• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.147.1-147
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• 2003

Freesia, a member of the Iridaceae family, has fragant, tubular shaped flowers and is very popular ornamental plants in the world. Diseased freesia plants showing systemic leaf streak mosaic symptoms were collected from a cultivated farm in Kyonggi province, Korea in 2003, and its causal agents were investigated. Two viruses, Cucumber mosaic virus (Fr-CMV) and a potyvirus, were identified from the leaf tissues of the diseased freesia based on sequence analysis and host range tests. CMV-Fr could infect systemically on Chenopodium quinoa, C. amaranticolor, N. glutinosa, and N. benthamiana, and this biological property is distinguishable from ordinary strains of CMV. A filamentous potyvirus-shaped virus could not infect general indicator plants by mechanical inoculation. Single RT-PCR products was successfully amplified with a set of degenerate primers specific to the Potyvirus genus and total nucleic acids from the infected tissues, and was cloned into the pGEMT-Easy vector. Nucleotide sequences confirmed it belongs to the Potyvirus genus with either a new species or an isolate of Freesia mosaic virus (no information is available for the FrMV). This is the first report of FrMV in Korea and more characterizations of the two viruses are in progress.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1074-1078
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• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• The Plant Pathology Journal
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• v.17 no.4
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• pp.201-204
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• 2001

Ultrastructural observation was conducted for the cells of oriental cabbage, Brassica campestris ssp. pekinensis 'Chungawang', inoculated simultaneously with Turnip mosaic virus (TuMV-ACT2-4vq) and Ribgrass mosaic virus (RMV-Ca1dn2) which were known as major destructive viruses of oriental cabbage in Korea. In cells infected with RMV alone, the virus particles were located as bundle or scattering in cytosols and vacuoles, which were typical ultrastructures of tobamovirus. Vessels of xylem were compacted with RMV particles. The cells infected only with TuMV had the cluster of virus particles scarcely and the typical potyvirus inclusions of scrolls, pinwheels, tubes and laminated aggregates in cytosols. The TuMV particles were jammed lineally between tonoplasts. In double infection, the two unrelated viruses of TuMV-ACT2-4vq and RMV-CA1dn2 were located together in a cell, and typical properties of each virus were also observed. The potyvirus inclusions and the tobamovirus particles were mixed entirely in cytoplasm. The virus particles of RMV wre presented strikingly near and in the center of potyvirus inclusions. In vascular cells, the tobamovirus particles were located abundantly than those in single infection. The potyvirus inclusions were embedded in the cluster of RMV particles in phloem parenchyma cells and the vascular elements were degenerated severely.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.243-248
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• 2001

Two Tobamoviruses, Cucumber green mottle mosaic virus (CGMMV) and Zucchini green mottle mosaic virus (ZGMMV), occurred in Korea in 463 ha in 1998, 33.9 ha in 1999, and 44.2 ha in 2000. CGMMV was detected in watermelon, cucumber, oriental melon, and melon, whereas ZGMMV was mainly detected in zucchini squash. Thirty-six CGMMV isolates wee classified into three types by analysis of single strand cDNA conformational polymorphism (SSCP) of the coat protein gene. In a comparison of serological relationships among CGMMV, ZGMMV, and Kyuri green mottle mosaic virus (KGMMV), the three tobamoviruses specifically reacted with each homologous antibody in the double-antibody sandwich enzyme-linked immunosorbent assay and rapid imunofilter paper assay (RIPA), although ZGMMV and KGMMV were slightly biologcially similar. In a survey of the three tobamoviruses in cucurbitgrowing field in Korea by RIPA, CGMMV and ZGMMV were detected but KGMMV was not found in commercially growing cucurbit crops so far. Seed contamination ratio of CGMMV in bottle gourd seeds tested was 84%, while seed trasmission ratio from the virus-contaminated seeds was 2.0%. Soil transmission ratio was 0-3.5% in fields naturally infested with CGMMV or ZGMMV. Control measures of the virus diseases are roguing and sanitation. These suggest that it is important to rogue the first infected crops, which include the seed and soil, especially early in the season. This may be practicable to control the diseases because CGMMV and ZGMMV have a narrow host range restricted to cucurbitaceous crops.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.12-17
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• 2002

For the molecular detection of Sweet potaio feathery mottle virus (SPFMV) from diseased sweet potato plants, reverse transcription and polymerase chain reaction (RT-PCR) was performed with the use of a set of virus-specific primers to amplify an 816 bp product. The viral coat protein gene was selected for the design of the primers. No PCR product was amplified when Turnip mosaic virus, Potato vims Y or Cucumber mosaic virus were used as template in RT-PCR with the SPFMV-specific primers. The lowest concentration of template viral RNA required for detection was 10 fg. The vim was rapidly detected from total nucleic acids of leaves and roots from the virus-infected sweet potato plants as well as from the purified viral RNA by the RT-PCR. Twenty-four sweet potato samples were selected and analyzed by RT-PCR and restriction fragment length polymorphism (RFLP). RFLP analysis of the PCR products showed three restriction patterns, which resulted in some point mutations suggesting the existence of quasi-species for the vims in the infected sweet potato plants.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.407-415
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• 2014

Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop.

