• Journal of Plant Biology
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• v.39 no.4
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• pp.265-271
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• 1996

Full-length cDNA for RNA2 of cucumber mosaic virus strian Kor (Kor-CMV) was cloned downstream of synthetic T7 promoter by reverse transcriptase-polymerase chain reaction (RT-PCR). The clone could generate a full-length transcript corresponding to RNA1 in size when synthesized by T7 RNA polymerase. The complete nucleotide sequence has shown that the RNA2 is composed of 3,049 nucleotides and contains one functional open reading frame (ORF) of 2,574 nucleotides encoding 2a protein. The deduced translation product of the 2,574 nucleotides contains GDD motif which is a characteristic of RNA-dependent RNA polymerase (RdRp). The amino acid sequence analysis of the 2a protein has shown that the homology is found in decreasing order with O-CMV (98.8%), Y-CMV (98.7%), Fny-CMV (98.3%), KCMV (94.9%), Ix-CMV (91.9%), and Q-CMV (74.9%). Kor-CMV is suggested to belong to subgroup Ⅰ in the aspect of nucleotide sequence homology of RNA2.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.148.2-149
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• 2003

Cucumber fruit mottle mosaic tobamovirus (CFMMV) causes severe mosaic symptoms with yellow mottling on leaves and fruits, and occasionally severe wilting of cucumber plants. No genetic source of resistance against this virus has been identified. The genes coding for the coat protein or the putative 54-kDa replicase were cloned into binary vectors under control of the SVBV promoter. Agrobacterium-mediated transformation was peformed on cotyledon explants of a parthenocarpic cucumber cultivar with superior competence for transformation. R1 seedlings were evaluated for resistance to CFMMV infection by lack of symptom expression, back inoculation on an alternative host and ELISA. From a total of 14 replicase-containing R1 lines, 8 exhibited immunity, while only 3 resistant lines were found among a total of 9 CP-containing lines. Line 144 homozygous for the 54-kDa replicase was selected for further resistance analysis. Line 144 was immune to CFMMV infection by mechanical and graft inoculation, or by root infection following planting in CFMMV-contaminated soil. Additionally, line 144 showed delay of symptom appearance following infection by other cucurbit-infecting tobamoviruses. Infection of line 144 plants with various potyviruses and cucumber mosaic cucumovirus did not break the resistance to CFMMV. The mechanism of resistance of line 144 appears to be RNA-mediated, however the means is apparently different from the gene silencing phenomenon. Homozygote line 144 cucumber as rootstock demonstrated for the first time protection of a non-transformed scion from soil inoculation with a soil borne pathogen, CFMMV.

• Molecules and Cells
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• v.19 no.2
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• pp.228-231
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• 2005

Recent characterization of several genes involved in plant defense responses suggested that ubiquitin-mediated protein degradation has a role in these responses. We isolated two cDNAs (NtUBA1 and NtUBA2) encoding ubiquitin-activating enzyme (E1) from Nicotiana tabacum cv. BY-2. The open reading frames of both encoded 1080 amino acids, corresponding to molecular masses of 120 kDa. The E1s and corresponding transcripts were upregulated by infection with tobacco mosaic virus (TMV) and tomato mosaic virus (ToMV), and to a lesser extent by cucumber mosaic virus (CMV). Furthermore, they were also upregulated by wounding stress, and the plant hormones salicylic acid, jasmonic acid and the ethylene precursor, aminocyclopropane-1-carboxylic acid (ACC). Our findings support the idea that the ubiquitin-proteasome system plays a role in plant disease defenses.

