• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.161-166
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• 1993

A double - stranded cDNA fragment (436bp) encoding coat protein of tobacco mosaic virus(TMV) was derived from the total 480nucleotides gene after reverse transcription of TMV RNA, and subclorled into a plant expression vector pBl 121, resulting in pBL 430. The plasmid DNA containing this chimeric gene was moved from E. cofi to Agrobacterium tumefaciens strain A28l, and was introduced in시 the tobacco plant by the Agrobocterium Ti - mediated transformtion system. The transformants were selected on a selection media containing kanamycin. The shoots add roots could be differentiated from the explants and whole plants were obtained. From Southern blot hybridization analysis, DNA extracted from transformants, it could be conformed that the chimeric gene fragment was inserted into the genomic DNA of tobacco plant.

• Research in Plant Disease
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• v.18 no.4
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• pp.277-289
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• 2012

The total number of requests and associated specimens for the diagnosis of virus infection were 573 and 2,992, respectively, on crops from agricultural places of farmers, Agricultural extension services and so forth for 5 years from 2007. The total number of virus tests was 13,325. The number of species of viruses infected on the submitted crops was 21 in 2007, 15 in 2008, 23 in 2009, 21 in 2010 and 17 in 2011. The newly recorded viruses were Tobacco leaf curl virus (TbLCV) in 2007, Tomato yellow leaf curl virus (TYLCV) in 2008, Impatience necrotic spot virus (INSV) and Radish mosaic virus (RaMV) in 2009, and Beet western yellows virus (BWYV) in 2010. Forty virus species including Alfalfa mosaic virus were detected over 5 years. The ten most frequently detected virus species were Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Tomato leaf curl virus (TYLCV), Cucumber green mottle mosaic virus (CGMMV), Broad bean wilt virus 2 (BBWV2), Zucchini yellow mosaic virus (ZYMV), Melon necrotic spot virus (MNSV), Pepper mild mottle virus (PMMoV), Watermelon mosaic virus (WMV) and Pepper mottle virus (PepMoV). The types of crops submitted from agricultural places were 51 in total and the ten most frequently submitted crops were red pepper, tomato, paprika, watermelon, melon, rice, cucumber, corn, radish and gourd. The total request rate for the top 10 crops and top 20 crops was 81.6% and 94.2%, respectively. Eight pepper infecting virus species included CMV, and the average infection rate was 24.6% for CMV, 18.9% for PMMoV and 14.7% for TSWV. Seven kinds of double infection were detected in pepper including BBWV2+CMV at 14.7% on average, and four types of triple infection including BBWV2+CMV+PepMoV at 0.9% on average. Six virus species detected on tomato including TYLCV, and the average infection rate was 50.6% for TYLCV, 14.5% for TSWV and 10.9% for Tobacco leaf curl virus (TbLCV). The mixed infection of CMV+TSWV on tomato was 3.9% on average and of Tomato mosaic virus (ToMV)+TYLCV was 0.4% on average. Five viruses detected on watermelon included MNSV and the average infection rate was 37.0% for MNSV, 20.4% for CGMMV, 18.1% for ZYMV and 17.8% for WMV. The mixed infection rate on watermelon was CMV+MNSV and WMV+ZYMV having an average infection rate of 0.7% and 5.0%, respectively. The average infection rates on melon were 77.6% for MNSV, 5.6% for CMV and 3.3% for WMV. Mixed infections of CMV+MNSV occurred on melon with an average infection rate of 13.5%.