• Journal of the Korean Society of Tobacco Science
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• v.1 no.1
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• pp.33-38
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• 1979

A simple test using latex-agglutination was developed to detect serologically tobacco mosaic virus (TMV), soybean mosaic virus (SoyMV), and barley stripe mosaic virus (BSMV) from infected Plants. Latex spheres ( 0.81 $\mu$, Difco) were adsorbed with immuno globulin purified by electrophoresis from crude antiserum against viruses. The antibody- sensitized latex suspension was mixed with sap from virus -infected leaves in a glass capillary tube (inner diam. 1mm $\times$ 100 mm length) The mixture, after agitation, was observed under a stereo microscope at low magnification (X20 - X4O), to examine the reaction between antigen (Virus) and its antibody. Flocculation occurred when the reaction was positive.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.291-296
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• 2011

In order to detect quarantine plant viruses, we developed reverse transcription-polymerase chain reaction (RT-PCR) primer pairs for five single-stranded (ss) plant RNA viruses that are not currently reported in Korea but could be potential harmful plant viral pathogens. Three viruses such as Chilli veinal mottle virus (ChiVMV), Colombian datura virus (CDV), and Tobacco etch virus (TEV) belong to the genus Potyvirus while Chrysanthemum stem necrosis virus (CSNV) and Iris yellow spot virus (IYSV) are members of the genus Tospovirus. To design RT-PCR primers, we used reported gene sequences corresponding to the capsid protein and polyprotein for ChiVMV, CDV, and TEV while using nucleocapsid protein regions for CSNV and IYSV. At least two different primer pairs were designed for each virus. Fifteen out of 16 primer pairs were successfully applied in detection of individual quarantine virus with high specificity and efficiency. Taken together, this study provides a rapid and useful protocol for detection of five quarantine viruses.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.199-209
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• 1998

In order to find antiviral effect against Human immunodeficiency virus(HIV), Herpes simplex virus type I(HSV-1) and II(HSV-2) from herb medicines, publicated 29 paters on anti-viral effect of herbal medicines and a convenient virus-induced cytopathic effect (CEP) inhibition assay was introduced. The major virus on experiment are HIV, Hepatitis B virus and HSV-1,2. Those of other studies showed inhibition of infected virus DNA replication and screening test of herbal medicines. More than 15 extractions were prepared by pure water boiling from herbal medicines, and their toxicity of infected cell and anti-viral activities were evaluated. Among them, the major part of herbal medicines showed cell stability compared with the contrast. Cytotoxic concentration (CC) of the $H_2O$ extracts of Padoo against HIV was <4.0, Hyungbangpaedoksan against HIV was 9.3, Whangyonhaedoktang against HIV-1 and HSV-2 was 15.3. These are high level cytotoxic concentration compared with the contrast. But antiviral effect was unable to figure out for selective $index(SI)=CC_{50}/EC_{50}$. The other herbal medicines were unable to showed potent anti-HIV and anti-HSV activity. The antiviral activation using herbs in this thesis have unlimited objects, to select research object will help to show the direction of antiviral drug development that have less side effect and more excellent efficiency.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.155-160
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• 2003

Grapevine leafroll-associated virus 3(GLRaV-3) is one of the most severe pathogens for viral diseases found in Korea. This study was conducted to establish the virus-free stock production system for the virus disease control. The effects of thermotherapy, merestem culture and chemotheratpy to eliminate the GLRaV-3 in gratevines were tested. Thermotherapy at 37$\pm$2$^{\circ}C$ for 6∼8 weeks combined with 0.5∼1.0mm size of meristem culture method was the most effective for virus elimination. Thermotherapy alone was not effective. In chemotheratpy, DHT and Amantadine (20, 40mg/L) treatment in medium was more effective than Ribavirin to eliminate the GLRaV-3 in grapevine. However, Ribavirin spraying to potted was not available for virus elimination. Therefore, virus-free stock production system using the thermotherapy combined with shoot apical meristem culture was the most effective in grapevine.