scholarly journals Interference with jasmonic acid-regulated gene expression is a general property of viral suppressors of RNA silencing but only partly explains virus-induced changes in plant–aphid interactions

2014 ◽  
Vol 95 (3) ◽  
pp. 733-739 ◽  
Author(s):  
Jack H. Westwood ◽  
Mathew G. Lewsey ◽  
Alex M. Murphy ◽  
Trisna Tungadi ◽  
Anne Bates ◽  
...  
Keyword(s):  
Gene Expression ◽  
Jasmonic Acid ◽  
Mosaic Virus ◽  
Potato Virus ◽  
Rna Silencing ◽  
Potato Virus X ◽  
Host Responses ◽  
Regulated Gene Expression ◽  
Viral Determinants ◽  
Induced Changes

The cucumber mosaic virus (CMV) 2b viral suppressor of RNA silencing (VSR) inhibits host responses to jasmonic acid (JA), a chemical signal regulating resistance to insects. Previous experiments with a CMV subgroup IA strain and its 2b gene deletion mutant suggested that VSRs might neutralize aphid (Myzus persicae) resistance by inhibiting JA-regulated gene expression. To further investigate this, we examined JA-regulated gene expression and aphid performance in Nicotiana benthamiana infected with Potato virus X, Potato virus Y, Tobacco mosaic virus and a subgroup II CMV strain, as well as in transgenic plants expressing corresponding VSRs (p25, HC-Pro, 126 kDa and 2b). All the viruses or their VSRs inhibited JA-induced gene expression. However, this did not always correlate with enhanced aphid performance. Thus, VSRs are not the sole viral determinants of virus-induced changes in host–aphid interactions and interference with JA-regulated gene expression cannot completely explain enhanced aphid performance on virus-infected plants.

scholarly journals Phenotypes and Functional Effects Caused by Various Viral RNA Silencing Suppressors in Transgenic Nicotiana benthamiana and N. tabacum

2008 ◽  
Vol 21 (2) ◽  
pp. 178-187 ◽  
Author(s):  
Shahid Aslam Siddiqui ◽  
Cecilia Sarmiento ◽  
Erkki Truve ◽  
Harry Lehto ◽  
Kirsi Lehto
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Nicotiana Benthamiana ◽  
Rna Silencing ◽  
Fluorescent Protein ◽  
Potato Virus X ◽  
Mottle Virus ◽  
African Cassava Mosaic Virus ◽  
Rice Yellow Mottle Virus ◽  
Green Fluorescent

RNA silencing suppressor genes derived from six virus genera were transformed into Nicotiana benthamiana and N. tabacum plants. These suppressors were P1 of Rice yellow mottle virus (RYMV), P1 of Cocksfoot mottle virus, P19 of Tomato bushy stunt virus, P25 of Potato virus X, HcPro of Potato virus Y (strain N), 2b of Cucumber mosaic virus (strain Kin), and AC2 of African cassava mosaic virus (ACMV). HcPro caused the most severe phenotypes in both Nicotiana spp. AC2 also produced severe effects in N. tabacum but a much milder phenotype in N. benthamiana, although both HcPro and AC2 affected the leaf tissues of the two Nicotiana spp. in similar ways, causing hyperplasia and hypoplasia, respectively. P1-RYMV caused high lethality in the N. benthamiana plants but only mild effects in the N. tabacum plants. Phenotypic alterations produced by the other transgenes were minor in both species. Interestingly, the suppressors had very different effects on crucifer-infecting Tobamovirus (crTMV) infections. AC2 enhanced both spread and brightness of the crTMV-green fluorescent protein (GFP) lesions, whereas 2b and both P1 suppressors enhanced spread but not brightness of these lesions. P19 promoted spread of the infection into new foci within the infiltrated leaf, whereas HcPro and P25 suppressed the spread of crTMV-GFP lesions.

scholarly journals The cysteine-rich proteins of beet necrotic yellow vein virus and tobacco rattle virus contribute to efficient suppression of silencing in roots

2012 ◽  
Vol 93 (8) ◽  
pp. 1841-1850 ◽  
Author(s):  
Ida Bagus Andika ◽  
Hideki Kondo ◽  
Masamichi Nishiguchi ◽  
Tetsuo Tamada
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Rna Silencing ◽  
Tobacco Rattle Virus ◽  
Potato Virus X ◽  
Plant Viruses ◽  
Yellow Vein ◽  
Negative Strand ◽  
Silencing Suppression ◽  
Leaves And Roots

