• Journal of Life Science
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• v.25 no.10
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• pp.1091-1097
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• 2015

We have isolated and characterized an ascorbate peroxidase (APx) gene, OsAPx1 from rice. Northern and Western blot analyses indicated that at young seedling stage, OsAPx1 mRNA was expressed highly in root, shoot apical meristem (SAM) and leaf sheath than leaf. In mature plant, OsAPx1 gene expressed highly in root, stem and flower but weakly in leaf. OsAPx1 gene and protein expression level was induced in leaves inoculated with Magnaporthe oryzae (M. oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Phytohormones treatment showed that OsAPx1 was up-regulated by jasmonic acid (JA), but was down regulated by ABA and SA co-treatments with JA, resulting that they have antagonistic effect on pathogen responsive OsAPx1 expression. Phylogenetic analysis illustrated that Arabidopsis AtAPx1 has a close relationship with OsAPx1. In AtAPx1 knock out lines, the accumulation of O₂^- and H₂O₂ are all highly detected than wild type, revealing that the high concentration of exogenous H₂O₂ cause the intercellular superoxide anion and hydrogen peroxide accumulation in AtAPx1 knockout plant. These results suggested that OsAPx1 gene may be associated with the pathogen defense cascades as the mediator for balancing redox state by acting ROS scavenger and is associated with response to the pathogen defense via Jasmonic acid signaling pathway.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.305-313
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• 2016

Brassica juncea (2n = 4x = 36, AABB genome, 1,068 Mb) is a U's triangle species and an amphidiploid derivative of B. rapa and B. nigra. Fifteen varieties were used to study the ITS (internal transcribed spacer) regions of ribosomal DNA and MITEs (miniature inverted-repeat transposable elements) with a view of developing specific molecular markers. ITSs and MITEs are an excellent resource for developing DNA markers for genomics and evolutionary studies because most of them are stably inherited and present in high copy numbers. The ITS (ITS1 and ITS2) sequence was compared with the consensus sequence of B. rapa and B. nigra. Variation in ITS1 created two separate groups among 15 varieties, with 10 varieties in one group and 5 in the other. Phylogenetic analysis revealed two major clusters for those 10 and 5 varieties. Among the 160 different MITE primers used to evaluate the selected 15 varieties of B. juncea, 70 were related to the Stowaway, 79 to the Tourist, 6 to the hAT, and 5 to the Mutator super-families of MITEs. Of 160 markers examined, 32 were found to be polymorphic when fifteen different varieties of B. juncea were evaluated. The variety 'Blackgat' was different from the other mustard varieties with respect to both phenotype and genotype. The diversity of 47 additional accessions could be verified using eight selected molecular markers derived from MITE family sequences. The polymorphic markers identified in this study can be used for varietal classification, variety protection, and other breeding purposes.

• Journal of Life Science
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• v.18 no.10
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• pp.1442-1446
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• 2008

Seven populations of 586 Hanwoo have been characterized by using 10 microsatellite DNA markers. Size of microsatellite markers decided using GeneMapper Software (v.4.0) after analyze in kinds of ABI machine of name of 3130. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. Genetic distancesbetween populations were obtained using Ne's DA distance method. Expected heterozygosity between each population was estimated very analogously. Genetic distances (0.0413) between Kangwan (KW) and Gyonggi (GG), Jeonpuk (JP) were nearest than distances between other populations by 0.021. Genetic distances between Gyonggi (GG) and Kyongpuk (KP) showed far distance than other populations by 0.032. In the UPGMA tree that is made based on DA distance matrix. Each individuals were not ramified to different group and were spread evenly in phylogenetic dendrogram about all Hanwoo of each regional area populations. But Hanwoo proven population was ramified to different group.

• Journal of Life Science
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• v.26 no.11
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• pp.1237-1244
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• 2016

A comprehensive analysis of the genetic diversity and relationship of the cold-water fishery walleye pollock (Theragra chalcogramma), the most abundant economically important fishery resource in the East sea of Korea, has not been carried out, despite its importance in Korea. The present study assessed the genetic diversity and relationship between five walleye pollock populations (Korean population, Russian population, USA population, and Japanese populations) of T. chalcogramma using eight microsatellite DNA (msDNA) markers to provide the scientific data for the preservation and management of the Pollock fishery resource. The results of the analysis of 186 individuals of the Pollock revealed a range of 7.13-10.63 numbers of alleles (mean number of alleles=9.05). The means of observed heterozygosity ($H_O$), expected heterozygosity ($H_E$) were 0.732 and 0.698, respectively. The results of genetic distance, Pairwise $F_{ST}$, UPGMA (UPGMA: un-weighted pair-group method with an arithmetical average) (the phylogenetic tree), PCA (PCA: Principal Coordinate analysis) analysis pointed to significant differences between the Korean population, Russian population, USA population, and Japanese populations, although small (p<0.05). These results shed light on the genetic diversity and relationships of T. chalcogramma and can be utilized for research on the evaluation and conservation of Korean T. chalcogramma as genetic resources.