• The Plant Pathology Journal
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• v.15 no.5
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• pp.295-301
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• 1999

Many of plant defense responses are consequence of transcriptional activation of related genes. We have developed a modified differential screening procedure to isolate tobacco genes that are involved in the defense responses against TMV infection. A cDNA library was constructed from Nicotiana glutinosa leaves infected by TMV under temperature shift conditions. Each of plasmid DNA in the library was hybridized on a set of slot blots to a pool of cDNA probes prepared from either TMV-infected or mock-treated tobacco leaves. Among 900 plasmid DNAs, 81 clones exhibiting significantly enhanced or reduced level of hybridization to either probe were selected for nucleotide sequencing. The clones were listed into 61 genes considering redundancy between the sequences. The genes were identified to be defense-related genes including PR-genes and genes involved in primary or secondary metabolisms. This results supports the implication that plant defense process entails a major shift in total cellular metabolisms rather than activation of a limited number of defense-related genes. Expression patterns of a number of defense-related genes. Expression patterns of a number of selected genes were examined in northern blot analyses. It is notable that the clone 630 of unknown function exhibits expression pattern similar to those of previously known PR-genes. Experiments to elucidate the roles in defense mechanism of a couple of genes newly identified in this study are in progress.

• Research in Plant Disease
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• v.20 no.4
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• pp.307-313
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• 2014

In May 2013, an angel's trumpet leaves showing mosaic and malformation symptoms were collected from Suwon city, Gyeonggi-do. An analysis of the collected sample by transmission electron microscopy observation showed filamentous rod particles of 720-800 nm in length. On the basis of the these observations, we performed PCR against three reported Potyviruses (Brugmansia mosaic virus, Colombian datura virus and Brugmansia suaveolens mottle virus), and the sample was positive for BruMV. Pathogenicity and host range test of BruMV was determined by mechanical inoculation. Solanaceae (tobacco, tomato and eggplant) and Amaranthaceae (ground cherry) appeared typical virus symptoms. To determine coat protein of this virus, we designed specific primer pairs, and performed PCR amplification, cloning, and sequencing. Phylogenetic analysis showed that BruMV-SW was most closely related to BruMV isolate SK. Comparison of the BruMV-SW coat protein nucleotide sequences showed 92% to 99% identities to the other BruMV isolates.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.146.2-147
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• 2003

Two Korean isolates of Alfalfa mosaic virus (AHV-AZ, AMV-KR) were isolated from azuki bean and potato plants, respectively, and their pathologies were confirmed on some susceptible host plants including pepper, tobacco and red bean plants. Full length cDNAs to RNA1, RNA2 and RNA3 of the two Korean strains were amplified using the long-template reverse transcription (RT)-polymerase chain reaction (PCR) method. RT-PCR products covering entire regions for the three AMV genome RNAs were cloned. RNA transcripts were synthesized in vitro from each clones using T7 RNA polymerase and infectivity test was peformed in 9 reassortment sets of transcripts. All the combinations of reassorted transcripts were found to be infectious when inoculated onto Nicotiana benthamiana plants, and were not distinguishable to those of wild types. The full-length cDNA clones that were confirmed infectious were sequenced their nucleotide sequences. We will discuss sequence analysis of the two Korean isolates of AMV genomic RNA3 and compare reported foreign isolates of AMV.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.245-250
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• 1998

Tobacco mosaic virus(TMV) coat protein cDNA was transformed to Nicotiana tabacum cv. NC82 and the transgenic tobacco plants resistant to TMV infection were isolated in the next generation. The expression of TMV coat protein cDNA and genetic stability of the fifth generation of TMV resistant transgenic tobacco plants at the higher temperature were investigated. The TMV coat protein cDNA was amplified by genomic PCR in all the TMV resistant transgenic tobacco plants. The TMV coat protein expressed in the transgenic tobacco plants was detected at very low level by immunoblot hybridization. Even in tansgenic plants that showed the viral symptom only on very late sucker growth (delay type plants), the coat protein expression in the suckers was much less than that of susceptible tobacco infected with TMV. The TMV coat protein expressed in the transgenic tobacco plants was below 0.01% of total protein. Transcription and expression of the coat protein cDNA in delay type plants were observbed at high temperature (38$^{\circ}C$), and TMV replication was suppressed at both 28$^{\circ}C$ and 38$^{\circ}C$. This indicates that unlike the resistance conferred by 'N' gene. TMV resistance of transgenic tobacco plant won't break down at high temperature.