Many plant viruses encode proteins that suppress RNA silencing, but little is known about the activity of silencing suppressors in roots. This study examined differences in the silencing suppression activity of different viruses in leaves and roots of Nicotiana benthamiana plants. Infection by tobacco mosaic virus, potato virus Y and cucumber mosaic virus but not potato virus X (PVX) resulted in strong silencing suppression activity of a transgene in both leaves and roots, whereas infection by beet necrotic yellow vein virus (BNYVV) and tobacco rattle virus (TRV) showed transgene silencing suppression in roots but not in leaves. For most viruses tested, viral negative-strand RNA accumulated at a very low level in roots, compared with considerable levels of positive-strand genomic RNA. Co-inoculation of leaves with PVX and either BNYVV or TRV produced an increase in PVX negative-strand RNA and subgenomic RNA (sgRNA) accumulation in roots. The cysteine-rich proteins (CRPs) BNYVV p14 and TRV 16K showed weak silencing suppression activity in leaves. However, when either of these CRPs was expressed from a PVX vector, there was an enhancement of PVX negative-strand RNA and sgRNA accumulation in roots compared with PVX alone. Such enhancement of PVX sgRNAs was also observed by expression of CRPs of other viruses and the well-known suppressors HC-Pro and p19 but not of the potato mop-top virus p8 CRP. These results indicate that BNYVV- and TRV-encoded CRPs suppress RNA silencing more efficiently in roots than in leaves.

scholarly journals Biodistribution of Filamentous Plant Virus Nanoparticles: Pepino Mosaic Virus versus Potato Virus X

2018 ◽  
Vol 20 (1) ◽  
pp. 469-477 ◽  
Author(s):  
Duc H. T. Le ◽  
Eduardo Méndez-López ◽  
Chao Wang ◽  
Ulrich Commandeur ◽  
Miguel A. Aranda ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Plant Virus ◽  
Potato Virus X ◽  
Pepino Mosaic Virus ◽  
Virus Versus

scholarly journals Epidemic of Potato virus Y and Cucumber mosaic virus in Henan Province Tobacco

Plant Disease ◽  
2001 ◽  
Vol 85 (4) ◽  
pp. 447-447 ◽  
Author(s):  
X. D. Li ◽  
Y. Q. Li ◽  
H. G. Wang
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Early Stage ◽  
Potato Virus X ◽  
Henan Province ◽  
Enzyme Linked Immunosorbent Assay ◽  
Resistant Varieties ◽  
Vein Necrosis

Flue-cured tobacco is an important crop in Henan Province, China. During the 2000 growing season, many tobacco plants showed various degrees of mottling, mosaic, vein clearing, or vein necrosis in most of the counties. Some plants even died at an early stage of growth. A survey was conducted in May-June in several tobacco-growing counties, and the incidence of symptomatic plants in individual fields ranged from 10 to 85%. The most widely planted tobacco varieties, NC89, K326, and K346, were highly susceptible. Symptomatic plants were collected from Jiaxian and Xiangcheng counties and samples were tested by enzyme-linked immunosorbent assay for Tobacco mosaic virus (TMV), Cucumber mosaic virus (CMV), Potato virus Y (PVY), and Potato virus X (PVX). Of 65 samples tested, 21 were positive for only PVY, 16 positive for only CMV, one each was positive for only TMV or PVX. Nineteen samples were doubly infected with various combinations of these viruses and six were infected with combinations of three viruses. The causal agent(s) in the remaining sample could not be determined. In total, CMV was detected in 40 samples, PVY in 38, PVX in 10, and TMV in 7 samples. TMV and CMV used to be the most important viruses and PVY occurred only rarely. But PVY has become prevalent in Henan and in neighboring Shandong province (2). CMV and TMV were reported to be the most prevalent viruses in Shanxi (1) and Fujian Provinces (3). Because resistant varieties are not available, and mixed infections are more common, the results presented here explain why huge damage is occurring in tobacco crops in recent years. Some varieties are partially resistant to TMV and CMV but the varieties commonly grown are highly susceptible to PVY. Therefore, breeding for resistance to viruses, especially to PVY, is urgent to control the occurrence of tobacco viral diseases. References: (1) J. L. Cheng et al. Acta Tabacaria Sin. 4:43, 1998. (2) J. B. Wang et al. Chinese Tobacco Sci. 1:26, 1998. (3) L. H. Xie et al. Acta Tabacaria Sin. 2:25, 1994.