• Korean Journal of Poultry Science
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• v.35 no.4
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• pp.361-366
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• 2009

The purpose of this study was to assess the genetic variation and establish the relationship amongst breeds and strains using 7 chicken specific microsatellite markers. A total of 317 DNA samples from four Korean native chicken (KNC) strains (KR: Korean Native Red chicken strain, KY: Korean Native Yellow chicken strain, KL: Korean Native Black chicken strain, KO: Ogol chicken strain) and three introduced endemic chicken breeds (LE: Leghorn chicken breed, RI: Rhode Island Red chicken breed, CO: Cornish chicken breed). The size of microsatellite markers was decided using GeneMapper Software (v.4.0) after being analyzed using an ABI 3130 Genetic Analyzer. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The lowest distance (0.074) was observed between the KY and KL breeds and the highest distance (0.779) between the KL and LE breeds. The KNC strains (KR, KY, KL) have comparatively near genetic distance each other. On the other side, each individual was not ramified to different groups and were spread evenly in phylogenetic dendrogram about all the KNC of each strain populations. But the endemic breed populations (LE, RI, CO) were ramified to different groups. The microsatellite polymorphism data were shown to be useful for assessing the genetic relationship between Korean native strains and other foreign breeds.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.58-63
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• 2013

A taxonomic study was carried out to assess the phylogenetic characteristics of isolate JJM57 from marine red algae Laurencia sp. collected from intertidal zone in Jeju Island, South Korea. Comparative analysis of 16S rRNA gene sequence shows that this isolate belongs to the genus Oceanisphaera. It shows 98.02% and 97.7% sequence similarity with Oceanisphera litoralis DSM $15406^T$ and Oceanisphera donghaensis KCTC $12522^T$, respectively. Strain JJM57 is a Gram-negative, aerobic, moderately halophilic bacterium able to grow in different NaCl concentration ranges from 0.5 to 8.0% and at varying temperatures from 4 to $37^{\circ}C$. Sharing some of the physiological and biochemical properties with O. litoralis and O. donghaensis, JJM57 strain differs in the utilization of ethanol, proline, and alanine. The G+C contents of the strain JJM57 is 61.94 mol% and it is rich in $C_{16:1}$ ${\omega}7c$ and/or iso-$C_{15:0}$ 2-OH, $C_{16:0}$, and $C_{18:1}$ ${\omega}7c$ fatty acids. The DNA-DNA relatedness data separates the strain JJM57 from other species such as O. litoralis and O. donghaensis. On the basis of these polyphasic evidences, present study proposed that strain JJM57 (=KCTC 22371 =AM983543 =CCUG 60764) represents a novel bacterial species of Oceanisphaera.

• Korean journal of applied entomology
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• v.50 no.2
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• pp.157-165
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• 2011

Enterobacteria were isolated in the gut of the predacious multicolored Asian ladybird beetle, Harmonia axyridis, and their effects to the development of H. axyridis were examined. Populations of H. axyridis in this experiment were collected from Kimjae at Cheonbuk province (JK population), Geumsan at Chungnam province (CK population) and laboratory population at Laboratory of Insect Physiology in Chungnam National University, Daejeon. Thirty-four enterobacteria isolates were purified and isolated from the digestive tract of H. axyridis, and a total of 4 strains were classified into group by analysis of 16S rRNA gene sequences. About 70% of total isolates were phylogenetic groups of Bacillus genus and Staphylococcus genus, and they were commonly separated from the digestive tract of H. axyridis. After investigating their susceptibility against antibiotics with 18 representative enterobacteria isolates, ofloxacin and penicillin were selected for examination in this study of their ability to inhibit the growth of all of isolates. In order to remove the enterobacteria from the aphids, ofloxacin and penicillin were given to the green peach aphid, Myzus persicae, and the turnip aphid, Lipaphis erysimi. These aphids were provided to H. axyridis as prey. The weight of pupa, developmental periods of each larval instar, the number of eggs and their hatching ratio of H. axyridis with treatment aphids were lower compared with non-treatment aphids. Staphylococcus saprophyticus is a representative enterobacteria and commonly isolated from the digestive tract of H. axyridis. In the absence of S. saprophyticus, the developmental periods of each larval instar increased; however, the weights of pupa, the number of eggs, and their hatching ratio decreased.