• BMB Reports
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• v.32 no.1
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• pp.82-85
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• 1999

The movement protein of cucumber mosaic virus (CMV) is required for cell-to-cell movement of viral RNA. The movement of viral RNA occurs through the plant intercellular connection, the plasmodesmata. The viral movement protein was known to be multi-functional. In this work, a series of deletion mutants of CMV movement protein gene were created to identify the functional domains. The mutated movement proteins were produced as inclusion body in E. coli, and purified and renatured. A polyclonal antibody was raised against the CMV-Kor strain (Korean isolate) movement protein expressed in E. coli. The ability of the truncated proteins to bind to ssRNA was assayed by UV cross-linking and gel retardation analyses. The results indicate that the domain between amino acids 118 and 160 of CMV movement protein is essential for ssRNA binding.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.159-161
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• 2003

The coat protein (CP) gene of Apple mosaic virus (ApMV), a member of the genus Ilarvirus, was selected for the design of virus-specific primers for amplification and molecular detection of the virus in cultivated apple. A combined assay of reverse transcription and polymerase chain reaction (RT-PCR) was performed with a single pair of ApMV-specific primers and crude nucleic acid extracts from virus-infected apple for rapid detection of the virus. The PCR product was verified by restriction mapping analysis and by sequence determination. The lowest concentration of template viral RNA required for detection was 100 fg. This indicates that the RT-PCR for detection of the virus is a 10$^3$times more sensitive, reproducible and time-saving method than the enzyme-linked immunosorbent assay. The specificity of the primers was verified using other unrelated viral RNAs. No PCR product was observed when Cucumber mosaic virus (Cucumovirus) or a crude extract of healthy apple was used as a template in RT-PCR with the same primers. The PCR product (669 bp) of the CP gene of the virus was cloned into the plasmid vector and result-ant recombinant (pAPCP1) was selected for molecule of apple transformation to breed virus-resistant transgenic apple plants as the next step. This method can be useful for early stage screening of in vitro plantlet and genetic resources of resistant cultivar of apple plants.

• Journal of Plant Biology
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• v.38 no.3
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• pp.267-274
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• 1995

Based upon the nucleotide sequence of As strain of cucumber mosaic virus (CMV-As0 RNA4, coat protein (CP) gene was selected for the design of oligonucleotide primers of polymerase chain reaction (PCR) for detection and identification of the virus. Reverse transcription and polymerase chain reaction (RT-PCR) was performed with a set of 18-mer CMV CP-specific primers to amplify a 671 bp fragment from crude nucleic acid extracts of virus-infected leaf tissues as well as purified viral RNAs. The minimum concentrations of template viral RNA and crude nucleic acids from infected tobacco tissue required to detect the virus were 1.0 fg and 1:65,536 (w/v), respectively. No PCR product was obtained when potato virus Y-VN RNA or extracts of healthy plants were used as templates in RT-PCR using the same primers. The RT-PCR detected CMV-Y strain as well as CMV-As strain. Restriction analysis of the two individual PCR amplified DNA fragments from CMV-As and CMV-Y strains showed distinct polymorphic patterns. PCR product from CMV-As has a single recognition site for EcoRI and EcoRV, respectively, and the product from CMV-Y has no site for EcoRI or EcoRV but only one site for HindIII. The RT-PCR was able to detect the virus in the tissues of infected pepper, tomato and Chinese cabbage plants.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.265-270
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• 2006

Cultivated hot pepper crops showing severe mosaic symptom were found in Korea in 2004 and their causal agent was identified as Cucumber mosaic virus (CMV). These pepper crops was resistant to the virus in the filled, and they belonged to pathotype 0 (P0) resistant pepper. Resistance screening of selected pepper plants showed that a pepper isolate of CMV was the P0 resistance-breaking virus. This P0 resistance-breaking isolate of CMV, named as Ca-P1, was isolated from leaves of the virus-infected Capsicum annuum cv. Manidda that showed systemic severe mosaic symptom. Ca-P1-CMV could induce systemic mosaic symptoms on P0-susceptible (P0-S) and P0-resistant (P0-R) cultivars whereas an ordinary strain (Fny-CMV) could not infect P0-R. This result suggests that Ca-P1-CMV can overcome P0 resistant pepper cultivars. To analyze its genome sequence, the complete nucleotide sequence of RNA3 of Ca-P1-CMV was determined from the infectious full-length cDNA clone of the virus. RNA3 of Ca-P1-CMV consisted of 2,219 nucleotides. Overall sequence homology of RNA3-encoded two viral proteins (movement protein and coat protein) revealed high similarity (75.2-97.2%) with the known CMV strains. By sequence analysis with known representative strains of CMV, Ca-P1-CMV belongs to a typical member of CMV subgroup IB. The resistance and resistance-breaking mechanisms of pepper and counterpart CMV, respectively, remain to be investigated, which will enrich the genetic resources and accelerate CMV-resistant pepper breeding programs.

