• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.70-76
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• 1999

KF 116 was TMV resistant tobacco plant and KB 301 was PVY resistant plant transformed with TMV CP gene and PVY CP gene, respectively. These resistant plants were cross-fertilized and the 4 lines of the TMV-PVY resistant plants were selected from F1 hybrid plants. The rate of PVY-resistant plant in these hybrids was 100 percent and that of TMV-resistant plants including delay type was 90-98 percent at 4 weeks after virus inoculation. It was confirmed that the TMV and PVY CP genes were integrated into the genome of hybrid plants by genomic PCR, and Southern blot hybridization. The genome of F1 hybrid plants had one copy and 4 copies of PVY-CP gene and TMV-CP gene, respectively, and CaMV 35S promoters were not methylated, regardless of the difference symptom development to TMV.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.374-379
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• 1995

The cDNA of tobacco mosaic virus-pepper strain (TMV-P) coat protein (CP) genes were introduced into tobacco plants (Nicotiana tabacum cv. Samsun nn) using a binary Ti plasmid vector of Agrobacterium tumefaciens. these cDNAs introduced into tobacco plants were detected by polymerase chain reaction. Symptom development was distinctly suppressed in the transgenic plant introduced buy sense CP cDNA when the plant was inoculated with TMV-P, while in transgenic tobacco plants of antisense CP gene, symptom development was not suppressed as in non-transgenic plants. TMV-P concentration in the sense CP transgenic tobacco plant was decreased to 1/14 of the concentration in non-transgenic plants. Expression of the kanamycin resistance gene of these transgenic plants could be detected in the progeny.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.77-81
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• 1999

Tobacco plants(Nicotiana tabacum cv. NC82) transformed with TMV CP cDNA were self-fertilized until 8th generation (R$_{8}$), and the transgenic plants from 6th to 8th generation were analized for their resistance to tobacco mosaic virus(TMV) and stability of the gene expression. The 6th generation of the plants(R$_{6}$) showed high resistance(81-91 %) to TMV at eight weeks after artificial inoculation with the virus. The transgenic cell line 601 was the most prominant in the expression of resistance. 98 % of the plants showed no symptom without any agronomic phynotepe variation when they were inoculated with the virus in a experimental field. However, 2% of the plants were revealed as delay type of symptom with mild mosaic on a few leaves. The viral resistance in greenhouse tests of the 7th generation (R$_{7}$) was 54-64%, and the number of delay type plants were increased than that of 6th generation plants. In the 8th generation, 81 % of the plants was complete resistant to the virus. The TMV CP cDNA of the transgenic plants of each generation was also confirmed by genomic PCR, and there was no systemic viral multiplication in the resistant plants. It suggests that the viral resistance and gene expression of the transgenic plants might be stable through the generations.ons.s.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.101-106
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• 1996

Tobacco mosaic virus (TMV) tomato strain was isolated from tomato "Seo-Kwang" in Korea. The virion was purified by density gradient centrifugation, and total viral RNA was isolated from the purified particles. Coat protein (CP) cDNA of the virus was synthesized by RT-PCR, and the purified cDNA fragment was subcloned to pBluescript II SK-. The analysis of nucleotide sequence showed that this cDNA was 693 nucleotides long from the insert of clone p1571 and p1572 which contain complete codons of the viral coat protein gene (474 nucleotides) and 3' untranslated region. The nucleotides of coat protein encoding cDNA of the strain were 6 nucleotides less than that of TMV common strain isolated from tobacco plant in Korea. The CP gene showed 70% maximum homology with that of the common strain in the nucleotide level and 86% maximum homology in amino acid level.cid level.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.260-273
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• 2013

The incidence and distribution of Tobacco mosaic virus (TMV) and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP) gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100%) among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each subgroup was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.125.3-126
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• 2003

A near full-length sequence of a new tobamovirus infecting Hibiscus rosa-sinensis L. was determined. The genome consists of 58 nucleotides (nt) 5' UTR, followed by a 4.9 kb ORF which methyl transferase helicase domain (128 kDa), readthrough protein RNA dependent RNA polymerase (RdRp) 185 kDa and a 52 kDa protein. The 128 kDa protein had a maximum homology of 51.4 ％ to TMGMV and amino acids (an) were 54.3 ％ identical to TMV- vulgare strain. The 185 kDa RdRp had a maximum homology of 53.5％ to TMV-Ob and KGMMV-Y and a 59.6％ homology at the an level to CGMMV-SH. The MP gene encodes 282 aa and its theoretical molecular weight is 30.4 kDa. The nt and an sequence identities of MP ranged from 38.8％ to 43.9％ and 30.9％ to 37.9％, respectively. The CP gene encodes 163 residues and with a theoretical molecular weight of 18.2 kDa The (nt) and aa sequences of the CP were 46.9 ％ to 51.6％ and 45.3％ to 57.1％ identical to other tobamoviruses, respectively. The predicted virion origin of assembly (OAS) was located in the CP gene. Phylogenetic trees generated based on the nt and as sequences of RdRp, MP and CP genes indicated that this new virus clustered with subgroup II tobamoviruses. Although the CP ORF of this virus shared a high nt and aa sequence identity with Sunn-hemp mosaic virus (SHMV), Western analysis showed that it is serologically unrelated to SHMV. We propose the name Hibiscus virus S (HVS) for this Singapore isolate. This is the first report on a near full-length sequence of a Tobamovirus that infects hibiscus.