• Korean journal of applied entomology
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• v.15 no.2 s.27
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• pp.61-68
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• 1976

Leading soybean cultivars such as Kwanggyo, Yugu No.3, Dongbugtae, Gangrim, and Eundaedu were heavily diseased by a virus in Korea. The disease was most severe in the northern provinces where soybean mosaic virus also occurrs, but the disease has also been observed in other provinces where soybean diseases are less prevalent. The disease symptoms were similar to bud blight caused by tobacco ringspot virus; but this was not confirmed in inoculation tests on indicator plants and serological experiments. There were some differences in varietal susceptibility to the disease, with symptom variation depending on the soybean cultivar and source of inoculm. Disease symptoms on infected soybean plants were mottling and necrosis. The present results, therefore, indicate some strains of SMV or a mixture of legume viruses may or may not be responsible for the disease.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.280-283
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• 2010

Extracts of 33 medicinal herbs belonging to 28 different families used as precious resources in the Northeast Asia were tested for their antiviral activities against two major plant viruses. Twenty one methanol extracts from 19 different families were found to have a antiviral activity against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) when tested on indicator plants under greenhouse conditions. Most of these extracts have weak activities at the concentration used. But the methanol extracts of Phellinus linteus exhibited potent ($98.7{\pm}1.3%$) antiviral activity against TMV infection and also showed $97.2{\pm}2.2%$ activity against CMV infection. The methanol extracts of the gall of Rhus javanica also showed strong inhibitory efficacy over $98.7{\pm}1.1%$ against TMV or CMV infection. Further research is needed to elucidate the active constituents of these medicinal herbs which may be useful in the development of new and effective antiviral agent against plant viruses.

• Research in Plant Disease
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• v.23 no.4
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• pp.379-382
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• 2017

In March 2016, an isolate of Cucumber mosaic virus (named Gyp-CMV) was isolated from the Sambungai (Gynura procumbens) showing the symptoms of mosaic and chlorosis. The isolate Gyp-CMV was characterized by disease reactions in several indicator plants, reverse transcription-polymerase chain reaction (RT-PCR), PCR-restriction fragment length polymorphism, and sequence analysis of movement protein (3a) and coat protein (CP) genes. Tobacco, tomato, pepper, ground cherry, and lambsquarters (Chenopodium quinoa and C. amaranticolor) appeared typical CMV symptoms, but zucchini and cucumber were not infected. Phylogenetic analysis of the 3a and CP gene indicated that Gyp-CMV belongs to the CMV subgroup II. Sequence identities of the Gyp-CMV 3a and CP genes showed 99.3% and 100% to that of Hnt-CMV at amino acid level. To our knowledge, this is the first report of CMV infection in Gynura procumbens.

• Korean Journal of Microbiology
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• v.12 no.2
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• pp.53-58
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• 1974

A number of antibiotics and organic compounds were tested for their effect on the multoplication of tobacco mosaic virus(TMV) in floating leaf discs. 1)Among six antibiotics tested, kanamycin sulfate showed 24% or more inhibition to TMV multiplication under these experimental conditions. Aureomycin hydrochloride and chloramphenicol showed 19% and 14% inhibition respectively. 2)For screening of organic compounds two environments were used, a diffuse day- light environment (25 foot-candles and laboratory temperature) and an artificial light environment for 12 hours per day(300 foot-candles at 4 to $5^{\circ}C above laboratory temperature). A wide range of organic compounds increased virus multoplication in the diffuse daylight environment but had less effect, or ingibited virus multiplication, in the artificial light environment. 3)The following compounds were among the most effective in increasing TMV multiplication: glucose-1-phosphate, L-aspartic acid, glucose, and 5-bromouracil. The following compoumds were most effective in inhibiting TMT multiplication: thiouracil, uracil, DL-isoleucine, L-leucine, and zinc chloride.