• Research in Plant Disease
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• v.15 no.3
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• pp.254-258
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• 2009

An isolate of Cucumber mosaic virus (CMV), called as Lag-CMV, was identified from Lagenaria leucantha var. gourda showing mosaic symptom, and its properties was compared to Fny-CMV (subgroup IA) and As-CMV (subgroup IB) by host reaction in several indicator plants, dsRNA analysis, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein gene. Lag-CMV was similar to As-CMV used as a control CMV by the induced chlorotic spot on inoculated leaves and mosaic symptoms on upper leaves of N. tabacum. cv. Xanthi nc. In the cucumber and zucchini squash, Lag-CMV and As-CMV induced a mild mosaic symptoms than that of Fny-CMV. Size and shapes of local lesions on Chenophodium amaranticolor and Vigna unguiculata induced by Lag-CMV was similar those by Fny-CMV or As-CMV. In experiments of dsRNA profiles and RT-PCR analysis of coat protein gene, Lag-CMV was come within subgroup I CMV. Moreover, restriction enzyme analysis using EcoRI, SalI, MspI, XhoI, and HindIII of the RTPCR products and nucleotide sequence analysis of the coat protein gene showed that Lag-CMV belong to a member of CMV subgroup IB of the same to As-CMV.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.6-11
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• 2002

An isolate of Cucumber mosaic virus (CMV), PaFMl-CMV causing malformation on the fruit of paprika (Capsicum annuum var, grossum) was characterized based on biological reactions, serological relationships, and partial nucleotide sequence analyses. PaFMl-CMV was distinguishable from other isolates of CMYI Mf-(subgroup I) and LS-CMV (subgroup II), in terms of its reactions to some host plants. Polyclonal antibody against PaFMl-CMV showed homologous antigenic relationship with LS-CMV, however, the antibody formed a spur between PaFMl- and Mf-CMV, In the comparison of molecular size of dsRNAs of PaFMl-CMV with Mf- and LS-CMV, PaFMl-CMV had a slightly smaller RNAl and larger RNA2, RNA3, and RNA4. When the CDNA product of PaFMl-CMV coat protein (CP) gene was digested with some restriction enzymes, the fragment pattern was identical with that of LS-CMV The nucleotide and amino acid sequences of PaFMl-CMV CP gene were 99.5% and 98.6% identical with LS-CMV respectively. The data indicate that PaFMl-CMV belongs to subgroup II of CMV, which is the first report in Korea.

• The Plant Pathology Journal
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• v.36 no.1
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• pp.76-86
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• 2020

Cucumber mosaic virus (CMV) is damaging to the growth and quality of lettuce crops in Lanzhou, China. Recently, however, for the first time an isolate of lettuce necrotic yellows virus (LNYV) has been detected in lettuce crops in China, and there is concern that this virus may also pose a threat to lettuce production in China. Consequently, there is a need to develop a rapid and efficient detection method to accurately identify LNYV and CMV infections and help limit their spread. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays were developed to detect the nucleoprotein (N) and coat protein (CP) genes of LNYV and CMV, respectively. RT-LAMP amplification products were visually assessed in reaction tubes separately using green fluorescence and gel electrophoresis. The assays successfully detected both viruses in infected plants without cross reactivity recorded from either CMV or LNYV or four other related plant viruses. Optimum LAMP reactions were conducted in betaine-free media with 6 mM Mg²⁺ at 65℃ for LNYV and 60℃ for 60 min for CMV, respectively. The detection limit was 3.5 pg/ml and 20 fg/ml using RT-LAMP for LNYV and CMV plasmids, respectively. Detection sensitivity for both RT-LAMP assays was greater by a factor of 100 compared to the conventional reverse transcription polymerase chain reaction assays. This rapid, specific, and sensitive technique should be more widely applied due to its low cost and minimal equipment requirements.