in plants.
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Affiliation(s)
- Haijun Wu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Xiaoya Qu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Zhicheng Dong
- School of Life Sciences, Guangzhou University, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Linjie Luo
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Chen Shao
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Joachim Forner
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg D-69120, Germany
| | - Jan U Lohmann
- Department of Stem Cell Biology, Centre for Organismal Studies, Heidelberg University, Heidelberg D-69120, Germany
| | - Meng Su
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Mengchu Xu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Xiaobin Liu
- School of Life Sciences, Guangzhou University, Guangzhou Higher Education Mega Center, Guangzhou 510006, China
| | - Lei Zhu
- State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jian Zeng
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Sumei Liu
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Zhaoxia Tian
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
| | - Zhong Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Molecular Plant Sciences, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
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65
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Characterization of cucumber mosaic virus (CMV) subgroup IB infecting chilli in Tamil Nadu, India. 3 Biotech 2020; 10:500. [PMID: 33163319 DOI: 10.1007/s13205-020-02492-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/15/2020] [Indexed: 10/23/2022] Open
Abstract
CMV (cucumber mosaic virus) is the most primitive virus infecting chilli (Capsicum annuum. L). The mosaic incidence with leaf filiformity, mosaic mottling and stunted growth was observed in major chilli growing regions of Tamil Nadu. CMV sap was inoculated on chilli, cowpea, bitter gourd, bottle gourd, ridge gourd, banana, cucumber, Nicotiana and Chenopodium plants. Host range studies revealed that CMV produced localized infection on Nicotiana and systemic symptoms on most of the test plants. The occurrence of CMV was confirmed through DAC-ELISA and RT-PCR analysis. Host plant samples tested with DAC-ELISA showed strong reaction with 1.7 optical density. For molecular characterization, total RNA isolated from infected plants used in RT-PCR with CMV specific primers. The specific amplicons were cloned and sequenced. The complete genome sequencing depicts CMV-RNA1 consist of 3339 nucleotides (nt), RNA2 and RNA3 with 3052nt and 2027nt respectively. Phylogenetic and nucleotide sequence analysis showed TN CMV isolates closely associated with subgroup IB rather than subgroup IA and II. Comparative sequence analysis indicates replicase protein to be more variable among five genes. CP sequence analysis showed 97-98 per cent identity with subgroup IB strains, 92-93 per cent identity with subgroup IA strains and 81-82 per cent identity with subgroup II strains. CMV-RNA3 was predicted to have recombination with Indian black pepper isolate (KU947031) between 165-505nt and Egyptian tomato isolate (KX014666) between 165-506nt positions.
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66
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Gao F, Zhao S, Men S, Kang Z, Hong J, Wei C, Hong W, Li Y. A non-structural protein encoded by Rice Dwarf Virus targets to the nucleus and chloroplast and inhibits local RNA silencing. SCIENCE CHINA. LIFE SCIENCES 2020; 63:1703-1713. [PMID: 32303960 DOI: 10.1007/s11427-019-1648-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/13/2020] [Indexed: 02/08/2023]
Abstract
RNA silencing is a potent antiviral mechanism in plants and animals. As a counter-defense, many viruses studied to date encode one or more viral suppressors of RNA silencing (VSR). In the latter case, how different VSRs encoded by a virus function in silencing remains to be fully understood. We previously showed that the nonstructural protein Pns10 of a Phytoreovirus, Rice dwarf virus (RDV), functions as a VSR. Here we present evidence that another nonstructural protein, Pns11, also functions as a VSR. While Pns10 was localized in the cytoplasm, Pns11 was localized both in the nucleus and chloroplasts. Pns11 has two bipartite nuclear localization signals (NLSs), which were required for nuclear as well as chloroplastic localization. The NLSs were also required for the silencing activities of Pns11. This is the first report that multiple VSRs encoded by a virus are localized in different subcellular compartments, and that a viral protein can be targeted to both the nucleus and chloroplast. These findings may have broad significance in studying the subcellular targeting of VSRs and other viral proteins in viral-host interactions.
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Affiliation(s)
- Feng Gao
- The State Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, 20742, USA
| | - Shanshan Zhao
- The State Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
- College of Plant Protection, Fujian Agriculture & Forestry University, Fuzhou, 350002, China
| | - Shuzhen Men
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Zhensheng Kang
- Department of Plant Protection, Northwestern Agriculture and Forestry University, Yangling, 712100, China
| | - Jian Hong
- College of Agriculture, Zhejiang University, Hangzhou, 310029, China
| | - Chunhong Wei
- The State Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
| | - Wei Hong
- The State Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China.
- The First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, 310006, China.
| | - Yi Li
- The State Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China.
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67
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Pollari M, De S, Wang A, Mäkinen K. The potyviral silencing suppressor HCPro recruits and employs host ARGONAUTE1 in pro-viral functions. PLoS Pathog 2020; 16:e1008965. [PMID: 33031436 PMCID: PMC7575100 DOI: 10.1371/journal.ppat.1008965] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/20/2020] [Accepted: 09/04/2020] [Indexed: 11/19/2022] Open
Abstract
In this study, we demonstrate a novel pro-viral role for the Nicotiana benthamiana ARGONAUTE 1 (AGO1) in potyvirus infection. AGO1 strongly enhanced potato virus A (PVA) particle production and benefited the infection when supplied in excess. We subsequently identified the potyviral silencing suppressor, helper-component protease (HCPro), as the recruiter of host AGO1. After the identification of a conserved AGO1-binding GW/WG motif in potyviral HCPros, we used site-directed mutagenesis to introduce a tryptophan-to-alanine change into the HCPro (HCProAG) of PVA (PVAAG) and turnip mosaic virus (TuMVAG). AGO1 co-localization and co-immunoprecipitation with PVA HCPro was significantly reduced by the mutation suggesting the interaction was compromised. Although the mutation did not interfere with HCPro's complementation or silencing suppression capacity, it nevertheless impaired virus particle accumulation and the systemic spread of both PVA and TuMV. Furthermore, we found that the HCPro-AGO1 interaction was important for AGO1's association with the PVA coat protein. The coat protein was also more stable in wild type PVA infection than in PVAAG infection. Based on these findings we suggest that potyviral HCPro recruits host AGO1 through its WG motif and engages AGO1 in the production of stable virus particles, which are required for an efficient systemic infection.
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Affiliation(s)
- Maija Pollari
- University of Helsinki, Department of Microbiology, Viikki Plant Science Center, Helsinki, Finland
| | - Swarnalok De
- University of Helsinki, Department of Microbiology, Viikki Plant Science Center, Helsinki, Finland
| | - Aiming Wang
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Kristiina Mäkinen
- University of Helsinki, Department of Microbiology, Viikki Plant Science Center, Helsinki, Finland
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68
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Zhang CW, Liu Q, Zeng Q, Huang WT, Wang Q, Cheng YQ. p24 G1 Encoded by Grapevine Leafroll-Associated Virus 1 Suppresses RNA Silencing and Elicits Hypersensitive Response-Like Necrosis in Nicotiana Species. Viruses 2020; 12:E1111. [PMID: 33007975 PMCID: PMC7601950 DOI: 10.3390/v12101111] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/19/2020] [Accepted: 09/29/2020] [Indexed: 01/21/2023] Open
Abstract
Grapevine leafroll-associated virus 1 (GLRaV-1) is a major pathogen associated with grapevine leafroll disease. However, the molecular mechanisms underlying GLRaV-1 interactions with plant cells are unclear. Using Agrobacterium infiltration-mediated RNA-silencing assays, we demonstrated that GLRaV-1 p24 protein (p24G1) acts as an RNA-silencing suppressor (RSS), inhibiting local and systemic RNA silencing. Electrophoretic mobility shift assays showed that p24G1 binds double-stranded 21-nucleotide small interfering RNA (siRNA), and that siRNA binding is required but not sufficient for its RSS activity. p24G1 localizes in the nucleus and can self-interact through its amino acid 10 to 210 region. Dimerization is needed for p24G1 interaction with importin α1 before moving to the nucleus, but is not required for its siRNA binding and RSS activity. Expression of p24G1 from a binary pGD vector or potato virus X-based vector elicited a strong hypersensitive response in Nicotiana species, indicating that p24G1 may be a factor in pathogenesis. Furthermore, p24G1 function in pathogenesis required its RSS activity, dimerization and nuclear localization. In addition, the region of amino acids 122-139 played a crucial role in the nuclear import, siRNA binding, silencing suppression and pathogenic activity of p24G1. These results contribute to our understanding of the molecular mechanisms underlying GLRaV-1 infection.
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Affiliation(s)
- Chen-Wei Zhang
- Department of Pomology, China Agricultural University, Beijing 100193, China; (C.-W.Z.); (Q.L.); (Q.Z.); (W.-T.H.)
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China
| | - Qing Liu
- Department of Pomology, China Agricultural University, Beijing 100193, China; (C.-W.Z.); (Q.L.); (Q.Z.); (W.-T.H.)
