• The Plant Pathology Journal
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• v.17 no.6
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• pp.390.1-390
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• 2001

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.26-26
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• 2003

Hepatitis E virus (HEV) has been recognized as a major cause of enterically transmitted non-A, non-B hepatitis in many developing countries. The taxonomy of HEV is not clear and the virus remains unclassified. The objective of this study was to optimize conditions and procedures to detect swine HEV in formalin-fixed, paraffin-embedded tissues by nested RT-PCR and compare this detection method with in situ hybridization. (omitted)

• Biomedical Science Letters
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• v.9 no.2
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• pp.99-103
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• 2003

Hantavirus are rodent-borne RNA virus that belongs to the family Bunyaviridae. Those viruses persistently infect a variety of rodents, and are transmitted by aerosols of their urine, feces and saliva. Antibody titers of sera obtained from normal laboratory rodents against hantaviruses were investigated by indirect immunofluorscence antibody technique (IFA), Seroconversion rates of normal laboratory rodents showed higher in rats than that from hamster and mongolian (M). gerbil. Theses rates of normal laboratory rodents also showed higher in titers against puumala virus (PUUV) than in hantaan (HTNV) and seoul virus (SEOV). We are concerned about infections caused by hantaviruses, especially by PUUV, occurred in laboratory rodents.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.394-398
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• 2001

Because of the great concern over the possibility of contamination from the rod-shaped nuclear virus (PRDV) from Japan and white spot virus (WSSV) from Taiwan, most eggs used in Korean shrimp farms are currently obtained from local broodstock. In addition, the screening of imported broodstock for any viral presence at the National Fisheries Research and Development Institute is also mandatory. Nonetheless, massive mortality from white spot syndrome continues in Korea. In the present study, we present an improved PCR method to use tissue-extracted DNA instead of viral DNA extracted from a purified virus based on a sucrose density gradient, and produced results within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected only with PRDV, while Fenneropenaeus chinensis were infected with both PRDV and WSSV. In 1999, PRDV and WSSV were detected in F. chinensis with signs of infection, but not with WSSV alone.

• The Plant Pathology Journal
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• v.30 no.3
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• pp.269-278
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• 2014

Remorins, a family of plant-specific proteins containing a variable N-terminal region and conserved C-terminal domain, play a role in various biotic and abiotic stresses, including host-microbe interactions. However, their functions remain to be completely elucidated, especially for the Arabidopsis thaliana remorin group 4 (AtREM4). To elucidate the role of remorins in Arabidopsis, we first showed that AtREM4s have typical molecular characteristics of the remorins, such as induction by various types of biotic and abiotic stresses, localization in plasma membrane and homo- and hetero-oligomeric interaction. Next, we showed that their loss-of-function mutants displayed reduced susceptibility to geminiviruses, Beet Curly Top Virus and Beet Severe Curly Top Virus, while overexpressors enhanced susceptibility. Moreover, we found that they interacted with SnRK1, which phosphorylated AtREM4.1, and were degraded by the 26S proteasome pathway. These results suggest that AtREM4s may be involved in the SnRK1-mediated signaling pathway and play a role as positive regulators of the cell cycle during geminivirus infection.

• The Plant Pathology Journal
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• v.33 no.4
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• pp.429-433
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• 2017

Chrysanthemums (Chrysanthemum morifolium) are susceptible to tobacco mosaic virus (TMV). TMV-based expression vectors have been used in high-throughput experiments for production of foreign protein in plants and also expressing green fluorescent protein (GFP) to allow visualization of TMV movement. Here, we used TMV expressing the GFP to examine the infection of chrysanthemum by a TMV-based expression vector. Viral replication, movement and GFP expression by TMV-GFP were verified in upper leaves of chrysanthemums up to 73 days post inoculation (dpi) by RT-PCR. Neither wild-type TMV nor TMV-GFP induced symptoms. GFP fluorescence was seen in the larger veins of the inoculated leaf, in the stem above the inoculation site and in petioles of upper leaves, although there was no consistent detection of GFP fluorescence in the lamina of upper leaves under UV. Thus, a TMV-based expression vector can infect chrysanthemum and can be used for the in vivo study of gene functions.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.289-295
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• 2008

RNA-RNA interactions and the dynamic RNA conformations are important regulators in virus replication in several RNA virus systems and may also involved in the regulation of many important virus life cycle phases, including translation, replication, assembly, and switches in these important stages. The 5' non-translated region of Potato virus X(PVX) contains multiple cis-acting elements that facilitate various viral processes. It has previously been proposed that RNA-RNA interactions between various RNA elements present in PVX RNA genome are required for PVX RNA accumulation(Hu et al., 2007; Kim and Hemenway, 1999). This model was based on the potential base-pairing between conserved sequence elements at the upstream of subgenomic RNAs(sgRNAs) and at the 5' and 3' end of RNA genome. We now provide more evidence that RNA-RNA base-pairing between elements present at the 5' end and upstream of each sgRNA is required for efficient replication of genomic and subgenomic plus-strand RNA accumulation. Site-directed mutations introduced at the 5' end of plus-strand RNA replication defective mutant(${\Delta}12$) increasing base-pairing possibility with conserved sequence elements located upstream of each sgRNAs restored genomic and subgenomic plus-strand RNA accumulation and caused symptom development in inoculated Nicotiana benthamiana plants. Serial passage of a deletion mutant(${\Delta}8$) caused more severe symptoms and restored wild type sequences and thus retained possible RNA-RNA base-pairing. Altogether, these results indicate that the RNA element located at the 5' end of PVX genome involved in RNA-RNA interactions and play a key role in high-level accumulation of plus-strand RNA in vivo.

