• The Plant Pathology Journal
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• v.15 no.4
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• pp.247-250
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• 1999

Wasabies showing mosaic symptoms were collected and extracted for virus purification. Tobacco mosaic virus (TMV) was identified as causal agent by electron microscopy and nucleic acid and coat protein analyses. TMV strains were determined by enzyme-linked immunosorbent assay (ELISA). TMV was identified as W and C strain in wasabi. The results of host reaction indicated that this virus induced local lesions on Nicotiana tabacum cv. Bright Yellow and N. glutinosa, leaf spots on Chenopodium amaranticolor and mosaic symptoms on wasabi. Rot shape virus particles were observed and was about 300 nm in length. About 6.5 kb single RNA molecule was observed from extracted viral RNA sample and 26 KDa coat protein was detected in denatured acrylamide gel. Infection ratio of TMV was 8% for the first cultivation year, but was 22% for the second year when TMV-W antiserum was used. The results of this experiment showed that infection ratios of both TMV-W and TMV-C strains were higher compared to that of TMV-P strain.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.138.1-138
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• 2003

Potato mop-top virus(PMTV) was identified from Solanum tuberosum cv. Gawon showing bright chlorotic mottle symptom in Namwon, Korea. Samples were collected green-house in February, 2003. Electron microscopic examination of negatively stained preparation revealed that PMTV were rigid-rod shaped particles about 100-150, 250-300 nm x 18-20 nm in length. In ultrathin sections of leaf tissue from diseased potato plants, cluster of viruses particles were observed in the cytoplasm. TAS-ELISA determined that the virus was serologically related to PMTV. PMTV produced double ring necrotic local lesion in inoculated leaf of Chenopodium amaranticolor in incubated at 15$^{\circ}C$. The PMTV could be detected with RT-PCR using PMTV detectable primer set designed to amplify about 540 bp of the partial CP gene of PMTV

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.136-139
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• 1994

Turnip mosaic virus (TuMV) was isolated from Rorippa islandica showing mild mosaic symptom in growing field of Chinese cabbage and radish. Identification of the virus was based on host range, transmission by aphids, electron micrograph, serological reaction and hybridization detection. The virus systemically infected on Chenopodium quinoa, Nicotiana clevelandii, N. glutinosa, Brassica rapa, B. campestris subsp. pekinensis and Raphanus sativus, whereas showed local infection on C. amaranticolor, Gomphrena globosa and Tetragonia tetragonoides. The virus was transmitted by aphid (Myzus persicae). The virus particle was filamentous with 720$\times$12 nm in length, and reacted positively with an antiserum of TuMV in agar gel double duffusion test. In slot-blot hybridization using the digoxigenin(DIG)-labeled RNA probe, TuMV-RNA could be detected in sap of R. islandica infected with the virus. This is the first report of a natural infection of that virus on R. islandica.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.148.1-148
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• 2003

Natural virus infection of cultivated Daphe odora plants showing chlorosis and stunting was observed and their causal agent was investigated. An isolate of isometic virus was purified from infected leaf tissues, and it could infect systemic severe mosaic on Chenopodium quinoa and C. amaranticolor. cDNA library was generated from partially purified viral RNAs and oligo dT primer-pSPORTl system, and recombinant clones were selected and their inserts were sequenced randomly. Nucleotide sequences of the virus were analyzed by BLAST, and it was closely related to members of subgroup B in the genus Nepovirus. The sequence analysis suggest that the virus was identified as an isolate of Cycas necrotic stunt virus (CNSV) because it was 89.7 ％ and 94.7 ％ identical to known CNSV for the CP and 3' noncoding region, respecitively. RT-PCR was performed to screen disease incidence of CNSV in Daphe plants, and five out of 10 plants (50 ％) were infected by CNSV This is the first sequence information of CNSV from Daphe plants.

• Research in Plant Disease
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• v.12 no.2
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• pp.91-98
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• 2006

A filtrate powder, designated as KNF2022, produced from culture broth of Acinetobacter sp. KTB3 was tested for their inhibitory effects on Pepper mild mottle virus (PMMoV) infection to Nicotiana glutinosa or N. tabacum cv. Xanthi nc. When 1/100 dilution with distilled water was treated to the plants and PMMoV was inoculated, the inhibition was estimated to be 94.3 and 95.6%, respectively. The same concentrations of KNF2022 inhibited infections of Pepper mottle virus (PepMoV) and Cucumber mosaic virus (CMV) on Chenopodium amaranticolor by 97.1 and 92.5%, respectively. Duration of inhibitory activity of the filtrate powder from Acinetobacter sp. culture broth against PMMoV infection on N. glutinosa was maintained for 2 days at 80% inhibition level, however, the inhibitory effect was diminished from 4 days after treatment to 50% levels. To evaluate inhibitory effects on systemic host plants of the antiviral agent, symptom developments of PMMoV, PepMoV and CMV on KNF2022-treated pepper plants were investigated. Delayed symptom developments until 10 days after inoculation (DAI) were observed for all the three viruses when the viruses were inoculated individually, and these delayed symptom development effects were maintained until 30 DAI in case of PepMoV. Moreover, PepMoV was not detected by RT-PCR and ELISA until 30 DAI. These delayed symptom development effects were diminished in all combinations of three virus co-inoculations due to synergism of three viruses on symptom developments. Inhibitory effect of KNF2022 was verified under electron microscopic examinations using purified virus preparations. Particles of PMMoV and PepMoV were observed on specimens from 5 min after KNF2022 treatment, and the particle sizes were reached in the range of 200-250 nm and 400-600 nm, respectively. Furthermore, the viral particles were destructed and particle sizes were reached in the range of 100-150 nm and 300-500 nm, respectively, on 60 min after treatments. Reduction of local lesion numbers on N. tabacum cv. Xanthi nc and C. amaranticolor were accompanied with reduction of virus particle sizes. In the case of CMV destructed particle numbers were also increased according to incubation period after KNF2022 treatment and local lesions on C. amaranticolor were reduced.