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China
| | - Qi Zeng
- Department of Pomology, China Agricultural University, Beijing 100193, China; (C.-W.Z.); (Q.L.); (Q.Z.); (W.-T.H.)
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China
| | - Wen-Ting Huang
- Department of Pomology, China Agricultural University, Beijing 100193, China; (C.-W.Z.); (Q.L.); (Q.Z.); (W.-T.H.)
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China
| | - Qi Wang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China;
| | - Yu-Qin Cheng
- Department of Pomology, China Agricultural University, Beijing 100193, China; (C.-W.Z.); (Q.L.); (Q.Z.); (W.-T.H.)
- Key Laboratory of Viticulture and Enology, Ministry of Agriculture, Beijing 100083, China
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69
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Sun Q, Zhuo T, Zhao T, Zhou C, Li Y, Wang Y, Li D, Yu J, Han C. Functional Characterization of RNA Silencing Suppressor P0 from Pea Mild Chlorosis Virus. Int J Mol Sci 2020; 21:E7136. [PMID: 32992609 PMCID: PMC7582759 DOI: 10.3390/ijms21197136] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/20/2020] [Accepted: 09/23/2020] [Indexed: 01/22/2023] Open
Abstract
To counteract host antiviral RNA silencing, plant viruses encode numerous viral suppressors of RNA silencing (VSRs). P0 proteins have been identified as VSRs in many poleroviruses. However, their suppressor function has not been fully characterized. Here, we investigated the function of P0 from pea mild chlorosis virus (PMCV) in the suppression of local and systemic RNA silencing via green fluorescent protein (GFP) co-infiltration assays in wild-type and GFP-transgenic Nicotiana benthamiana (line 16c). Amino acid deletion analysis showed that N-terminal residues Asn 2 and Val 3, but not the C-terminus residues from 230-270 aa, were necessary for PMCV P0 (P0PM) VSR activity. P0PM acted as an F-box protein, and triple LPP mutation (62LPxx79P) at the F-box-like motif abolished its VSR activity. In addition, P0PM failed to interact with S-phase kinase-associated protein 1 (SKP1), which was consistent with previous findings of P0 from potato leafroll virus. These data further support the notion that VSR activity of P0 is independent of P0-SKP1 interaction. Furthermore, we examined the effect of P0PM on ARGONAUTE1 (AGO1) protein stability, and co-expression analysis showed that P0PM triggered AGO1 degradation. Taken together, our findings suggest that P0PM promotes degradation of AGO1 to suppress RNA silencing independent of SKP1 interaction.
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Affiliation(s)
- Qian Sun
- College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China;
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Tao Zhuo
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Tianyu Zhao
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Cuiji Zhou
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Yuanyuan Li
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Ying Wang
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Dawei Li
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Jialin Yu
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
| | - Chenggui Han
- State Key Laboratory for Agro-Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China; (T.Z.); (T.Z.); (C.Z.); (Y.L.); (Y.W.); (D.L.); (J.Y.)
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70
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Khaing YY, Kobayashi Y, Takeshita M. The C-terminal region of the 2a protein and 2b protein of cucumber mosaic virus are involved in the induction of shoestring-like leaf blade in tomato. Virus Res 2020; 289:198172. [PMID: 32980403 DOI: 10.1016/j.virusres.2020.198172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 11/28/2022]
Abstract
Cucumber mosaic virus (CMV) has numerous strains with distinct pathological properties in nature. In this study, we focused on the distinct host-specificity of two isolates of CMV regarding induction of the shoestring-like leaf blade (SLB) in tomato (Solanum lycopersicum cv. Sekaiichi). During the initial infection stage, plants inoculated with CMV-D8 and CMV-Y developed green/yellow systemic mosaic and stunting. Late in infection, CMV-D8 caused severe systemic symptoms with SLB on the newly emerged leaves, whereas CMY-Y caused severe yellow mosaic with stunting. Accumulation of viral RNA of CMV-D8 during initial infection was higher than for CMV-Y, but their levels did not differ significantly at 5 weeks post inoculation. Pseudorecombination and recombination analyses between CMV-D8 and CMV-Y genomic RNAs showed that recombinant that contained the C-terminal region of 2a and the entire 2b protein of CMV-D8 (D2a-C/D2b) induced SLB. Changing isoleucine to valine at position 830 in the 2a ORF played an important role in formation of chronic SLB. We further elucidated that infection with CMV-D8 or the recombinant Y1Y2(D2a-C/D2b)D3, but not with CMV-Y, upregulated miRNAs and transcript levels of AGO1, which is involved in RNA silencing, and of HD-ZIP, TCP4, and PHAN, which are essential for leaf morphogenesis. The present results first demonstrated that the cooperative function of D2a-C/D2b is involved indispensably in SLB formation. In addition, we suggest that D2a-C/D2b region interferes with the miRNA pathway that is associated with RNA silencing and leaf morphogenesis, leading to the enhanced virulence of CMV-D8.
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Affiliation(s)
- Yu Yu Khaing
- Laboratory of Plant Pathology, Faculty of Agriculture, Department of Agricultural and Environmental Sciences, University of Miyazaki, Gakuenkibanadainishi 1-1, Miyazaki 889-2192, Japan
| | - Yudai Kobayashi
- Laboratory of Plant Pathology, Faculty of Agriculture, Department of Agricultural and Environmental Sciences, University of Miyazaki, Gakuenkibanadainishi 1-1, Miyazaki 889-2192, Japan
| | - Minoru Takeshita
- Laboratory of Plant Pathology, Faculty of Agriculture, Department of Agricultural and Environmental Sciences, University of Miyazaki, Gakuenkibanadainishi 1-1, Miyazaki 889-2192, Japan.
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71
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Spinler JK, Oezguen N, Runge JK, Luna RA, Karri V, Yang J, Hirschi KD. Dietary impact of a plant-derived microRNA on the gut microbiome. ACTA ACUST UNITED AC 2020; 2. [PMID: 33542959 PMCID: PMC7856875 DOI: 10.1186/s41544-020-00053-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background: Global estimations of 4 billion people living on plant-based diets signify tremendous diversity in plant consumption and their assorted miRNAs, which presents a challenging model to experimentally address how plant-based miRNAs impact the microbiome. Here we establish baseline gut microbiome composition for a mouse model deficient in the specific mammalian miR-146a shown to alter gut microbiomes. We then asses the effect on the gut microbiome when miR-146a-deficient mice are fed a transgenic plant-based diet expressing the murine-derived miR-146a. Mice deficient in miR-146a were maintained either on a baseline diet until 7 weeks of age (day 0) and then fed either vector or miR-146a-expressing plant-based diets for 21 days. The gut microbiomes of mice were examined by comparing the V4 region of 16S rRNA gene sequences of DNA isolated from fecal samples at days 0 (baseline diet) and 21 (vector or miR-146a expressing plant-based diets). Results: Beta-diversity analysis demonstrated that the transition from baseline chow to a plant-based diet resulted in significant longitudinal shifts in microbial community structure attributable to increased fiber intake. Bipartite network analysis suggests that miR-146a-deficient mice fed a plant diet rich in miR-146a have a microbiome population modestly different than mice fed an isogenic control plant diet deficient in miR-146a. Conclusion: A mouse diet composed of a transgenic plant expressing a mouse miR-146a may fine tune microbial communities but does not appear to have global effects on microbiome structure and composition.
