• The Plant Pathology Journal
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• v.34 no.5
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• pp.426-434
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• 2018

During the spring season of 2014, a total of 148 melon and watermelon leaf samples were collected from symptomatic and asymptomatic plants in the western and southwestern regions of Saudi Arabia and were tested for the presence of Watermelon chlorotic stunt virus (WmCSV) and other suspected cucurbit viruses by double antibody sandwich enzyme-linked immunosorbent assays. Ninety-eight samples were found to be positive for the presence of WmCSV, nine samples were positive for the presence of Cucurbit yellow stunting disorder virus (CYSDV), and 22 showed a mixed infection with both WmCSV and CYSDV. No other cucurbit viruses were detected in any of the samples. Host range experiments revealed that eight out of fourteen tested plant species were susceptible to WmCSV. PCR products of approximately 1.2 kb were obtained after amplification using primers specifically targeting the coat protein region of WmCSV. Positive PCR results were confirmed by dot blot hybridization. Coat protein gene sequences from eleven WmCSV isolates indicated that the highest identity was between the 104WMA-SA isolate from the Wadi Baish location and a previously reported isolate from the AL-Lith location in Saudi Arabia. The lowest identity was observed between the 42WMA-SA isolate and an isolate from Palestine.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.115-122
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• 2001

Potato virus X (PVX) is a flexuous rod-shaped virus containing a single plus-strand RNA. Viral RNA synthesis is precisely regulated by regulatory viral sequences and by viral and/or host proteins. RNA sequence element as well as stable RNA stem-loop structure in the 5' end of the genome affect accumulation of genomic RNA and subgenomic RNA (sgRNA). The putative sgRNA promoter regions upstream of the PVX triple gene block (TB) and coat protein (CP) gene were critical for both TB and CP sgRNA accumulation. Mutations that disrupted complementarity between a region at the 5' end of the genomic RNA and the sequences located upstream of each sgRNA initiation site is important for PVX RNA accumulation. Compensatory mutations that restore complementarity restored sgRNA accumulation levels. However, the extent of reductions in RNA levels did not directly correlate with the degree of complementarity, suggesting that the sequences of these elements are also important. Gel-retardation assays showed that the 5' end of the positive-strand RNA formed an RNA-protein complex with cellular proteins, suggesting possible involvement of cellular proteins for PVX replication. Future studies on cellular protein binding to the PVX RNA and their role in virus replication will bring a fresh understanding of PVX RNA replication.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2005.04a
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• pp.53.2-54
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04b
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• pp.145-145
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• 2002

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.66.1-66
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• 2000

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.10a
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• pp.82.1-82
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• 1999

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.101-101
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• 2001

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.384-391
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• 2009

Previously, two events (H15 and B20) of transgenic pepper (Capsicum annuum L.) that enhanced resistance to Cucumber mosaic virus (CMV) by the introduction of CMV coat protein (CP) gene were constructed. Presently, a single copy number of the CP gene was revealed in H15 and B20 by Southern blot. To predict possible unintended effects due to transgene insertion in an endogenous gene, we carried out sequencing of the 5'-flanking region of the CP gene and a Blastbased search. The results revealed that insertion of the transgene into genes encoding putative proteins may occur in the H15 and B20 transgenic event. Mutiplex polymerase chain reaction (PCR) for simultaneous detection and identification of transgenic pepper was conducted with a set of nine primers. Both transgenic event were differentiated from non-transgenic event by the presence of 267 bp and 430 bp PCR products indicative of CP gene specific primer pairs and primer pairs targeting the CP gene and 35S promoter. H15 and B20 uniquely possessed a 390 bp and 596 bp PCR product, respectively. The presence of a 1115 bp product corresponding to intrinsic pepper actin gene confirmed the use of pepper DNA as the PCR template. The primer set and PCR conditions used presently may allow the accurate and simple identification of CMV resistant transgenic pepper.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.150-156
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• 2020

Weeds play an important role in the survival of viruses and are potential inoculum sources of viral diseases for crop plants. In this study, specimens of Pseudostellaria heterophylla exhibiting symptoms of the cucumber mosaic virus (CMV) were collected in Bonghwa, Korea. The characteristics of the disease were described and leaf RNA was extracted and sequenced to identify the virus. Three CMV contigs were obtained and PCR was performed using specific primer pairs. RNA from positive samples exhibiting CMV leaf symptoms was amplified to determine the coat protein. A sequence comparison of the coat protein gene from the CMV BH isolate shared the highest nucleotide identity (99.2%) with the CMV ZM isolate. Phylogenetic analysis showed that CMV-BH belonged to subgroup IA and that the most closely-related isolate was CMV-ZM. All test plants used for the biological assay were successfully infected with CMV and exhibited CMV disease symptoms such as blistering, mosaic, and vein yellowing. To our knowledge, this is the first report of CMV infection in P. heterophylla from Korea.

• The Plant Pathology Journal
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• v.18 no.6
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• pp.317-322
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• 2002

An isolate of Odontoglossum ringspot virus (ORSV) was identified from Cymbidium var. 'Grace Kelly' showing ringspot symptom on the floral and leaf parts, and was denoted as cymbidium ringspot isolate (ORSV-CR). In ultrathin sections of leaf tissue from diseased Cymbidium plants, clusters of virus particles were observed in the vacuole and cytoplasm. In the Western blot hybridization, the virus strongly reacted with ORSV-specific antiserum indistinguishable from ORSV, suggesting that the vims is serologically identical with ORSV. ORSV-CR sap was inoculated onto 20 species belonging to 12 genera. Systemic infection occurred in Cymbidium sp., Nicotiana benthamiana and N. clevelandii, the host of which was found to be different from that of ORSV-Cy, the Korean strain of ORSV. The analysis of coat protein (CP) gene showed that ORSV-CR was highly homologous to the known isolates of ORSV, with over 95.6% identity in amino acid level. Phylogenetic tree analysis of CP showed that ORSV-CR was clustered with the known ORSV isolates, suggesting that ORSV is a very stable tobamovirus.