scholarly journals Involvement of the chloroplast gene ferredoxin 1 in multiple responses of Nicotiana benthamiana to Potato virus X infection

2019 ◽  
Vol 71 (6) ◽  
pp. 2142-2156 ◽  
Author(s):  
Xue Yang ◽  
Yuwen Lu ◽  
Fang Wang ◽  
Ying Chen ◽  
Yanzhen Tian ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Mosaic Virus ◽  
Potato Virus ◽  
Tobacco Rattle Virus ◽  
Potato Virus X ◽  
Tomato Mosaic Virus ◽  
Pcr Analysis ◽  
Coat Proteins ◽  
Virus Induced Gene Silencing ◽  
Callose Deposition

Abstract The chloroplast protein ferredoxin 1 (FD1), with roles in the chloroplast electron transport chain, is known to interact with the coat proteins (CPs) of Tomato mosaic virus and Cucumber mosaic virus. However, our understanding of the roles of FD1 in virus infection remains limited. Here, we report that the Potato virus X (PVX) p25 protein interacts with FD1, whose mRNA and protein levels are reduced by PVX infection or by transient expression of p25. Silencing of FD1 by Tobacco rattle virus-based virus-induced gene silencing (VIGS) promoted the local and systemic infection of plants by PVX. Use of a drop-and-see (DANS) assay and callose staining revealed that the permeability of plasmodesmata (PDs) was increased in FD1-silenced plants together with a consistently reduced level of PD callose deposition. After FD1 silencing, quantitative reverse transcription–real-time PCR (qRT–PCR) analysis and LC-MS revealed these plants to have a low accumulation of the phytohormones abscisic acid (ABA) and salicylic acid (SA), which contributed to the decreased callose deposition at PDs. Overexpression of FD1 in transgenic plants manifested resistance to PVX infection, but the contents of ABA and SA, and the PD callose deposition were not increased in transgenic plants. Overexpression of FD1 interfered with the RNA silencing suppressor function of p25. These results demonstrate that interfering with FD1 function causes abnormal plant hormone-mediated antiviral processes and thus enhances PVX infection.

scholarly journals Rice Stripe Mosaic Virus–Encoded P4 Is a Weak Suppressor of Viral RNA Silencing and Is Required for Disease Symptom Development

2020 ◽  
Vol 33 (3) ◽  
pp. 412-422
Author(s):  
Chao Zhang ◽  
Dong Chen ◽  
Guoyi Yang ◽  
Xiyuan Yu ◽  
Jianguo Wu
Keyword(s):  
Mosaic Virus ◽  
Rna Silencing ◽  
Matrix Protein ◽  
Expression System ◽  
Potato Virus X ◽  
Bimolecular Fluorescence Complementation ◽  
Developmental Defects ◽  
The Matrix ◽  
Silencing Pathways ◽  
Viral Suppressors

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.

scholarly journals Solution structures of potato virus X and narcissus mosaic virus from Raman optical activity

2002 ◽  
Vol 83 (1) ◽  
pp. 241-246 ◽  
Author(s):  
Ewan W. Blanch ◽  
David J. Robinson ◽  
Lutz Hecht ◽  
Christopher D. Syme ◽  
Kurt Nielsen ◽  
...  
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Optical Activity ◽  
Potato Virus ◽  
Potato Virus X ◽  
Protein Subunit ◽  
Helix Bundle ◽  
Raman Optical Activity ◽  
Α Helix ◽  
Narcissus Mosaic Virus

Potato virus X (PVX) and narcissus mosaic virus (NMV) were studied using vibrational Raman optical activity (ROA) in order to obtain new information on the structures of their coat protein subunits. The ROA spectra of the two intact virions are very similar to each other and similar to that of tobacco mosaic virus (TMV) studied previously, being dominated by signals characteristic of proteins with helix bundle folds. In particular, PVX and NMV show strong positive ROA bands at ∼1340 cm−1 assigned to hydrated α-helix and perhaps originating in surface exposed helical residues, together with less strong positive ROA intensity in the range ∼1297–1312 cm−1 assigned to α-helix in a more hydrophobic environment and perhaps originating in residues at helix–helix interfaces. The positive ∼1340 cm−1 ROA band of TMV is less intense than those of PVX and NMV, suggesting that TMV contains less hydrated α-helix. Small differences in other spectral regions reflect differences in some loop, turn and side-chain compositions and conformations among the three viruses. A pattern recognition program based on principal component analysis of ROA spectra indicates that the coat protein subunit folds of PVX and NMV may be very similar to each other and similar to that of TMV. These results suggest that PVX and NMV may have coat protein subunit structures based on folds similar to the TMV helix bundle and hence that the helical architecture of the PVX and NMV particles may be similar to that of TMV but with different structural parameters.