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Affiliation(s)
- Jennifer K Spinler
- Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, 1102 Bates Ave, Houston, TX 77030, USA
| | - Numan Oezguen
- Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, 1102 Bates Ave, Houston, TX 77030, USA
| | - Jessica K Runge
- Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, 1102 Bates Ave, Houston, TX 77030, USA
| | - Ruth Ann Luna
- Texas Children's Microbiome Center, Department of Pathology, Texas Children's Hospital, Houston, TX, USA.,Department of Pathology & Immunology, Baylor College of Medicine, One Baylor Plaza, 1102 Bates Ave, Houston, TX 77030, USA
| | | | - Jian Yang
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, 1100 Bates Ave, Houston, TX 77030, USA
| | - Kendal D Hirschi
- Pediatrics-Nutrition, Children's Nutrition Research, Baylor College of Medicine, 1100 Bates Ave, Houston, TX 77030, USA
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Hu SF, Wei WL, Hong SF, Fang RY, Wu HY, Lin PC, Sanobar N, Wang HP, Sulistio M, Wu CT, Lo HF, Lin SS. Investigation of the effects of P1 on HC-pro-mediated gene silencing suppression through genetics and omics approaches. BOTANICAL STUDIES 2020; 61:22. [PMID: 32748085 PMCID: PMC7399735 DOI: 10.1186/s40529-020-00299-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/16/2020] [Indexed: 05/15/2023]
Abstract
BACKGROUND Posttranscriptional gene silencing (PTGS) is one of the most important mechanisms for plants during viral infection. However, viruses have also developed viral suppressors to negatively control PTGS by inhibiting microRNA (miRNA) and short-interfering RNA (siRNA) regulation in plants. The first identified viral suppressor, P1/HC-Pro, is a fusion protein that was translated from potyviral RNA. Upon infecting plants, the P1 protein itself is released from HC-Pro by the self-cleaving activity of P1. P1 has an unknown function in enhancing HC-Pro-mediated PTGS suppression. We performed proteomics to identify P1-interacting proteins. We also performed transcriptomics that were generated from Col-0 and various P1/HC-Pro-related transgenic plants to identify novel genes. The results showed several novel genes were identified through the comparative network analysis that might be involved in P1/HC-Pro-mediated PTGS suppression. RESULTS First, we demonstrated that P1 enhances HC-Pro function and that the mechanism might work through P1 binding to VERNALIZATION INDEPENDENCE 3/SUPERKILLER 8 (VIP3/SKI8), a subunit of the exosome, to interfere with the 5'-fragment of the PTGS-cleaved RNA degradation product. Second, the AGO1 was specifically posttranslationally degraded in transgenic Arabidopsis expressing P1/HC-Pro of turnip mosaic virus (TuMV) (P1/HCTu plant). Third, the comparative network highlighted potentially critical genes in PTGS, including miRNA targets, calcium signaling, hormone (JA, ET, and ABA) signaling, and defense response. CONCLUSION Through these genetic and omics approaches, we revealed an overall perspective to identify many critical genes involved in PTGS. These new findings significantly impact in our understanding of P1/HC-Pro-mediated PTGS suppression.
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Affiliation(s)
- Sin-Fen Hu
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Wei-Lun Wei
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Syuan-Fei Hong
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Ru-Ying Fang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Hsin-Yi Wu
- Instrumentation Center, National Taiwan University, Taipei, 106, Taiwan
| | - Pin-Chun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Neda Sanobar
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
| | - Hsin-Ping Wang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Margo Sulistio
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Chun-Ta Wu
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Hsiao-Feng Lo
- Department of Horticulture and Landscape Architecture, National Taiwan University, Taipei, 106, Taiwan
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan.
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan.
- Center of Biotechnology, National Taiwan University, Taipei, 106, Taiwan.
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73
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Li Y, Sun D, Ma Z, Yamaguchi K, Wang L, Zhong S, Yan X, Shang B, Nagashima Y, Koiwa H, Han J, Xie Q, Zhou M, Wang Z, Zhang X. Degradation of SERRATE via ubiquitin-independent 20S proteasome to survey RNA metabolism. NATURE PLANTS 2020; 6:970-982. [PMID: 32690892 PMCID: PMC7426255 DOI: 10.1038/s41477-020-0721-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 04/16/2020] [Indexed: 05/18/2023]
Abstract
SERRATE (SE) is a key factor in RNA metabolism. Here, we report that SE binds 20S core proteasome α subunit G1 (PAG1) among other components and is accumulated in their mutants. Purified PAG1-containing 20S proteasome degrades recombinant SE via an ATP- and ubiquitin-independent manner in vitro. Nevertheless, PAG1 is a positive regulator for SE in vivo, as pag1 shows comparable molecular and/or developmental defects relative to se. Furthermore, SE is poorly assembled into macromolecular complexes, exemplified by the microprocessor in pag1 compared with Col-0. SE overexpression triggered the destruction of both transgenic and endogenous protein, leading to similar phenotypes of se and SE overexpression lines. We therefore propose that PAG1 degrades the intrinsically disordered portion of SE to secure the functionality of folded SE that is assembled and protected in macromolecular complexes. This study provides insight into how the 20S proteasome regulates RNA metabolism through controlling its key factor in eukaryotes.
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Affiliation(s)
- Yanjun Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Di Sun
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Zeyang Ma
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Karissa Yamaguchi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Lin Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Songxiao Zhong
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Xingxing Yan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Baoshuan Shang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Yukihiro Nagashima
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA
| | - Hisashi Koiwa
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA
| | - Jiajia Han
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Yunnan Key Laboratory of Plant Reproductive Adaption and Evolutionary Ecology, Yunnan University, Kunming, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhiye Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China.
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
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74
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Efficient silencing gene construct for resistance to multiple common bean ( Phaseolus vulgaris L.) viruses. 3 Biotech 2020; 10:278. [PMID: 32537378 DOI: 10.1007/s13205-020-02276-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/25/2020] [Indexed: 12/16/2022] Open
Abstract
One promising strategy to engineer plants that are resistant to plant pathogens involves transforming plants with RNA silencing constructs for resistance to multiple pathogens. Garden bean is significantly damaged by bean common mosaic virus (BCMV), bean common mosaic necrosis virus (BCMNV) and cucumber mosaic virus (CMV). In this study, we prepared constructs producing sense, antisense and hairpin RNA (hpRNA) structures to target single as well as multiple viruses. Silencing efficiency of these constructions was analyzed using Agrobacterium (GV3101) transient expression in Nicothinia bethamiana and Phaseolus vulgaris plants. The results showed significantly reduced disease symptoms and virus accumulation in N. bethamiana plants. Generally, the efficiency of the prepared constructs was hairpin, antisense and sense, respectively, and also, there was a significant difference between mono-gene and multiple-gene constructs for reducng virus accumulation and the multiple-gene constructs showed higher effectiveness. Experiments in this study showed that using Agrobacterium harboring binary constructs containing a Caenorhabditis elegans gene, Ced-9, or a plant gene, AtBag-4, anti-apoptosis gene as a mix suspension with an Agrobacterium containing pFGC-BNC.h, a plasmid containing multiple gene fragments consisting of BCMV-CP, BCMNV-HC-Pro and CMV-2b, improved the efficiency of pFGC-BNC.h transformation. We showed reduced virus accumulation in these transgenic bean plans.
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75
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Yang L, Meng D, Wang Y, Wu Y, Lang C, Jin T, Zhou X. The viral suppressor HCPro decreases DNA methylation and activates auxin biosynthesis genes. Virology 2020; 546:133-140. [PMID: 32452413 DOI: 10.1016/j.virol.2020.04.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 01/10/2023]
Abstract
Auxin has profound effects on plant growth and development. In addition to participating in plant growth and development, the auxin signaling pathway is involved in plant defense against pathogens. In this study, we investigated the molecular mechanism by which helper-component protease (HCPro) encoded by the Tobacco vein banding mosaic virus (TVBMV) activates auxin biosynthesis genes (YUCs) and interferes with the auxin signaling pathway. Our results demonstrated that the viral suppressor HCPro decreased the DNA methylation of dispersed repeats (DRs) within the promoters of YUC1, YUC5 and YUC10 and transcriptional activated these YUC genes targeted by RNA-directed DNA methylation (RdDM), leading to an increase in auxin accumulation in plants. Furthermore, we found that the induction of these YUCs by HCPro was attenuated in ros1 mutant plants, suggesting that HCPro-mediated transcriptional activation of the genes was partly dependent on ROS1-mediated DNA demethylation.
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Affiliation(s)
- Liping Yang
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China.
| | - Dawei Meng
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China.
| | - Yue Wang
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China.
| | - Yanju Wu
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China.
| | - Chenjing Lang
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China
| | - Taicheng Jin
- The School of Life Sciences, Jilin Normal University, Siping, 136000, China.
| | - Xiaofu Zhou
- Key Laboratory for Plant Resources Science and Green Production, Jilin Normal University, Siping, 136000, China.
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76
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Huang CH, Foo MH, Raja JAJ, Tan YR, Lin TT, Lin SS, Yeh SD. A Conserved Helix in the C-Terminal Region of Watermelon Silver Mottle Virus Nonstructural Protein S Is Imperative For Protein Stability Affecting Self-Interaction, RNA Silencing Suppression, and Pathogenicity. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:637-652. [PMID: 31935338 DOI: 10.1094/mpmi-10-19-0279-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In orthotospovirus, the nonstructural protein S (NSs) is the RNA-silencing suppressor (RSS) and pathogenicity determinant. Here, we demonstrate that a putative α-helix, designated H8, spanning amino acids 338 to 369 of the C-terminal region of the NSs protein, is crucial for self-interaction of watermelon silver mottle virus NSs protein and that the H8 affects RSS function. Co-immunoprecipitation, yeast two-hybrid, and bimolecular fluorescence complementation analyses revealed that the triple point mutation (TPM) of H8 amino acids Y338A, H350A, and F353A resulted in NSs protein self-interaction dysfunction. Transient expression of H8-deleted (ΔH8) and TPM NSs proteins in Nicotiana benthamiana plants by agroinfitration indicated that these proteins have weaker RSS activity and are far less stable than wild-type (WT) NSs. However, an electrophoretic mobility assay revealed that small interfering RNA (siRNA) binding ability of TPM NSs protein is not compromised. The pathogenicity assay of WT NSs protein expressed by the attenuated turnip mosaic virus vector restored severe symptoms in recombinant-infected N. benthamiana plants but not for ΔH8 or TPM proteins. Taken together, we conclude that the H8 helix in the C-terminal region of NSs protein is crucial for stabilizing NSs protein through self-interaction to maintain normal functions of RSS and pathogenicity, but not for NSs-siRNA binding activity.
