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Ringspot Virus (ringspot + virus)
Selected AbstractsRT-PCR Detection of Odontoglossum ringspot virus, Cymbidium mosaic virus and Tospoviruses and Association of Infections with Leaf-Yellowing Symptoms in PhalaenopsisJOURNAL OF PHYTOPATHOLOGY, Issue 5 2008K. Yamane Abstract Leaf-yellowing symptoms in Phalaenopsis are most important effects in its commercial production in Japan and their cause has not yet been clarified. In the present study, Odontoglossum ringspot virus (ORSV), Cymbidium mosaic virus (CymMV) and tospoviruses were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) in Phalaenopsis showing leaf-yellowing symptoms. Ring, spot, mosaic, necrosis and other symptom types were observed in 42%, 24%, 25%, 16% and 44% of the tested plants respectively. ORSV was detected in 55% of the plants, particularly in 35 of 42 plants with ring symptoms. CymMV was detected in 34% of the plants, particularly in 18 of 25 plants with mosaic symptoms. Plants co-infected with both viruses tended to show severe symptoms. In spite of systemic infection by inoculation of ORSV, no clear ring symptoms were observed in any plant for 6 months. Symptoms of leaf-yellowing were significantly reduced after 3 months. These results suggest that the symptoms can be associated with the viruses but occurred and alleviated over time and by changes in the environmental conditions. No tospoviruses were detected in 70 tested plants. ORSV and CymMV were simultaneously detected by RT-PCR using reported primers for ORSV and newly designed primers for CymMV using an efficient direct tube RNA extraction technique providing more cost-effective RT-PCR screening. No viruses were detected by RT-PCR in several plants showing spot or ring symptoms, suggesting the presence of other causal agents related to these symptoms. [source] Identification and Molecular Characterization of Viruses Infecting Cucurbits in PakistanJOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2004A. Ali Abstract Cucurbits are grown throughout the North-West Frontier Province of Pakistan as summer and winter crops. Plants having mosaic, mottling, chlorosis and leaf distortion symptoms were frequently found in most of the cucurbit fields during the survey. Using dot immunobinding assay, Cucumber green mottle mosaic virus (CGMMV), Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV) and Papaya ringspot virus (PRSV) were found infecting cucurbits. CGMMV was widespread, infecting 46.9% of the samples tested followed by ZYMV (14.8%), WMV (12.5%) and PRSV (7.8%). Multiple infections were common with 42% of the samples being infected with two viruses and 8% with three viruses. The nucleotide sequences of the coat protein (CP) genes of these four viruses were determined and deduced amino acid sequence comparisons revealed 88.3,99% similarity of the ZYMV-Pak isolate with other isolates of ZYMV reported worldwide. The amino acid sequence identity of Pakistani isolates of WMV, CGMMV and PRSV ranged from 96.8 to 98.4%, 98.1 to 99.4% and 79.3 to 84.2%, respectively, with other isolates reported elsewhere. Little variability was observed in the sequences of WMV and CGMMV. ZYMV-Pak was very close to the USA isolate, and the PRSV-Pak isolate was close to Indian isolates of PRSV possibly reflecting the geographical relationship between these isolates. [source] Tobraviruses,plant pathogens and tools for biotechnologyMOLECULAR PLANT PATHOLOGY, Issue 4 2010STUART A. MACFARLANE SUMMARY The tobraviruses, Tobacco rattle virus (TRV), Pea early-browning virus (PEBV) and Pepper ringspot virus (PepRSV), are positive-strand RNA viruses with rod-shaped virus particles that are transmitted between plants by trichodorid nematodes. As a group, these viruses infect many plant species, with TRV having the widest host range. Recent studies have begun to dissect the interaction of TRV with potato, currently the most commercially important crop disease caused by any of the tobraviruses. As well as being successful plant pathogens, these viruses have become widely used as vectors for expression in plants of nonviral proteins or, more frequently, as initiators of virus-induced gene silencing (VIGS). Precisely why tobraviruses should be so effective as VIGS vectors is not known; however, molecular studies of the mode of action of the tobravirus silencing suppressor protein are shedding some light on this process. [source] About charge-transport mechanisms in mesoporous silicon under adsorption of plant virusesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 7 2009Yuriy Vashpanov Abstract Changes in the electric parameters and the charge-transport mechanism in a mesoporous silicon under adsorption of TORSV (tomato ringspot virus) and GFLV (grapevine fan leaf virus) NEPO-viruses are analyzed. The mechanism influencing the electric characteristics of the mesoporous silicon under adsorption of the plant viruses is related with the changes in parameters of a potential-barrier system due to redistribution of voltages at the silicon structure. The mechanism of charge transport in the mesoporous silicon is more likely connected to the changes in parameters of isotopic heterojunction barriers under small bias voltages, and it can be interpreted as Poole,Frenkel and tunnel conductivity for large bias. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] First report of Tobacco ringspot virus on Sophora microphylla, a native tree of New ZealandPLANT PATHOLOGY, Issue 4 2009L. I. Ward No abstract is available for this article. [source] First detection of Hydrangea ringspot virus in mountain hydrangea in the Czech RepublicPLANT PATHOLOGY, Issue 2 2009J. Mertelik No abstract is available for this article. [source] The competence of four thrips species to transmit and replicate four tospovirusesPLANT PATHOLOGY, Issue 2 2004T. Nagata The tospoviruses Tomato spotted wilt virus (TSWV), Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Chrysanthemum stem necrosis virus (CSNV) are well-known pathogens on tomato in Brazil. The thrips species Frankliniella occidentalis, F. schultzei, Thrips tabaci and T. palmi were studied for their competence to transmit these tospoviruses. Frankliniella occidentalis transmitted all four tospoviruses with different efficiencies. Frankliniella schultzei transmitted TCSV, GRSV and CSNV. Although F. schultzei has been reported as a vector of TSWV, the F. schultzei population in the present study did not transmit the TSWV isolate used. A population of T. tabaci known to transmit Iris yellow spot virus (onion isolate) did not transmit any of the studied tospoviruses, and nor did T. palmi. Replication of these tospoviruses could be demonstrated by ELISA, not only in the thrips species that could transmit them, but also in those that could not. The results strongly suggest that competence to transmit is regulated not only by the initial amount of virus acquired and replication, but also by possible barriers to virus circulation inside the thrip's body. [source] Detection of Prunus necrotic ringspot virus in begonia by RT,PCRPLANT PATHOLOGY, Issue 6 2002N. Verma No abstract is available for this article. [source] Prunus necrotic ringspot virus isolates in stone fruit germplasm accessions and cultivars in IsraelANNALS OF APPLIED BIOLOGY, Issue 2 2004S SPIEGEL Summary Prunus necrotic ringspot virus (PNRSV) was detected in almonds, plum and apricot germplasm accessions and local almond cultivars in Israel. PNRSV was widespread both in wild and cultivated almond trees and uncommon in wild apricots and plums. The possible variation among the PNRSV isolates was initially evaluated by restriction analysis of PCR products representing the CP gene with the endonuclease RsaI and followed by nucleotide sequence analysis of selected isolates. It was concluded that all 13 isolates belong to group PV96, the largest cluster of PNRSV isolates, described previously. Two PNRSV isolates, one from a plum accession and one from an almond cultivar, were found to be distinct members of group PV96 with unique nucleotide modifications not found in other documented isolates of this virus. However, no PNRSV isolate typical to a specific host and/or to the Middle East region could be identified. This study expands the body of data on variability of PNRSV isolates and highlights the importance of assessing the virus status of germplasm collections by applying reliable diagnostic and differentiating methods. [source] Preliminary X-ray data analysis of crystalline hibiscus chlorotic ringspot virusACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009Ao Cheng Hibiscus chlorotic ringspot virus (HCRSV) is a positive-sense monopartite single-stranded RNA virus that belongs to the Carmovirus genus of the Tombusviridae family, which includes carnation mottle virus (CarMV). The HCRSV virion has a 30,nm diameter icosahedral capsid with T = 3 quasi-symmetry containing 180 copies of a 38,kDa coat protein (CP) and encapsidates a full-length 3.9,kb genomic RNA. Authentic virus was harvested from infected host kenaf leaves and was purified by saturated ammonium sulfate precipitation, sucrose density-gradient centrifugation and anion-exchange chromatography. Virus crystals were grown in multiple conditions; one of the crystals diffracted to 3.2,Å resolution and allowed the collection of a partial data set. The crystal belonged to space group R32, with unit-cell parameters a = b = 336.4, c = 798.5,Å. Packing considerations and rotation-function analysis determined that there were three particles per unit cell, all of which have the same orientation and fixed positions, and resulted in tenfold noncrystallography symmetry for real-space averaging. The crystals used for the structure determination of southern bean mosaic virus (SBMV) have nearly identical characteristics. Together, these findings will greatly aid the high-resolution structure determination of HCRSV. [source] | ||||||||||