• Development and Reproduction
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• v.14 no.4
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• pp.269-279
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• 2010

Some characteristics of germ cell differntiations and the function of accessory cells during spermatogenesis, and mature sperm ultrastructure in male Protothaca (N.) jedoensis were investigated by transmission electron microscope observations. The morphology of the spermatozoa of this species has a primitive type and is similar to those of other species in the subclass Heterodonta. Accessory cells, which are connected to adjacent germ cells, are involved in the supplying of the nutrients for germ cell development. The morphologies of the sperm nucleus and the acrosome of this species are the cylindrical type and cap shape, respectively. Spermatozoa are approximately $46{\sim}50{\mu}m$ in length including a long sperm nucleus (about $2.44{\mu}m$ in length), an acrosome (about $0.45{\mu}m$ in length), and tail flagellum (about $42{\sim}46{\mu}m$). The axoneme of the sperm tail shows a 9+2 structure. As some characteristics of the acrosomal vesicle structures, the basal and lateral parts of basal rings show electron opaque part (region), while the anterior apex part of the acrosomal vesicle shows electron lucent part (region). These characteristics of the acrosomal vesicle were found in the family Veneridae and other several families in the subclass Heterodonta. These common characteristics of the acrosomal vesicle in the subclass Heterodonta can be used for phylogenetic and systematic analysis as a taxonomic key or a significant tool. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appear in most species in the family Veneridae and other families in the subclass Heterodonta. However, exceptionally, only three species in Veneridae of the subclass Heterodonta contain 5 mitochondria. The number of mitochondria in the sperm midpiece can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or an important tool.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.380-387
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• 2016

This study was performed to select potentially available biological control agent from soil bacteria for prevention of ginseng damping off. More than five hundred strains were isolated from ginseng rhizosphere soil. By testing antifungal activity, we have selected three soil bacteria strains and their ability to produce antibiotics and lytic enzymes such as cellulase, protease and pectate lyase was examined. Also, the presence of genes for biosynthesis of lipopeptide such as fengycin, bacillomycin D, surfactin, iturin A, and zwittermicin A was investigated in selected strains. All three strains produced cellulase, protease, and xylanase. Moreover, these strains had gene for biosynthesis of bacillomycin D, surfactin, and iturin A. ES1 and ES3 strains were identified Bacillus methylotrophucus and ES2 was confirmed Bacillus amyloliquefaciens using phylogenetic analysis on the basis of 16S rRNA gene sequences. In field test, control value of ES1, ES2 and ES3 treatment was 32.4%, 46.8% and 36.7%, respectively. This results indicate that antagonistic microbes with high ability of antifungal and lytic enzyme activity can be used as a useful biological control agent to control ginseng damping off.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.298-308
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• 2009

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing as green mosaic and puckering symptoms at Anseong, Korea. Based on the biological analysis, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the virus isolate was identified as Papaya ringspot virus type watermelon (PRSV-W). From biological analysis, the host range of PRSV-W was limited to the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucumis lanatus, Cucumis sativus, Cucurbita pepo, and Citrullus lanatus, showed symptoms of green mosaic, malformation, puckering, and narrow laminae by infection with PRSV-W. The local lesion were showed on the inoculated leaves of both Chenopodium amaranticolor and C. quinoa. Field survey of PRSV, Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV), three major viruses infecting cucurbit, was done during 2001 to 2003 on 173 commercial cucurbit cultivating fields distributed over the three regions of Gyeonggi, Gyeongbuk and Jeonnam Provinces where cucurbits are grown in different environmental conditions and cropping patterns. Typical viral symptoms were observed from 107 cultivating fields, and all three kinds of potyviruses were detected from 206 samples out of the 235 samples using RT-PCR. Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) are the most widely distributed viruses in outdoor and retarding-culture fields, at an infection rating of 48 and 33 percents, respectively. PRSV was detected from 12 percent of 235 samples. The nucleotide and amino acid sequences of coat proteins (CP) of eight PRSV isolates, collected from several areas including Anseong, were determined and sequenced heterogeneity among the isolates was performed. The CP gene of PRSV showed 88.6~97.3 percent homology in nucleotide sequences and 95.1~99.3 percent homology in amino acid sequences with other PRSV isolates worldwide. The phylogenetic analysis indicated that the Korean PRSV isolates belong to the southern-east Asian cluster.