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Affiliation(s)
- Chung-Hao Huang
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
- Advanced Plant Biotechnology Center, National Chung Hsing University
| | - Mung-Hsia Foo
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
| | - Joseph A J Raja
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
- Advanced Plant Biotechnology Center, National Chung Hsing University
| | - Yue-Rong Tan
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
| | - Tzu-Tung Lin
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
| | - Shih-Shun Lin
- Advanced Plant Biotechnology Center, National Chung Hsing University
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan, Republic of China
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung Hsing University, Taichung 40227, Taiwan, Republic of China
- Advanced Plant Biotechnology Center, National Chung Hsing University
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77
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Zhang C, Chen D, Yang G, Yu X, Wu J. Rice Stripe Mosaic Virus-Encoded P4 Is a Weak Suppressor of Viral RNA Silencing and Is Required for Disease Symptom Development. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:412-422. [PMID: 31841359 DOI: 10.1094/mpmi-08-19-0239-ia] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Viral suppressors of RNA silencing (VSRs) are a cluster of viral proteins that have evolved to counteract eukaryotic antiviral RNA silencing pathways, thereby contributing to viral pathogenicity. In this study, we revealed that the matrix protein P4 encoded by rice stripe mosaic virus (RSMV), which is an emerging cytoplasmic rhabdovirus, is a weak RNA silencing suppressor. By conducting yeast two-hybrid, bimolecular fluorescence complementation, and subcellular colocalization assays, we proved that P4 interacts with the rice endogenous suppressor of gene silencing 3 (OsSGS3). We also determined that P4 overexpression has no effect on OsSGS3 transcription. However, P4 can promote the degradation of OsSGS3 via ubiquitination and autophagy. Additionally, a potato virus X-based expression system was used to confirm that P4 enhances the development of mosaic symptoms on Nicotiana benthamiana leaves by promoting hydrogen peroxide accumulation but not cell death. To verify whether P4 is a pathogenicity factor in host plants, we generated transgenic P4-overexpressing rice plants that exhibited disease-related developmental defects including decreased plant height and excessive tillering. Our data suggest that RSMV-encoded P4 serves as a weak VSR that inhibits antiviral RNA silencing by targeting OsSGS3.
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Affiliation(s)
- Chao Zhang
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Dong Chen
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Guoyi Yang
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiyuan Yu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianguo Wu
- Vector-borne Virus Research Center, State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Institute of Plant Virology, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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Yan Y, Ham BK, Chong YH, Yeh SD, Lucas WJ. A Plant SMALL RNA-BINDING PROTEIN 1 Family Mediates Cell-to-Cell Trafficking of RNAi Signals. MOLECULAR PLANT 2020; 13:321-335. [PMID: 31812689 DOI: 10.1016/j.molp.2019.12.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/30/2019] [Accepted: 12/02/2019] [Indexed: 05/20/2023]
Abstract
In plants, RNA interference (RNAi) plays a pivotal role in growth and development, and responses to environmental inputs, including pathogen attack. The intercellular and systemic trafficking of small interfering RNA (siRNA)/microRNA (miRNA) is a central component in this regulatory pathway. Currently, little is known with regards to the molecular agents involved in the movement of these si/miRNAs. To address this situation, we employed a biochemical approach to identify and characterize a conserved SMALL RNA-BINDING PROTEIN 1 (SRBP1) family that mediates non-cell-autonomous small RNA (sRNA) trafficking. In Arabidopsis, AtSRBP1 is a glycine-rich (GR) RNA-binding protein, also known as AtGRP7, which we show binds single-stranded siRNA. A viral vector, Zucchini yellow mosaic virus (ZYMV), was employed to functionally characterized the AtSRBP1-4 (AtGRP7/2/4/8) RNA recognition motif and GR domains. Cellular-based studies revealed the GR domain as being necessary and sufficient for SRBP1 cell-to-cell movement. Taken together, our findings provide a foundation for future research into the mechanism and function of mobile sRNA signaling agents in plants.
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Affiliation(s)
- Yan Yan
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Byung-Kook Ham
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA
| | - Yee Hang Chong
- Department of Plant Pathology, National Chung-Hsing University, Taichung
| | - Shyi-Dong Yeh
- Department of Plant Pathology, National Chung-Hsing University, Taichung
| | - William J Lucas
- Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA.
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79
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Mei Y, Ma Z, Wang Y, Zhou X. Geminivirus C4 antagonizes the HIR1-mediated hypersensitive response by inhibiting the HIR1 self-interaction and promoting degradation of the protein. THE NEW PHYTOLOGIST 2020; 225:1311-1326. [PMID: 31537050 DOI: 10.1111/nph.16208] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 09/13/2019] [Indexed: 05/13/2023]
Abstract
Tomato leaf curl Yunnan virus (TLCYnV)-encoded C4 protein induces the upregulation of the hypersensitive induced reaction 1 (HIR1) gene but interferes with the HIR1-mediated hypersensitive response (HR). HIR1 self-interaction is essential for the HIR1-induced HR. TLCYnV C4 impairs the HIR1 self-interaction and concomitantly increases the amount of Leucine-Rich Repeat protein 1 (LRR1), a modulator of HIR1, which binds to HIR1. LRR1 promotes the degradation of HIR1, compromising the HIR1-mediated HR. This study provides new insights into the mechanisms employed by a viral protein to counter host resistance through the cooption of the host regulatory system.
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Affiliation(s)
- Yuzhen Mei
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, 310058, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
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80
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Tian A, Miyashita S, Ando S, Takahashi H. Single Amino Acid Substitutions in the Cucumber Mosaic Virus 1a Protein Induce Necrotic Cell Death in Virus-Inoculated Leaves without Affecting Virus Multiplication. Viruses 2020; 12:v12010091. [PMID: 31941092 PMCID: PMC7019621 DOI: 10.3390/v12010091] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 11/24/2022] Open
Abstract
When Arabidopsis thaliana ecotype Col-0 was inoculated with a series of reassortant viruses created by exchanging viral genomic RNAs between two strains of cucumber mosaic virus (CMV), CMV(Y), and CMV(H), cell death developed in the leaves inoculated with reassortant CMV carrying CMV(H) RNA1 encoding 1a protein, but not in noninoculated upper leaves. In general, cell death in virus-infected plants is a critical event for virus survival because virus multiplication is completely dependent on host cell metabolism. However, interestingly, this observed cell death did not affect either virus multiplication in the inoculated leaves or systemic spread to noninoculated upper leaves. Furthermore, the global gene expression pattern of the reassortant CMV-inoculated leaves undergoing cell death was clearly different from that in hypersensitive response (HR) cell death, which is coupled with resistance to CMV. These results indicated that the observed cell death does not appear to be HR cell death but rather necrotic cell death unrelated to CMV resistance. Interestingly, induction of this necrotic cell death depended on single amino acid substitutions in the N-terminal region surrounding the methyltransferase domain of the 1a protein. Thus, development of necrotic cell death might not be induced by non-specific damage as a result of virus multiplication, but by a virus protein-associated mechanism. The finding of CMV 1a protein-mediated induction of necrotic cell death in A. thaliana, which is not associated with virus resistance and HR cell death, has the potential to provide a new pathosystem to study the role of cell death in virus–host plant interactions.
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81
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Xu M, Mazur MJ, Tao X, Kormelink R. Cellular RNA Hubs: Friends and Foes of Plant Viruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:40-54. [PMID: 31415225 DOI: 10.1094/mpmi-06-19-0161-fi] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
RNA granules are dynamic cellular foci that are widely spread in eukaryotic cells and play essential roles in cell growth and development, and immune and stress responses. Different types of granules can be distinguished, each with a specific function and playing a role in, for example, RNA transcription, modification, processing, decay, translation, and arrest. By means of communication and exchange of (shared) components, they form a large regulatory network in cells. Viruses have been reported to interact with one or more of these either cytoplasmic or nuclear granules, and act either proviral, to enable and support viral infection and facilitate viral movement, or antiviral, protecting or clearing hosts from viral infection. This review describes an overview and recent progress on cytoplasmic and nuclear RNA granules and their interplay with virus infection, first in animal systems and as a prelude to the status and current developments on plant viruses, which have been less well studied on this thus far.