• Research in Plant Disease
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• v.17 no.2
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• pp.211-215
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• 2011

Cucumber mosaic virus (CMV)-like isolate was collected from Raphanus sativus (cv. Choon-hyang), which showed mosaic symptoms. The isolate was confirmed to a strain of CMV by host responses in Vigna unguiculata, Chenopodium amaranticolor and Gomphrena globosa, by viral genome composition with RT-PCR and PCR-RFLP, and by serological analysis. Symptom developed by the strain of CMV was severe in Nicotiana benthamiana, N. glutinosa, N. tabacum (cv. Samsun, cv. Xanthi), Cucumis melo (cv. Early hanover), Cucumis sativus (cv. White wonder), Capsicum annuum (cv. Chung-yang and cv. Geum-top), but mild symptom was developed in Raphanus sativus (cv. Choon-hyang), Brassica rapa ssp. pekinensis (cv. Bul-Am No. 3), and B. juncea (cv. Daenong Jukgot). Newly isolated strain of CMV could infect diverse crops including Solanaceae, Cucurbitaceae and Brassicaceae. We designated the new strain of CMV as Gn-CMV based on the novel infectivity of Brassicaceae. In double-stranded (ds) RNA analysis, Gn-CMV consisted of 3.3, 3.0, and 2.2 kb genomes likewise other strains of CMV. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed 28 kDa of the CMV coat protein. By restriction enzyme mapping using Cac8I, ClaI and MspI of RT-PCR products indicated that Gn-CMV belongs to CMV subgroup I.

• The Plant Pathology Journal
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• v.31 no.4
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• pp.433-437
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• 2015

The infectious full-length cDNA clones of Cucumber green mottle mosaic virus (CGMMV) isolates KW and KOM, which were isolated from watermelon and oriental melon, respectively, were constructed under the control of the cauliflower mosaic virus 35S promoter. We successfully inoculated Nicotiana benthamiana with the cloned CGMMV isolates KW and KOM by Agrobacterium-mediated infiltration. Virulence and symptomatic characteristics of the cloned CGMMV isolates KW and KOM were tested on several indicator plants. No obvious differences between two cloned isolates in disease development were observed on the tested indicator plants. We also determined full genome sequences of the cloned CGMMV isolates KW and KOM. Sequence comparison revealed that only four amino acids (at positions 228, 699, 1212, and 1238 of the replicase protein region) differ between the cloned isolates KW and KOM. A previous study reported that the isolate KOM could not infect Chenopodium amaranticolor, but the cloned KOM induced chlorotic spots on the inoculated leaves. When compared with the previously reported sequence of the original KOM isolate, the cloned KOM contained one amino acid mutation (Ala to Thr) at position 228 of the replicase protein, suggesting that this mutation might be responsible for induction of chlorotic spots on the inoculated leaves of C. amaranticolor.

• 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.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.361-366
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• 1995

A virus was isolated from petunia (Petunia hybrida Vilm.) plants showing chlorotic ring spots on the leaves and color breaking on the flowers, and was identified as petunia asteroid mosaic virus (PAMV). Identification of the PAMV was established by host range test, electron microscopy, serological reaction, and physical properties of the virus. In the host range test, Nicotiana glutinosa, N. rustica, N. clevelandii, P. hybrida, Gomphrena globosa, and Chenopodium amaranticolor were systemically infected with the virus. The virus produced local lesions on inoculated leaves of N. tabacum‘Samsun’, N. tabacum‘Xanthi nc’, Datura stramonium, Vigna unguiculata‘White eye’, C. quinoa, Capsicum annuum, Vicia faba, and Lycopersicon esculentum‘Rutgers’. However, Cucurbita sativus and C. moschata did not show any symptoms. PAMV particles were isometric with 30 nm in diameter. The crude sap from G. globosa infected with the virus reacted positively with antiserum to tomato bushy stunt virus (TBSV) in agar gel double diffusion test. Thermal inactivation point of the virus was 8$0^{\circ}C$ and the virus retained its infectivity at the dilution of 10-4. Longevity in vitro of the virus was estimated longer than 35 days.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.34-37
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• 1999

Cymbidium mosaic virus (CyMV) was purified from CyMV infected orchid plant leaves by Sephacryl S-500 HR column chromatography. Partial purification was done by solubilization with Triton X-100 (alkylphenoxypolyethoxy ethanol) and precipitation with polyethylene glycol (PEG 6,000) followed by ultracentrifugation on 30% sucrose cushion. Based on the spectrophotometric analysis, 33 mg of CyMV could be obtained form 100 g of CyMV-infected orchid plant leaves. The purified CyMV represented one distinct homogeneous band by SDS-PAGE, and electron microscopy revealed that it was highly homogeneous and not fragmented. Bioassay demonstrated that the purified CyMV had a normal infectivity to Chenopodium amaranticolor and orchid plants. Based on these results, the purification method in this work could be served as an improved method for the purification of CyMV and similar viruses with good yield, high purity and native integrity.