• The Plant Pathology Journal
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• v.22 no.2
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• pp.155-160
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• 2006

A strain of Pepper mottle virus (PepMov) was isolated from chili pepper plants in Korea. In host range study, this virus, designated PepMoV-SNU1, shared most characteristics with PepMoV isolates reported previously. Thermal inactivation point ($45^{\circ}C\;to\;75^{\circ}C$) and dilution end point ($10^{-1}\;to\;10^{-4}$) of PepMoV-SNU1 showed differences depending on the propagation hosts. Cylindrical and pinwheel-shaped inclusions were always observed in pepper leaf tissues infected with the virus alone. Unexpectedly, a special structure of pinwheel shaped inclusion surrounded with unknown small spots was also observed in the leaf section when co-infected with a strain of pepper mild mottle virus. The partial sequence of coat protein gene and 3' untranslated region of PepMoV-SNU1 showed 98% identity with those of other PepMoV isolates. A primer pair derived from 3' end of the coat protein gene and poly A tail regions were designed. Optimal detection condition of PepMoV-SNU1 by RT-PCR was tested to determine appropriate annealing temperature and additional volumes of oligo-dT (18-mer), dNTP, and Taq polymerase. Under the optimized condition, an expected 500 Up PCR-product was detected in pepper leaves infected with PepMoV-SNU1 but not in healthy plants.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.189-195
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• 2020

The soybean (Glycine max L.), also known as the soya bean, is an economically important legume species. Pathogens are always major threats for soybean cultivation. Several pathogens negatively affect soybean production. The soybean is also known as a susceptible host to many viruses. Recently, we carried out systematic analyses to identify viruses infecting soybeans using soybean transcriptome data. Our screening results showed that only few soybean transcriptomes contained virus-associated sequences. In this study, we further carried out bioinformatics analyses using a soybean flower bud transcriptome for virus identification, genome assembly, and single nucleotide variations (SNVs). We assembled the genome of Soybean yellow common mosaic virus (SYCMV) isolate China and revealed two SNVs. Phylogenetic analyses using three viral proteins suggested that SYCMV isolate China is closely related to SYCMV isolates from South Korea. Furthermore, we found that replication and mutation of SYCMV is relatively low, which might be associated with flower bud tissue. The most interesting finding was that SYCMV was not detected in the cytoplasmic male sterility (CMS) line derived from the non-CMS line that was severely infected by SYCMV. In summary, in silico analyses identified SYCMV from the soybean flower bud transcriptome, and a nearly complete genome of SYCMV was successfully assembled. Our results suggest that the low level of virus replication and mutation for SYCMV might be associated with plant tissues. Moreover, we provide the first evidence that male sterility might be used to eliminate viruses in crop plants.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.86-102
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• 1994

To understand the molecular structure and pathogenesis mechanism of Korean garlic viruses, we have isolate cDNA clones for garlic viruses. The partial nucleotide sequences of 24 cDNA clones were determined and that of six clones containing poly (A) tail were compared with those of other plant viruses. One of those clones, V9 has 81.8% similarity in nucleotide sequence and 93.0% in deduced amino acid sequence, respectively, to the coat protein gene for garlic mosaic virus (GMV). Northern blot analysis with the clone V9 demonstrated that the genome of GMV is 7.8 kb long and has poly (A) tail. The anti-coat protein antibody for GMV recognizes 35 kDa polypeptide which could be the coat protein of GMV from infected garlic leaf extract or virus preparation. Clone G7 has about 62% of deduced amino acid sequence identity with the members of potyvirus group. Northern blot analysis with the clone G7 demonstrated that the genome of the potyvirus I garlic is 9.0 kb long and has poly (A) tail. The third clone, S81, shows 42% amino acid identity to the potexvirus. The other clones are under the characterization. To test the possibility of producing garlic virus resistant plant, we have designed a hairpin type ribozyme to cleave V9 RNA at the middle of the coat protein gene. From the cleavage reactions in vitro with two different sizes of RNA substrates, V9SUB (144 nucleotides) and V9 RNA (1,361 nucleotides), the ribozyme can cleave V9 sequence effectively at the predicted site. To study the activity of the ribozyme in vivo, plant transformation is in progress. Further possibilities to produce garlic virus resistant plant will be discussed.