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Affiliation(s)
- Min Xu
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Magdalena J Mazur
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Xiaorong Tao
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Richard Kormelink
- Laboratory of Virology, Department of Plant Sciences, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
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82
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Choi B, Kwon SJ, Kim MH, Choe S, Kwak HR, Kim MK, Jung C, Seo JK. A Plant Virus-Based Vector System for Gene Function Studies in Pepper. PLANT PHYSIOLOGY 2019; 181:867-880. [PMID: 31481630 PMCID: PMC6836849 DOI: 10.1104/pp.19.00836] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 08/22/2019] [Indexed: 05/22/2023]
Abstract
While pepper (Capsicum annuum) is a highly recalcitrant species for genetic transformation studies, plant virus-based vectors can provide alternative and powerful tools for transient regulation and functional analysis of genes of interest in pepper. In this study, we established an effective virus-based vector system applicable for transient gain- and loss-of-function studies in pepper using Broad bean wilt virus2 (BBWV2). We engineered BBWV2 as a dual gene expression vector for simultaneous expression of two recombinant proteins in pepper cells. In addition, we established enhanced and stable expression of recombinant proteins from the BBWV2-based dual vector via coexpression of a heterologous viral suppressor of RNA silencing. We also developed a BBWV2-based virus-induced gene silencing (VIGS) vector, and we successfully silenced the phytoene desaturase gene (PDS) using the BBWV2-based VIGS vector in various pepper cultivars. Additionally, we optimized the BBWV2-based VIGS system in pepper by testing the efficiency of PDS gene silencing under different conditions. This BBWV2-based vector system represents a convenient approach for rapid and simple analysis of gene functions in pepper.
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Affiliation(s)
- Boram Choi
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Sun-Jung Kwon
- Horticultural and Herbal Crop Environment Division, National Institute of Horticultural and Herbal Science, Wanju 55365, Republic of Korea
| | - Myung-Hwi Kim
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Siwon Choe
- Department of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Hae-Ryun Kwak
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Mi-Kyeong Kim
- Crop Protection Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Choonkyun Jung
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
- Department of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
| | - Jang-Kyun Seo
- Institutes of Green Bio Science and Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
- Department of International Agricultural Technology, Seoul National University, Pyeongchang 25354, Republic of Korea
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Kulshreshtha A, Kumar Y, Roshan P, Bhattacharjee B, Mukherjee SK, Hallan V. AC4 protein of tomato leaf curl Palampur virus is an RNA silencing suppressor and a pathogenicity determinant. Microb Pathog 2019; 135:103636. [PMID: 31377236 DOI: 10.1016/j.micpath.2019.103636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 07/17/2019] [Indexed: 01/08/2023]
Abstract
Plants deploy RNA silencing as a natural defence against invading viruses involving sequence-specific degradation of the viral RNAs. As a counter-defence strategy, viruses encode suppressor proteins that simultaneously target different steps of the silencing machinery. Tomato leaf curl Palampur virus (ToLCPalV) is a bipartite begomovirus in Geminiviridae family. It is responsible for significant reduction in the crop yield and quality. DNA-A of the virus encodes for six proteins whereas DNA-B codes for two proteins. In this study, all viral genes were screened for their role in suppression of green fluorescent protein (GFP) silencing in Nicotiana tabacum cv. Xanthi, employing agrobacterium based co-infiltration assay. The assay identified AC4 as a potential suppressor of RNA silencing. In addition, AC4 expression also suppressed virus-induced gene silencing (VIGS) of the phytoene desaturase (PDS) gene in N. benthamiana. Potato virus X (PVX) mediated transient expression of the AC4 in N. benthamiana showed enhanced symptoms that include downward leaf curling, leaf puckering and tissue necrosis. Further, N. benthamiana lines stably expressing AC4 showed severe developmental abnormalities. Mutational analysis suggested that glycine at 2nd position is essential for AC4 pathogenicity. Collectively, these findings demonstrate the role of ToLCPalV AC4 in viral pathogenesis, disease establishment and suppression of gene silencing.
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Affiliation(s)
- Aditya Kulshreshtha
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, 176061, India; Plant Virus Lab, Biotechnology Division, CSIR-IHBT, Palampur, Himachal Pradesh, 176061, India
| | - Yogesh Kumar
- Department of Biotechnology, DAV University, Jalandhar, 144012, Punjab, India
| | - Poonam Roshan
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, 176061, India; Plant Virus Lab, Biotechnology Division, CSIR-IHBT, Palampur, Himachal Pradesh, 176061, India
| | - Bipasha Bhattacharjee
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, 176061, India; Plant Virus Lab, Biotechnology Division, CSIR-IHBT, Palampur, Himachal Pradesh, 176061, India
| | - Sunil Kumar Mukherjee
- Division of Plant Pathology, India Agricultural Research Institute, Pusa, New Delhi, 110012, India
| | - Vipin Hallan
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Institute of Himalayan Bioresource Technology, Palampur, Himachal Pradesh, 176061, India; Plant Virus Lab, Biotechnology Division, CSIR-IHBT, Palampur, Himachal Pradesh, 176061, India.
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84
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He L, Wang Q, Gu Z, Liao Q, Palukaitis P, Du Z. A conserved RNA structure is essential for a satellite RNA-mediated inhibition of helper virus accumulation. Nucleic Acids Res 2019; 47:8255-8271. [PMID: 31269212 PMCID: PMC6735963 DOI: 10.1093/nar/gkz564] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/30/2019] [Accepted: 06/20/2019] [Indexed: 12/15/2022] Open
Abstract
As a class of parasitic, non-coding RNAs, satellite RNAs (satRNAs) have to compete with their helper virus for limited amounts of viral and/or host resources for efficient replication, by which they usually reduce viral accumulation and symptom expression. Here, we report a cucumber mosaic virus (CMV)-associated satRNA (sat-T1) that ameliorated CMV-induced symptoms, accompanied with a significant reduction in the accumulation of viral genomic RNAs 1 and 2, which encode components of the viral replicase. Intrans replication assays suggest that the reduced accumulation is the outcome of replication competition. The structural basis of sat-T1 responsible for the inhibition of viral RNA accumulation was determined to be a three-way branched secondary structure that contains two biologically important hairpins. One is indispensable for the helper virus inhibition, and the other engages in formation of a tertiary pseudoknot structure that is essential for sat-T1 survival. The secondary structure containing the pseudoknot is the first RNA element with a biological phenotype experimentally identified in CMV satRNAs, and it is structurally conserved in most CMV satRNAs. Thus, this may be a generic method for CMV satRNAs to inhibit the accumulation of the helper virus via the newly-identified RNA structure.
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Affiliation(s)
- Lu He
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Qian Wang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Zhouhang Gu
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Qiansheng Liao
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
| | - Peter Palukaitis
- Department of Horticultural Sciences, Seoul Women's University, Nowon-gu, Seoul 01797, Republic of Korea
| | - Zhiyou Du
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China
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85
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Roles of Small RNAs in Virus-Plant Interactions. Viruses 2019; 11:v11090827. [PMID: 31491987 PMCID: PMC6783996 DOI: 10.3390/v11090827] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/06/2023] Open
Abstract
Small RNAs (sRNAs), including microRNAs (miRNAs) and short interfering RNAs (siRNAs), are non-coding but powerful RNA molecules of 20–30 nucleotides in length. sRNAs play crucial regulatory roles in diverse plant biological processes. Recently, many studies on sRNAs have been reported. We summarize new findings of sRNAs in virus-plant interactions to accelerate the function analysis of sRNAs. The main content of this review article includes three parts: virus-responsive sRNAs, function analysis of sRNAs in virus pathogenicity or host resistance, and some sRNAs-mediated underlying mechanisms in virus-plant interactions. New findings of sRNAs deepen our understanding about sRNAs’ roles, which might contribute to the design of novel control measures against plant viruses.
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86
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Manavella PA, Yang SW, Palatnik J. Keep calm and carry on: miRNA biogenesis under stress. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:832-843. [PMID: 31025462 DOI: 10.1111/tpj.14369] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/09/2019] [Accepted: 04/23/2019] [Indexed: 05/20/2023]
Abstract
MicroRNAs (miRNAs) are major post-transcriptional regulators of gene expression. Their biogenesis relies on the cleavage of longer precursors by a nuclear localized processing machinery. The evolutionary preference of plant miRNAs to silence transcription factors turned these small molecules into key actors during growth and adaptive responses. Furthermore, during their life cycle plants are subject to changes in the environmental conditions surrounding them. In order to face these changes, plants display unique adaptive capacities based on an enormous developmental plasticity, where miRNAs play central roles. Many individual miRNAs have been shown to modulate the plant response to different environmental cues and stresses. In the last few years, increasing evidence has shown that not only individual genes encoding miRNAs but also the miRNA pathway as a whole is subject to regulation in response to external stimulus. In this review, we discuss the current knowledge about the miRNA pathway. We dissect the pathway to analyze the events leading to the generation of these small RNAs and emphasize the regulation of core components of the miRNA biogenesis machinery.