• Proceedings of the Korean Society of Tobacco Science Conference
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• 1997.10a
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• pp.134-152
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• 1997

Plant viruses of tobacco including tobacco mosaic virus (TMV) and potato virus Y (PVY) cause severe economic losses in leaf-tobacco production. Cultural practices do not provide sufficient control against the viruses. Use of valuable resistant cultivars is most recommendable for the control of the viruses. However, conventional breeding programs are not always proper for the development of virus-resistant plants mostly owing to the frequent lack of genetic sources and introduction of their unwanted properties. Therefore, we tried to develop virus-resistant tobacco plants by transforming commercial tobacco cultivars, NC 82 and Burley 21, with coat protein (CP) or replicase (Nlb) genes of TMV and PVY necrosis strain (PVY-VN) with or without untranslated region (UTR) and with or without mutation. Each cDNA was cloned and inserted in plant expression vectors with 1 or 2 CaMV 35S promotors, and introduced into tobacco leaf tissues by Agrobacterium tumefaciens LBA 4404. Plants were regenerated in kanamycin-containing MS media. Regenerated plants were tested for resistance to TMV and PVY In these studies, we could obtain a TMV-resistant transgenic line transformed with TMV CP and 6 genetic lines with PVY-VN cDNAs out of 8 CP and replicase genes. In this presentation, resistance rates, verification of gene introduction in resistant plants, stability of resistance through generations, characteristics of viral multiplication and translocation in resistant plants, and resistance responses relative to inoculum potential and to various PVY strains will be shown. Yield and quality of leaf tobacco of a promising resistant tobacco line will be presented.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.121.2-122
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• 2003

Since the demonstration that the transgenic plants expressing tobacco mosaic virus(TMV) coat protein(CP) gene showed resistance to TMV infection, there have been numerous attempts to produce virus-resistant plant by introducing of a part of or modified viral genome. This study was conducted to investigate the characterization and variability of disease outbreak of transgenic potato(T-potato) with the CP gene of potato leaf roll virus(PLRV) in an isolated field from 2000 to 2002. In the field inspection, incidence of PLRV on T-potato showed only 3.5％, while non-transgenic potato(N-potato) revealed 13.4％. Infection rate of PLRV was considerably low on T-potato with 4.2％ compared to 15.4％ of N-potato in ELISA tests. Those of potato virus M, potato virus Y and potato virus X on both potatoes were not statistically different. Infection of potato virus A was not observed on both potatoes. Incidence of potato late blight caused by Phytopkhora infestans on T-potato and N-potato did not differ each other with 52.7％, and 50.8％, respectively, Mating type of the causal fungus isolated from both potatoes was all Al types. Results indicates that the CP gene of PLRV affects specifically to the virus in the transgenic potato.

• Research in Plant Disease
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• v.9 no.2
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• pp.89-93
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• 2003

An isolate of Tobacco mosaic virus (TMV) was isolated from potato cultivar ‘Chubak’ showing vein clearing and mild mosaic at Namhae in Korea. This isolate, TMV-St, was differentiated from other tobamoviruses based on biological properties, serological relationships and nucleotide sequence analyses of coat protein genes. TMV-St caused typical symptoms on four indicator plants as compared to the tobamovirus of TMV-U1, Pepper mild mottle virus (PMMoV), and Tomato mosaic virus (ToMV), which caused economic losses in Solanaceous vegetables, tomato, pepper, and eggplant. Remarkably, the TMV-St induced distinctly different symptom of systemic chlorotic spots on Chenophodium murale. On C. murale, Gomphorena globosa, and Nic-otiana rustica, the four viruses were classed by the virulence of systemic or local infections. In serological test TMV-St antiserum showed a precipitation line with each other tabamovirus. The CP gene of TMV-St contain 477 nucleotides, and the nucleotides sequence was the most similar to that of TMV-U1.

• The Plant Pathology Journal
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• v.18 no.6
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• pp.323-327
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• 2002

A rod-shaped virus was isolated from pepper showing mild mosic during the winter growing seasons of 2001 and 2002 in Korea. Based on its biological reactions, serological relationships, reverse transcription-poly-merase chain reaction (RT-PCR) using specific primers, and nucleotide sequence analysis of coat protein (CP) gene, the isolated virus was identified as Tobacco mild green mosaic virus (TMGMV) and designated as Korean pepper isolate (TMGMV-KP). Crude sap from infected tissue was mechanically transmitted to various indicator plants, which produced characteristic symptoms of tobamovirus infection. However, no symptom was observed in Gomphorena globosa. In RT-PCR assays with specific primers toy respective detection of TMGMV, Tobacco mosaic virus (TMV), Pepper mild mottle virue (PMMoV), and Tomato mosaic virus (ToMV), a single strong band of about 500 bp in length was produced from the sample used only with TMGMV primers. The amplified DNA was cloned and the nucleotide sequence was determined. Sequence comparisons with the CP gene of other tobamoviruses indicated that TMGMV-KP shared 99.3％ identity with TMGMV Japanese isolate and only 59.1, 58.6, and 58.1％ identity with TMV, PMMoV and ToMV, respectively. This is the first report of TMGMV in Korea.