• The Plant Pathology Journal
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• v.26 no.1
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• pp.25-31
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• 2010

Papaya ringspot virus (PRSV) causes the most widespread and devastating disease in papaya. Isolates of PRSV originating from different geographical regions in south India were collected and maintained on natural host papaya. The entire coat protein (CP) gene of Papaya ringspot virus-P biotype (PRSV-P) was amplified by RTPCR. The amplicon was inserted into pGEM-T vector, sequenced and sub cloned into a bacterial expression vector pRSET-A using a directional cloning strategy. The PRSV coat protein was over-expressed as a fusion protein in Escherichia coli. SDS-PAGE gel revealed that CP expressed as a ~40 kDa protein. The recombinant coat protein (rCP) fused with 6x His-tag was purified from E.coli using Ni-NTA resin. The antigenicity of the fusion protein was determined by western blot analysis using antibodies raised against purified PRSV. The purified rCP was used as an antigen to produce high titer PRSV specific polyclonal antiserum. The resulting antiserum was used to develop an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) assay and compared its sensitivity levels with ELISA based assays for detection of PRSV isolates. IC-RT-PCR was shown to be the most sensitive test followed by dot-blot immunobinding assay (DBIA) and plate trapped ELISA.

• Journal of Life Science
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• v.9 no.1
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• pp.14-16
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• 1999

Genetic variability was monitored by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) in dicofol-susceptible (S), dicofol-resistant (R) and its reverse-selected (RS) strains of two-spotted spider mite, of Tetranychus urticae. Before the reverse-selection, RS strain, selected reversely from R strain, was 23-fold resistance ratio at {TEX}$LC_{50}${/TEX} to S strain. The resistance was started to in incline slowly to the resistance level of S strain after one year, and the resistance ratio was 4-fold in the 7 years after then. PCR-amplification of T. urticae DNA showed polymorphism in the amplifications with 12 primers in 100 kinds of arbitrary DNA sequences. RAPD amplification with primer OPR-12 (5`-ACAGGTGCGT-3`) showed amplified bands at 1,000 base pair in the S-and RS-strain, and at 350 base pair in R-strain. The results of polymorphism are genetic variabilities derived from development and selection of resistance in each strain. The peculiarly amplified fragments were guessed to participate in dicofol resistance. From the analysis of genetic similarity, it is inferred the gene composition of S-and RS-strain is much closer than that of R-strain.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1057-1062
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• 2016

Kimchi is a traditional Korean fermented vegetable food, the production of which involves brining of Korean cabbage, blending with various other ingredients (red pepper powder, garlic, ginger, salt-pickled seafood, etc.), and fermentation. Recently, kimchi has also become popular in the Western world because of its unique taste and beneficial properties such as antioxidant and antimutagenic activities, which are derived from the various raw materials and secondary metabolites of the fermentative microorganisms used during production. Despite these useful activities, analysis of the microbial community present in kimchi has received relatively little attention. The objective of this study was to evaluate the bacterial community structure from the raw materials, additives, and final kimchi product using the culture-independent method. Specifically, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the 16S rRNA partial sequences of the microflora. One primer set for bacteria, 341F^GC-518R, reliably produced amplicons from kimchi and its raw materials, and these bands were clearly separated on a 35-65% denaturing gradient gel. Overall, 117 16S rRNA fragments were identified by PCR-DGGE analysis. Pediococcus pentosaceus, Leuconostoc citreum, Leuconostoc gelidum, and Leuconostoc mesenteroides were the dominant bacteria in kimchi. The other strains identified were Tetragenococcus, Pseudomonas, Weissella, and uncultured bacterium. Comprehensive analysis of these microorganisms could provide a more detailed understanding of the biologically active components of kimchi and help improve its quality. PCR-DGGE analysis can be successfully applied to a fermented food to detect unculturable or other species.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.71-76
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• 2018

Norovirus is a leading cause of sporadic pathogenic non-bacterial gastroenteritis worldwide. For the detection of norovirus, reverse transcription real-time PCR (RT qPCR) has quickly become a major tool due to its sensitivity and specificity. However, accurate viral RNA extraction methods are essential for RT qPCR analysis. TRIzol reagents are used to extract RNA from biological materials and are therefore widely used for norovirus RNA extraction. In this study, the yield of viral RNA extraction using TRIzol from genogroup II (GII) among the human norovirus genogroup I (GI) and GII, and murine norovirus (GV) depended on the pH of the virus sample solution. The yield of RNA extraction was higher at the alkaline pH than in the acidic region compared with the Ct (threshold cycle) value of the real-time PCR. From the results of this study, it was found that the pH condition is very important for the quantitative analysis of norovirus by extracting GII RNA using TRIzol.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.144-155
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• 1992

A design of a highly stable current-controlled power supply combining the phase-controlled rectifier (PCR), passive filter and active filter is investigated. A digital phase-looked voltage control (PLVC) with a capability of compensating the thyristor firing angles under unvalanced power source is proposed` otherwise the PCR output voltage has low-order subharmonics whose suppression requires a bulky passive filter. The digital PLVC has a fast dynamic characteristics as an inner control loop of the PCR. To suppress further the output ripple, an active filter using a transformer is introduced and its design is described through the frequency domain analysis. An optimal integral, proportional and measurable variable feedback (IPM) controller is designed using the time-weighted performance index based on the time domain analysis. The design method based on the time-weighted performance index gives better response characteristics than that based on the conventional performance index. It is also shown via experimental results that the proposed scheme gives better response characteristics than that based on the conventional performance index. It is also shown via experimental results that the proposed scheme gives good dynamic and static performances.