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Affiliation(s)
- Pablo A Manavella
- Instituto de Agrobiotecnología del Litoral (IAL, CONICET-UNL-FBCB), Santa Fe, 3000, Argentina
| | - Seong W Yang
- Department of Systems Biology, Institute of Life Science and Biotechnology, Yonsei University, Seoul, Korea
| | - Javier Palatnik
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, 2000, Argentina
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87
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Tzean Y, Lee MC, Jan HH, Chiu YS, Tu TC, Hou BH, Chen HM, Chou CN, Yeh HH. Cucumber mosaic virus-induced gene silencing in banana. Sci Rep 2019; 9:11553. [PMID: 31399618 PMCID: PMC6689018 DOI: 10.1038/s41598-019-47962-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/25/2019] [Indexed: 11/17/2022] Open
Abstract
Banana (Musa spp.) is one of the world's most important staple and cash crops. Despite accumulating genetic and transcriptomic data, low transformation efficiency in agronomically important Musa spp. render translational researches in banana difficult by using conventional knockout approaches. To develop tools for translational research in bananas, we developed a virus induced-gene silencing (VIGS) system based on a banana-infecting cucumber mosaic virus (CMV) isolate, CMV 20. CMV 20 genomic RNA 1, 2, and 3, were separately cloned in Agrobacterium pJL89 binary vectors, and a cloning site was introduced on RNA 2 immediately after the 2a open reading frame to insert the gene targeted for silencing. An efficient Agrobacterium inoculation method was developed for banana, which enabled the CMV 20 VIGS vector infection rate to reach 95% in our experiments. CMV 20-based silencing of Musa acuminata cv. Cavendish (AAA group) glutamate 1-semialdehyde aminotransferase (MaGSA) produced a typical chlorotic phenotype and silencing of M. acuminata phytoene desaturase (MaPDS) produced a photobleachnig phenotype. We show this approach efficiently reduced GSA and PDS transcripts to 10% and 18% of the control, respectively. The high infection rate and extended silencing of this VIGS system will provide an invaluable tool to accelerate functional genomic studies in banana.
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Affiliation(s)
- Yuh Tzean
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Ming-Chi Lee
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Hsiao-Hsuan Jan
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
- Department of Plant Pathology and Microbiology, National Taiwan University, No. 1, Section 4, Roosevelt Road, Da'an District, Taipei, 10617, Taiwan
| | - Yi-Shu Chiu
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Tsui-Chin Tu
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Bo-Han Hou
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Ho-Ming Chen
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan
| | - Chun-Nan Chou
- Department of Plant Pathology and Microbiology, National Taiwan University, No. 1, Section 4, Roosevelt Road, Da'an District, Taipei, 10617, Taiwan
| | - Hsin-Hung Yeh
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei, 11529, Taiwan.
- Department of Plant Pathology and Microbiology, National Taiwan University, No. 1, Section 4, Roosevelt Road, Da'an District, Taipei, 10617, Taiwan.
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88
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Zheng X, Fahlgren N, Abbasi A, Berry JC, Carrington JC. Antiviral ARGONAUTEs Against Turnip Crinkle Virus Revealed by Image-Based Trait Analysis. PLANT PHYSIOLOGY 2019; 180:1418-1435. [PMID: 31043494 PMCID: PMC6752898 DOI: 10.1104/pp.19.00121] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/21/2019] [Indexed: 05/18/2023]
Abstract
RNA-based silencing functions as an important antiviral immunity mechanism in plants. Plant viruses evolved to encode viral suppressors of RNA silencing (VSRs) that interfere with the function of key components in the silencing pathway. As effectors in the RNA silencing pathway, ARGONAUTE (AGO) proteins are targeted by some VSRs, such as that encoded by Turnip crinkle virus (TCV). A VSR-deficient TCV mutant was used to identify AGO proteins with antiviral activities during infection. A quantitative phenotyping protocol using an image-based color trait analysis pipeline on the PlantCV platform, with temporal red, green, and blue imaging and a computational segmentation algorithm, was used to measure plant disease after TCV inoculation. This process captured and analyzed growth and leaf color of Arabidopsis (Arabidopsis thaliana) plants in response to virus infection over time. By combining this quantitative phenotypic data with molecular assays to detect local and systemic virus accumulation, AGO2, AGO3, and AGO7 were shown to play antiviral roles during TCV infection. In leaves, AGO2 and AGO7 functioned as prominent nonadditive, anti-TCV effectors, whereas AGO3 played a minor role. Other AGOs were required to protect inflorescence tissues against TCV. Overall, these results indicate that distinct AGO proteins have specialized, modular roles in antiviral defense across different tissues, and demonstrate the effectiveness of image-based phenotyping to quantify disease progression.
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Affiliation(s)
- Xingguo Zheng
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Noah Fahlgren
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Arash Abbasi
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Jeffrey C Berry
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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89
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Bhattacharjee S, Roche B, Martienssen RA. RNA-induced initiation of transcriptional silencing (RITS) complex structure and function. RNA Biol 2019; 16:1133-1146. [PMID: 31213126 DOI: 10.1080/15476286.2019.1621624] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Heterochromatic regions of the genome are epigenetically regulated to maintain a heritable '"silent state"'. In fission yeast and other organisms, epigenetic silencing is guided by nascent transcripts, which are targeted by the RNA interference pathway. The key effector complex of the RNA interference pathway consists of small interfering RNA molecules (siRNAs) associated with Argonaute, assembled into the RNA-induced transcriptional silencing (RITS) complex. This review focuses on our current understanding of how RITS promotes heterochromatin formation, and in particular on the role of Argonaute-containing complexes in many other functions such as quelling, release of RNA polymerases, cellular quiescence and genome defense.
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Affiliation(s)
- Sonali Bhattacharjee
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
| | - Benjamin Roche
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
| | - Robert A Martienssen
- a Cold Spring Harbor Laboratory, Howard Hughes Medical Institute , Cold Spring Harbor , NY , USA
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90
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RNA-Targeted Antiviral Immunity: More Than Just RNA Silencing. Trends Microbiol 2019; 27:792-805. [PMID: 31213342 DOI: 10.1016/j.tim.2019.05.007] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/08/2019] [Accepted: 05/15/2019] [Indexed: 11/21/2022]
Abstract
RNA silencing is a fundamental, evolutionarily conserved mechanism that regulates gene expression in eukaryotes. It also functions as a primary immune defense in microbes, such as viruses in plants. In addition to RNA silencing, RNA decay and RNA quality-control pathways are also two ancestral forms of intrinsic antiviral immunity, and the three RNA-targeted pathways may operate cooperatively for their antiviral function. Plant viruses encode viral suppressors of RNA silencing (VSRs) to suppress RNA silencing and facilitate virus infection. In response, plants may activate a counter-counter-defense mechanism to cope with VSR-mediated RNA silencing suppression. In this review, we summarize current knowledge of RNA silencing, RNA decay, and RNA quality control in antiviral defense, and highlight the mechanisms by which viruses compromise RNA-targeted immunity for their infection and survival in plants.
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91
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Mauck KE, Kenney J, Chesnais Q. Progress and challenges in identifying molecular mechanisms underlying host and vector manipulation by plant viruses. CURRENT OPINION IN INSECT SCIENCE 2019; 33:7-18. [PMID: 31358199 DOI: 10.1016/j.cois.2019.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 12/28/2018] [Accepted: 01/05/2019] [Indexed: 06/10/2023]
Abstract
Plant virus infection fundamentally alters chemical and behavioral phenotypes of hosts and vectors. These alterations often enhance virus transmission, leading researchers to surmise that such effects are manipulations caused by virus adaptations and not just by-products of pathology. But identification of the virus components behind manipulation is missing from most studies performed to date. Here, we evaluate causative empirical evidence that virus components are the drivers of manipulated host and vector phenotypes. To do so, we link findings and methodologies on virus pathology with observational and functional genomics studies on virus manipulation. Our synthesis provides an overview of progress, areas of synergy, and new approaches that will lead to an improved mechanistic understanding of host and vector manipulation by plant viruses.
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Affiliation(s)
- Kerry E Mauck
- Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA.
| | - Jaimie Kenney
- Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA
| | - Quentin Chesnais
- Department of Entomology, University of California, Riverside, Riverside, CA 92521, USA
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92
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Li Y, Sun Q, Zhao T, Xiang H, Zhang X, Wu Z, Zhou C, Zhang X, Wang Y, Zhang Y, Wang X, Li D, Yu J, Dinesh‐Kumar SP, Han C. Interaction between Brassica yellows virus silencing suppressor P0 and plant SKP1 facilitates stability of P0 in vivo against degradation by proteasome and autophagy pathways. THE NEW PHYTOLOGIST 2019; 222:1458-1473. [PMID: 30664234 PMCID: PMC6593998 DOI: 10.1111/nph.15702] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 01/08/2019] [Indexed: 05/21/2023]
Abstract
P0 protein of some polerovirus members can target ARGONAUTE1 (AGO1) to suppress RNA silencing. Although P0 harbors an F-box-like motif reported to be essential for interaction with S phase kinase-associated protein 1 (SKP1) and RNA silencing suppression, it is the autophagy pathway that was shown to contribute to AGO1 degradation. Therefore, the role of P0-SKP1 interaction in silencing suppression remains unclear. We conducted global mutagenesis and comparative functional analysis of P0 encoded by Brassica yellows virus (BrYV) (P0Br ). We found that several residues within P0Br are required for local and systemic silencing suppression activities. Remarkably, the F-box-like motif mutant of P0Br , which failed to interact with SKP1, is destabilized in vivo. Both the 26S proteasome system and autophagy pathway play a role in destabilization of the mutant protein. Furthermore, silencing of a Nicotiana benthamiana SKP1 ortholog leads to the destabilization of P0Br . Genetic analyses indicated that the P0Br -SKP1 interaction is not directly required for silencing suppression activity of P0Br , but it facilitates stability of P0Br to ensure efficient RNA silencing suppression. Consistent with these findings, efficient systemic infection of BrYV requires P0Br . Our results reveal a novel strategy used by BrYV for facilitating viral suppressors of RNA silencing stability against degradation by plant cells.
