• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.118.1-118
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• 2002

• The Plant Pathology Journal
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• v.17 no.6
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• pp.388.2-388
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• 2001

• The Plant Pathology Journal
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• v.20 no.2
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• pp.135-141
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• 2004

A filamentous virus was isolated from taro (Colocasia esculenta Schott) showing mosaic and chlorotic feather-ing symptoms in Chuncheon, Gangwon province in 2002. Based on ELISA, its appearance in electron microscope, serological relationships, and RT-PCR using specific primer and nucleotide sequence analysis of the CP gene, the isolated virus was identified as Dasheen mosaic virus (DsMV) and designated as Korean isolated (DsMV-Kr). DsMV was not serologically related to Zantedeschia mosaic virus (ZaMV), which has been reported to infect an Araceae plants. Since the coat protein revealed electrophoretic heterogeneity, about 42 kDa, 39 kDa and 31 kDa by SDS-PAGE, an improved purification method was established for the production of antisera against DsMV-Kr. The purification method used in this study may be effectively applied to the purification of other filamentous viruses.

• 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.

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.193-201
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• 2011

An attenuated vaccine strain AVR1/08 of Korean respiratory type of infectious bronchitis virus (IBV) was developed by 89th passages of IBV D85/06 strain in chicken eggs. The AVR1/08 strain had higher virus titer at least 20 times ($10^{1.3}$) than the parent virus D85/06 by egg inoculation method. The AVR1/08 strain had a single point mutation (S to Y) at position 56 of spike protein of IBV compared to parent virus IBV D85/06 strain. The mutation was observed consistently at viruses after 47th passage in chicken eggs. The AVR1/08 strain showed no virulence even after 6 passages in chickens and all chickens inoculated induced anti-IBV antibody 14 days after vaccination. The AVR1/08 strain had broad protective efficacy against QX type Korean nephropathogenic virus (Q43/06 strain), KM91 type Korean nephropathogenic virus (KM91 strain) and Korean respiratory virus (D85/06 strain). In contrast, Massachusetts (Mass) type attenuated vaccine strain H120 showed protection of 37.5 to 50% against these three viruses. Our results indicate that the AVR1/08 strain has potential as an attenuated vaccine effective in controlling IBVs circulating in Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.110.2-111
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• 2002

• 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.

• The Plant Pathology Journal
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• v.40 no.4
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• pp.377-389
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• 2024

The possibility of new viruses emerging in various regions worldwide has increased due to a combination of factors, including climate change and the expansion of international trading. Plant viruses spread through various transmission routes, encompassing well-known avenues such as pollen, seeds, and insects. However, research on potential transmission routes beyond these known mechanisms has remained limited. To address this gap, this study employed metatranscriptomic analysis to ascertain the presence of plant viruses in imported frozen fruits, specifically cherries and blueberries. This analysis aimed to identify pathways through which plant viruses may be introduced into countries. Virome analysis revealed the presence of six species of plant viruses in frozen cherries and blueberries: cherry virus A (CVA), prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), prunus virus F (PrVF), blueberry shock virus (BlShV), and blueberry latent virus (BlLV). Identifying these potential transmission routes is crucial for effectively managing and preventing the spread of plant viruses and crop protection. This study highlights the importance of robust quality control measures and monitoring systems for frozen fruits, emphasizing the need for proactive measures to mitigate the risk associated with the potential spread of plant viruses.

• 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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.144.2-145
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• 2003

This study was performed to investigate the incidence of Hosta uirus X (HVX), a Potexvirus, from cultivated hosta ornamental plants in Korea and to ascertain seed transmission of the virus from infected parent plant to progeny ones for breeding program of hosta plants. Infection rate of HVX in cultivated hostas was 25.6 ％ (11 out of 43 collected samples contained HVX) based on Western blot and RT-PCR detection methods. Most of HVX-infected hostas showed visible systemic leaf symptoms (mosaic, mottle, curling, stunting or combinations). Variability of HVX was confirmed by sequences of coat protein gene of individual isolates from different hostas. HVX was seed-transmitted on Hosta 'Blue Cadet'. The virus was detected from seeds, and sprouts and seedlings from the virus-contaminated seed sources. Over 7.5 ％ of seeds were HVX-contaminated surveyed in this study, Our data suggest that HVX can be transmitted by seed source, and indexing of the virus should be done for breeding program of Hosta.