• KSBB Journal
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• v.8 no.2
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• pp.104-109
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• 1993

A vector for plant transformation which had two reporter genes(Gus and Hpt genes) in a single plasmid was constructed. After rice embryos imbibed DNA solution, DNA uptake and gene expression in rice were monitored. Main expression sites of the Gus gene were meristem of root and coleoptiles. There was no difference in Hpt gene expression between a single Hpt vector and the constructed vector in viability of rice in the hygromycin medium after DNA imbibition, The genomic DNA and total RNA extracted from rice transformant survived in the hygromycin medium were subjected to PCR and RT PCR analysis, respectively. As a result, we found the existence of the Hpt gene and its expression in rice.

• Mycobiology
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• v.30 no.1
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• pp.1-4
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• 2002

Genetic relatedness of medically important Exophiala species such as E. dermatitidis, E. mansonii, and three E. jeanselmei varieties: jeanselmei, lecanii-corni, and heteromorpha was examined using PCR-RFLP(restriction fragment length polymorphism) of ribosomal DNA, M-13, $(GTG)_5$ and nucleotide sequences of ribosomal ITS(internal transcribed space) II regions. Three E. jeanselmei varieties showing distinct band patterns for each DNA markers as well as different nucleotide sequences of ribosomal ITS II regions could be considered as a separate species. E. dermatitidis and E. mansonii demonstrated the identical band patterns of RFLP of ribosomal DNA, M-13, and $(GTG)_5$ markers. However, nucleotides sequences of ribosomal ITS II region were different between these two species.

• Korean Journal of Medicinal Crop Science
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• v.13 no.2
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• pp.121-125
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• 2005

An analysis of RAPD-PCR (random amplified polymorphic DNA-polymerase chain reaction) was performed with three Angelica species (A. gigas Nakai, A. sinensis (Olive.) Diels and A. acutiloba Kitag) in an effort to distinguish between members of these three species. Two arbitrary primers (OPC02, OPD11) out of80 primers tested, produced 17 species-specific fragments among the three species. Eight fragments were specific for A. sinensis, four fragments specific for A. gigas, five specific for A. acutiloba. When primers OPC02 and OPD11 were used in the polymerase chain reaction, RAPD-PCR fragments that were specific for each of the three species were generated simultaneously. Primer OPC02 produced eight species-specific fragments: four were specific for A. sinensis, one for A. gigas, and three for A. acutiloba. Primer OPD11 produced nine speciesspecific fragments: four for A. sinensis, three for A. gigas, and two for A. acutiloba. The RAPD-PCR markers that were generated with these two primers should rapidly identify members of the three Angelica species. The consistency of the identifications made with these species-specific RAPD-PCR markers was demonstrated by the observation that each respective marker was generated from three accessions of each species, all with different origins. We also performed the RAPD-PCR analysis with the dried Angelica root samples that randomly collected from marketed and from the OPC02 primer, obtained a A. gigasspecific band and the band were cloned and sequenced.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.386-393
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• 2017

Onion downy mildew, caused by Peronospora destructor, is a major disease in onion cultivation areas in Korea. The causal fungi were collected and analyzed based on sequence similarity and molecular phylogenetic relationships of multi-gene sequences, including the internal transcribed spacer (ITS) region. All isolates from Changnyeong-gun, Hamyang-gun, and Hapcheon-gun in Gyeongnam province, and Muan-gun, Haenam-gun, and Sinan-gun in Jeonnam province were identical in the four types of gene sequences, indicating they were genetically the same strains. In this study, a PCR method was developed based on the ITS gene sequences to amplify the specific DNA fragment for P. destructor only. The detection limit of was total genomic DNA of the P. destructor and the plant $0.7ng/{\mu}L$. Therefore, the developed PCR method could be used to detect P. destructor effectively from symptomless onion leaves.

• Korean Journal of Medicinal Crop Science
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• v.23 no.6
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• pp.439-445
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• 2015

Background : Correct identification of Panax species is important to ensure food quality, safety, authenticity and health for consumers. This paper describes a high resolution melting (HRM) analysis based method using internal transcribed spacer (ITS) and 5.8S ribosomal DNA barcoding regions as target (Bar-HRM) to obtain barcoding information for the major Panax species and to identify the origin of ginseng plant. Methods and Results : A PCR-based approach, Bar-HRM was developed to discriminate among Panax species. In this study, the ITS1, ITS2, and 5.8S rDNA genes were targeted for testing, since these have been identified as suitable genes for use in the identification of Panax species. The HRM analysis generated cluster patterns that were specific and sensitive enough to detect small sequence differences among the tested Panax species. Conclusion : The results of this study show that the HRM curve analysis of the ITS regions and 5.8S rDNA sequences is a simple, quick, and reproducible method. It can simultaneously identify three Panax species and screen for variants. Thus, ITS1HRM and 5.8SHRM primer sets can be used to distinguish among Panax species.