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Affiliation(s)
- Yuanyuan Li
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Qian Sun
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Tianyu Zhao
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Haiying Xiang
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Xiaoyan Zhang
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Zhanyu Wu
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Cuiji Zhou
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Xin Zhang
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Ying Wang
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
| | - Yongliang Zhang
- State Key Laboratory of Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Soil MicrobiologyCollege of Biological SciencesChina Agricultural UniversityBeijing100193China
| | - Xianbing Wang
- State Key Laboratory of Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Soil MicrobiologyCollege of Biological SciencesChina Agricultural UniversityBeijing100193China
| | - Dawei Li
- State Key Laboratory of Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Soil MicrobiologyCollege of Biological SciencesChina Agricultural UniversityBeijing100193China
| | - Jialin Yu
- State Key Laboratory of Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Soil MicrobiologyCollege of Biological SciencesChina Agricultural UniversityBeijing100193China
| | - Savithramma P. Dinesh‐Kumar
- Department of Plant Biology and The Genome CenterCollege of Biological SciencesUniversity of California, DavisDavisCA95616USA
| | - Chenggui Han
- State Key Laboratory for Agro‐Biotechnology and Ministry of Agriculture Key Laboratory of Pest Monitoring and Green ManagementChina Agricultural UniversityBeijing100193China
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93
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Hu T, Huang C, He Y, Castillo-González C, Gui X, Wang Y, Zhang X, Zhou X. βC1 protein encoded in geminivirus satellite concertedly targets MKK2 and MPK4 to counter host defense. PLoS Pathog 2019; 15:e1007728. [PMID: 30998777 PMCID: PMC6499421 DOI: 10.1371/journal.ppat.1007728] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 05/03/2019] [Accepted: 03/24/2019] [Indexed: 12/30/2022] Open
Abstract
Plant viruses have evolved multiple strategies to overcome host defense to establish an infection. Here, we identified two components of a host mitogen-activated protein kinase (MAPK) cascade, MKK2 and MPK4, as bona fide targets of the βC1 protein encoded by the betasatellite of tomato yellow leaf curl China virus (TYLCCNV). βC1 interacts with the kinase domain of MKK2 and inhibits its activity. In vivo, βC1 suppresses flagellin-induced MAPK activation and downstream responses by targeting MKK2. Furthermore, βC1 also interacts with MPK4 and inhibits its kinase activity. TYLCCNV infection induces the activation of the MAPK cascade, mutation in MKK2 or MPK4 renders the plant more susceptible to TYLCCNV, and can complement the lack of βC1. This work shows for the first time that a plant virus both activates and suppresses a MAPK cascade, and the discovery of the ability of βC1 to selectively interfere with the host MAPK activation illustrates a novel virulence function and counter-host defense mechanism of geminiviruses.
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Affiliation(s)
- Tao Hu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
| | - Changjun Huang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yuting He
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Claudia Castillo-González
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, United States of America
| | - Xiaojian Gui
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Yaqin Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States of America
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, United States of America
| | - Xueping Zhou
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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94
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Ban Y, Morita Y, Ogawa M, Higashi K, Nakatsuka T, Nishihara M, Nakayama M. Inhibition of post-transcriptional gene silencing of chalcone synthase genes in petunia picotee petals by fluacrypyrim. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1513-1523. [PMID: 30690559 DOI: 10.1093/jxb/erz009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
In petals of picotee petunia (Petunia hybrida) cultivars, margin-specific post-transcriptional gene silencing (PTGS) of chalcone synthase A (CHSA) inhibits anthocyanin biosynthesis, resulting in marginal white tissue formation. In this study, we found that a low molecular mass compound, fluacrypyrim, inhibits PTGS of CHSA, and we explored the site-specific PTGS mechanism of operation. Fluacrypyrim treatment abolished the picotee pattern and eliminated site-specific differences in the levels of anthocyanin-related compounds, CHSA expression, and CHSA small interfering RNA (siRNA). In addition, fluacrypyrim abolished the petunia star-type pattern, which is also caused by PTGS of CHSA. Fluacrypyrim treatment was effective only at the early floral developmental stage and predominantly eliminated siRNA derived from CHS genes; i.e. siRNA derived from other genes remained at a comparable level. Fluacrypyrim probably targets the induction of PTGS that specifically operates for CHS genes in petunia picotee flowers, rather than common PTGS maintenance mechanisms that degrade mRNAs and generate siRNA. Upon treatment, the proportion of colored tissue increased due to a shift of the border between white and colored sites toward the margin in a time- and dose-dependent manner. These findings imply that the fluacrypyrim-targeted PTGS induction is completed gradually and its strength is attenuated from the margins to the center of petunia picotee petals.
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Affiliation(s)
- Yusuke Ban
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
- Western Region Agricultural Research Center, NARO, Fukuyama, Hiroshima, Japan
| | - Yasumasa Morita
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
- Experimental Farm, Faculty of Agriculture, Meijo University, Kasugai, Aichi, Japan
| | - Mika Ogawa
- Teikyo University of Science, Adachi, Tokyo, Japan
| | | | - Takashi Nakatsuka
- Iwate Biotechnology Research Center, Kitakami, Iwate, Japan
- Graduate School of Agriculture, Shizuoka University, Shizuoka, Shizuoka, Japan
| | | | - Masayoshi Nakayama
- Institute of Vegetable and Floriculture Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
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95
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Liu D, Zhao Q, Cheng Y, Li D, Jiang C, Cheng L, Wang Y, Yang A. Transcriptome analysis of two cultivars of tobacco in response to Cucumber mosaic virus infection. Sci Rep 2019; 9:3124. [PMID: 30816259 PMCID: PMC6395745 DOI: 10.1038/s41598-019-39734-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 01/31/2019] [Indexed: 01/23/2023] Open
Abstract
Cucumber mosaic virus (CMV) is among the most important plant virus infections, inducing a variety of disease symptoms. However, the molecular mechanisms underlying plant responses to CMV infection remain poorly understood. In this study, we performed RNA sequencing analysis of tolerant (Taiyan8) and susceptible (NC82) tobacco cultivars on CMV-infected plants, using mock-inoculated plants as a control. The propagation of CMV in inoculated leaves did not show obvious difference between two cultivars, whereas virus accumulation in systemic leaves of Taiyan8 was smaller than those of NC82 at the same time point. We observed 765 and 1,011 differentially expressed genes (DEGs) in Taiyan8 and NC82, respectively, in CMV-inoculated leaves. DEGs related to reactive oxygen species, salicylic acid signal transduction, and plant-pathogen interaction were upregulated or downregulated in Taiyan8, which indicates that defense response pathways to CMV were activated in the tolerant cultivar. In addition, we identified several DEGs related to disease defense and stress resistance showing opposing expression patterns in the two cultivars. Our comparative transcriptome analysis will improve our understanding of the mechanisms of CMV tolerance in plants, and will be of great importance in the molecular breeding of CMV- tolerant genotypes.
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Affiliation(s)
- Dan Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Qiang Zhao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yazeng Cheng
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Dandan Li
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Caihong Jiang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Lirui Cheng
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Yuanying Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Aiguo Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China.