scholarly journals First Report of Tomato torrado virus Infecting Tomato in Colombia

Plant Disease ◽  
2012 ◽  
Vol 96 (4) ◽  
pp. 592-592 ◽  
Author(s):  
M. Verbeek ◽  
A. M. Dullemans
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Polyclonal Antibodies ◽  
Sandwich Elisa ◽  
Potato Virus X ◽  
Rt Pcr ◽  
Leaf Extracts ◽  
Serological Tests ◽  
First Report ◽  
Initial Symptoms

Tomato (Solanum lycopersicum L.) plants grown in plastic greenhouses near Villa de Leyva, northeast of Bogota, Colombia showed necrotic spots on the leaves in September 2008. Initial symptoms were necrosis beginning at the base of leaflets that were surrounded by yellow areas. These symptoms resembled those described for Tomato torrado virus (ToTV; family Secoviridae, genus Torradovirus), which was first found in Spain (2). Other (tentative) members of the genus Torradovirus, Tomato marchitez virus (ToMarV), Tomato chocolate spot virus (ToChSV), and Tomato chocolàte virus (ToChV) (3) induce similar symptoms on tomato plants. One sample, coded T418, was stored in the freezer and brought to our lab in 2011. Serological tests (double-antibody sandwich-ELISA) using polyclonal antibodies (Prime Diagnostics, Wageningen, The Netherlands) on leaf extracts showed the absence of Pepino mosaic virus (PepMV), Tobacco mosaic virus (TMV), Tomato spotted wilt virus (TSWV), Cucumber mosaic virus (CMV), Potato virus X (PVX), and Potato virus Y (PVY). Leaf extracts were mechanically inoculated onto the indicator plants Physalis floridana, Nicotiana hesperis ‘67A’, and N. occidentalis ‘P1’ (six plants in total) and were kept in a greenhouse at 20°C with 16 h of light. Necrotic symptoms appeared 4 to 5 days postinoculation and resembled those described for ToTV (2). Two dip preparations of systemically infected P. floridana and N. occidentalis leaves were examined by electron microscopy, which revealed the presence of spherical virus particles of approximately 30 nm. To confirm the presence of ToTV, total RNA was extracted from the original leaf material and an inoculated P. floridana and N. occidentalis plant using the Qiagen Plant Mini Kit (Qiagen, Hilden, Germany) following manufacturer's instructions. ToTV-specific primer sets ToTV-Dp33F/ToTV-Dp20R (5′-TGCTCAATGTTGGAAACCCC-3′/5′-AGCCCTTCATAGGCTAGCC-3′, amplifying a fragment of the RNA1 polyprotein with an expected size of 751 bp) and ToTV-Dp1F/ToTV-Dp2R (5′-ACAAGAGGAGCTTGACGAGG-3′/5′-AAAGGTAGTGTAATGGTCGG-3′, amplifying a fragment on the RNA2 movement protein region with an expected size of 568 bp) were used to amplify the indicated regions in a reverse transcription (RT)-PCR using the One-Step Access RT-PCR system (Promega, Madison, WI). Amplicons of the predicted size were obtained in all tested materials. The PCR products were purified with the Qiaquick PCR Purification Kit (Qiagen) and sequenced directly. BLAST analyses of the obtained sequences (GenBank Accession Nos. JQ314230 and JQ314229) confirmed the identity of isolate T418 as ToTV, with 99% identity to isolate PRI-ToTV0301 in both fragments (GenBank Accession Nos. DQ388879 and DQ388880 for RNA1 and RNA 2, respectively). To our knowledge, this is the first report of ToTV in Colombia, and interestingly, since ToTV has been found only in Europe and Australia (1) so far, this is the first report of ToTV on the American continent. References: (1) C. F. Gambley et al. Plant Dis. 94:486, 2010. (2) M. Verbeek et al. Arch. Virol. 152:881, 2007. (3) M. Verbeek et al. Arch. Virol. 155:751, 2010.

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