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96
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Rashid MO, Zhang XY, Wang Y, Li DW, Yu JL, Han CG. The Three Essential Motifs in P0 for Suppression of RNA Silencing Activity of Potato leafroll virus Are Required for Virus Systemic Infection. Viruses 2019; 11:E170. [PMID: 30791535 PMCID: PMC6410027 DOI: 10.3390/v11020170] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/14/2019] [Accepted: 02/16/2019] [Indexed: 12/19/2022] Open
Abstract
Higher plants exploit posttranscriptional gene silencing as a defense mechanism against virus infection by the RNA degradation system. Plant RNA viruses suppress posttranscriptional gene silencing using their encoded proteins. Three important motifs (F-box-like motif, G139/W140/G141-like motif, and C-terminal conserved region) in P0 of Potato leafroll virus (PLRV) were reported to be essential for suppression of RNA silencing activity. In this study, Agrobacterium-mediated transient experiments were carried out to screen the available amino acid substitutions in the F-box-like motif and G139/W140/G141-like motif that abolished the RNA silencing suppression activity of P0, without disturbing the P1 amino acid sequence. Subsequently, four P0 defective mutants derived from a full-length cDNA clone of PLRV (L76F and W87R substitutions in the F-box-like motif, G139RRR substitution in the G139/W140/G141-like motif, and F220R substitution in the C-terminal conserved region) were successfully generated by reverse PCR and used to investigate the impact of these substitutions on PLRV infectivity. The RT-PCR and western blot analysis revealed that these defective mutants affected virus accumulation in inoculated leaves and systemic movement in Nicotiana benthamiana as well as in its natural hosts, potato and black nightshade. These results further demonstrate that the RNA silencing suppressor of PLRV is required for PLRV accumulation and systemic infection.
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Affiliation(s)
- Mamun-Or Rashid
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Xiao-Yan Zhang
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Ying Wang
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Da-Wei Li
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Jia-Lin Yu
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
| | - Cheng-Gui Han
- State Key Laboratory for Agrobiotechnology and Key Laboratory of Pest Monitoring and Green Management, MOA, China Agricultural University, Beijing 100193, China.
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97
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Yin Z, Murawska Z, Xie F, Pawełkowicz M, Michalak K, Zhang B, Lebecka R. microRNA response in potato virus Y infected tobacco shows strain-specificity depending on host and symptom severity. Virus Res 2019; 260:20-32. [PMID: 30423361 DOI: 10.1016/j.virusres.2018.11.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 12/20/2022]
Abstract
The present study demonstrates how different potato virus Y (PVY) strains affect the miRNA balance in tobacco cv. Samsun. The two prevalent strains PVYNTN and PVYN-Wi caused severe and mild veinal necrosis (VN) respectively, and the unique PVYZ-NTN strain induced milder vein clearing (VCl) in the upper non-inoculated leaves. A single amino acid polymorphisms (SAPs) I252V and a Q412 to R412 substitution in the HC-Pro cistron of the PVYZ-NTN strain might relate to the loss of VN in tobacco. The abundance of 18 out of the 26 tested miRNAs was increased upon infection by the severe strains PVYNTN and PVYN-Wi. Expression of a group of defense related transcripts were increased accordingly. Two miRNAs, nta-miR6020a-5p and nta-miR6164a/b, which target the TIR-NBS-LRR type resistant TMV N genes involving in signal transduction, might correlate with the PVYNTN and PVYN-Wi induced VN. The down-regulated mRNAs, e.g., RAP2-7 and TOE3, PXC3, LRR-RLK, ATHB-14 and TCP4 targeted by nta-miR172, nta-miR390, nta-miR482, nta-miR166 and nta-miR319/159 respectively, were related to regulation of transcription, protein phosphorylation and cell differentiation. The observed strain-specific alteration of miRNAs and their targets are host dependent and corresponds to the symptom severity and the viral HC-Pro RNA levels.
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Affiliation(s)
- Zhimin Yin
- Plant Breeding and Acclimatization Institute - National Research Institute, Młochów Research Center, Platanowa 19, PL-05-831, Młochów, Poland.
| | - Zofia Murawska
- Plant Breeding and Acclimatization Institute - National Research Institute, Młochów Research Center, Platanowa 19, PL-05-831, Młochów, Poland
| | - Fuliang Xie
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Magdalena Pawełkowicz
- Department of Plant Genetics, Breeding & Biotechnology, Faculty of Horticulture, Biotechnology and Landscape Architecture, Warsaw University of Life Sciences - SGGW, Nowoursynowska Street 159, PL-02-776, Warsaw, Poland
| | - Krystyna Michalak
- Plant Breeding and Acclimatization Institute - National Research Institute, Młochów Research Center, Platanowa 19, PL-05-831, Młochów, Poland
| | - Baohong Zhang
- Department of Biology, East Carolina University, Greenville, NC, 27858, USA
| | - Renata Lebecka
- Plant Breeding and Acclimatization Institute - National Research Institute, Młochów Research Center, Platanowa 19, PL-05-831, Młochów, Poland
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98
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RNA Interference: A Natural Immune System of Plants to Counteract Biotic Stressors. Cells 2019; 8:cells8010038. [PMID: 30634662 PMCID: PMC6356646 DOI: 10.3390/cells8010038] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/01/2019] [Accepted: 01/07/2019] [Indexed: 02/06/2023] Open
Abstract
During plant-pathogen interactions, plants have to defend the living transposable elements from pathogens. In response to such elements, plants activate a variety of defense mechanisms to counteract the aggressiveness of biotic stressors. RNA interference (RNAi) is a key biological process in plants to inhibit gene expression both transcriptionally and post-transcriptionally, using three different groups of proteins to resist the virulence of pathogens. However, pathogens trigger an anti-silencing mechanism through the expression of suppressors to block host RNAi. The disruption of the silencing mechanism is a virulence strategy of pathogens to promote infection in the invaded hosts. In this review, we summarize the RNA silencing pathway, anti-silencing suppressors, and counter-defenses of plants to viral, fungal, and bacterial pathogens.
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99
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Guo H, Gu L, Liu F, Chen F, Ge F, Sun Y. Aphid-borne Viral Spread Is Enhanced by Virus-induced Accumulation of Plant Reactive Oxygen Species. PLANT PHYSIOLOGY 2019; 179:143-155. [PMID: 30381318 PMCID: PMC6324229 DOI: 10.1104/pp.18.00437] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 10/23/2018] [Indexed: 05/24/2023]
Abstract
Most known plant viruses are spread from plant to plant by insect vectors. There is strong evidence that nonpersistently transmitted viruses manipulate the release of plant volatiles to attract insect vectors, thereby promoting virus spread. The mechanisms whereby aphid settling and feeding is altered on plants infected with these viruses, however, are unclear. Here we employed loss-of-function mutations in cucumber mosaic virus (CMV) and one of its host plants, tobacco (Nicotiana tabacum), to elucidate such mechanisms. We show that, relative to a CMVΔ2b strain with a deletion of the viral suppressor of RNAi 2b protein in CMV, plants infected with wild-type CMV produce higher concentrations of the reactive oxygen species (ROS) H2O2 in plant tissues. Aphids on wild-type CMV-infected plants engage in shorter probes, less phloem feeding, and exhibit other changes, as detected by electrical penetration graphing technology, relative to CMVΔ2b-infected plants. Therefore, the frequency of virus acquisition and the virus load per aphid were greater on CMV-infected plants than on CMVΔ2b-infected plants. Aphids also moved away from initial feeding sites more frequently on wild-type CMV infected versus CMVΔ2b-infected plants. The role of H2O2 in eliciting these effects on aphids was corroborated using healthy plants infused with H2O2 Finally, H2O2 levels were not elevated, and aphid behavior was unchanged, on CMV-infected RbohD-silenced tobacco plants, which are deficient in the induction of ROS production. These results suggest that CMV uses its viral suppressor of RNAi protein to increase plant ROS levels, thereby enhancing its acquisition and transmission by vector insects.
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Affiliation(s)
- Huijuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Liyuan Gu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Fanqi Liu
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Fajun Chen
- University of Chinese Academy of Sciences, Beijing, China
| | - Feng Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yucheng Sun
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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100
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Islam W, Naveed H, Zaynab M, Huang Z, Chen HYH. Plant defense against virus diseases; growth hormones in highlights. PLANT SIGNALING & BEHAVIOR 2019; 14:1596719. [PMID: 30957658 PMCID: PMC6546145 DOI: 10.1080/15592324.2019.1596719] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/12/2019] [Indexed: 05/20/2023]
Abstract
Phytohormones are critical in various aspects of plant biology such as growth regulations and defense strategies against pathogens. Plant-virus interactions retard plant growth through rapid alterations in phytohormones and their signaling pathways. Recent research findings show evidence of how viruses impact upon modulation of various phytohormones affecting plant growth regulations. The opinion is getting stronger that virus-mediated phytohormone disruption and alteration weaken plant defense strategies through enhanced replication and systemic spread of viral particles. These hormones regulate plant-virus interactions in various ways that may involve antagonism and cross talk to modulate small RNA (sRNA) systems. The article aims to highlight the recent research findings elaborating the impact of viruses upon manipulation of phytohormones and virus biology.
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Affiliation(s)
- Waqar Islam
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
| | - Hassan Naveed
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Madiha Zaynab
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhiqun Huang
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
- Zhiqun Huang Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China
| | - Han Y. H. Chen
- Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, China
- Institute of Geography, Fujian Normal University, Fuzhou, China
- Faculty of Natural Resources Management, Lakehead University, Ontario, Canada
- CONTACT Han Y. H. Chen Faculty of Natural Resources Management, Lakehead University, Ontario Canada
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