• The Korean Journal of Mycology
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• v.23 no.3 s.74
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• pp.246-256
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• 1995

Phenotypic characteristics, pathogenicity and fungicides resistance of fifty one isolates of Botrytis cinerea obtained from various host plants were observed and determined. The relationships between these characteristics were also investigated on the basis of isolation host plants. The isolates of B. cinerea varied in the capacity of sclerotia formation and sporulation. The pathogenicity of 44 isolates from tomato, cucumber, and strawberry was significantly stronger with 3.2 cm in average diameter of necrotic lesions on cucumber leaves than that of seven isolates from other host plants such as orange, gerbera, ginseng, kiwi, grape, pear and from butter with 1.8 cm in average diameter of necrotic lesions. Benomyl resistance of 12 isolates from tomato plants was much higher with the $EC_{50}$, 562 ppm than that of 19 isolates from various host plants. Diethofencarb resistance, however, of 11 isolates from strawberry plants was highest with the $EC_{50}$, 210 ppm among isolates from other host plants. Polygalacturonase activity varied among isolates in the range of 0 to 103 unit and that of isolates from tomato, cucumber and strawberry was slightly lower than that of isolates from other host plants. No significant relationship between pathogenicity and fungicides resistance, polygalacturonase activity was found among 51 isolates of B. cinerea. Isozyme patterns of polygalacturonase produced from two strongly and weakly pathogenic isolates (FC122, KC6) were slightly different depending upon carbon sources during cultivation.

• Molecules and Cells
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• v.39 no.5
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• pp.426-438
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• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.118-125
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• 2013

Antibiotic susceptibility was examined for 596 Salmonella isolates from patients with acute gastroenteritis during 2000-2009 in Gwangju area in South Korea. Of 16 antibiotics tested, ampicillin resistance (43%) was the most commonly observed resistance among the 596 Salmonella sp. isolates, followed by tetracycline (35.9%), nalidixic acid (31.5%), and chloramphenicol (26.2%). Antibiotic resistance varied among serotypes: The highest resistance of S. Enteritidis and S. Typhimurium was to ampicillin (51.1%) and tetracycline (77.9%), respectively. A total of 89 resistance patterns were observed, and 26% (155/596) of Salmonella isolates were susceptible to all antibiotics tested in this study. About 21% (127/596) and 15% (87/596) of the isolates were resistant to one and two antibiotics, respectively. The rest of Salmonella isolates (227/596, 38%) were resistant to three or more antibiotic agents. The highest multi-drug resistance (MDR) was observed in serotype S. Paratyphi B (76.5%), followed by S. Typhimurium (58.2%), and S. Enteritidis (40.2%). The most common resistance pattern of MDR isolates was ampicillin-chloramphenicol-nalidixic acid-ticarcillin (36/227, 15.8%), most of which (35/36, 97.2%) were S. Enteritidis.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.98-104
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• 2015

BACKGROUND: ${\gamma}$-Oryzanol, a mixture of ferulic acid esters of triterpene alcohols and sterols, are a nutritionally important group of rice secondary metabolites. The ${\gamma}$-Oryzanol content and composition were found to vary with enviromental factors such as growth temperature, varietal origin, and cultivation method. Therefore, the effect of green manure treatments will be also be an important factor in their content. METHODS AND RESULTS: The ${\gamma}$-Oryzanols extracted using dichloromethane/methanol were analyzed equipped liquid chromatography with a diode array detector. A total of ten components of ${\gamma}$-oryzanol including ${\Delta}7$-stigmastenyl ferulate were isolated of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components in Korean rice variety, Unkwang. The ${\gamma}$-oryzanol content in rice, in the presence of nitrogen fertilization using green manure was similar to conventional nitrogen fertilization, but was higher than the control(no fertilizations). The ${\gamma}$-oryzanol ontent in rice, in the presence of hairy vetch as green manure crop was the highest compared to other crops (opium-poppy, crimson clover, cornflower). As a result of PLS-DA using SIMCA 11.0 ver. as multivariate analysis program on the basis of total data, in all samples, the specific pattern and cluster of ${\gamma}$-oryzanol scores according to green manure crops and conditions were confirmed with possible distinguishing nitrogen effects. CONCLUSION: The nitrogen contained in the green manure crops is considered to play a major role in the formation of ${\gamma}$-oryzanol. Hairy vetch which contains higher nitrogen increased the concentration of ${\gamma}$-oryzanol in rice.

• Journal of Life Science
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• v.22 no.2
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• pp.177-183
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• 2012

Bacterial wilt (brown rot) caused by Ralstonia solanacearum (Rs) is one of the most devastating bacterial plant diseases in potatoes. To isolate bacterial wilt disease resistance-related genes from the potato, the StACRE (HM749652) gene was isolated and a sequenced search was performed using functional orthologs of Solanaceae from potatoes. StACRE is homologous to the tobacco NtACRE 132 protein and belongs to the ATL family involved in ubiquitination. To analyze the expression pattern of this gene, RT-PCR was performed with potato treated with salicylic acid (SA) and Rs (KACC 10722). StACRE was strongly induced 3 hours after treatment with SA and 12 hours after infection with Rs. To investigate its biological functions in the potato, we constructed a vector for overexpression in the potato by the Gateway system, and then generated transgenic potato plants. The gene expression of transgenic potato was analyzed by northern blot analysis. In the results of disease resistance assay in relation to bacterial wilt, StACRE overexpressed transgenic potato plants were shown to have more resistance than wild-type potato.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.15-22
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• 1988

Factors affecting the regeneration, reversion of protoplasts from mycelium of F. velutipes were investigated and the selection of auxotrophic mutants from protoplasts of F. velutipes was performed. PDP medium stabilized with 0.6M sucrose was suitable for the regeneration of protoplasts, and regeneration frequency was 0.47-1.32. The regeneration frequency of protoplasts was increased when nutrients were added to the regeneration medium. Especially, yeast extract was the most effective to regeneration of protoplasts. Regeneration pattern of protoplasts was formation of germ tubes from bud-like cells. 13-18% of monokaryotic strains was appeared from reverted protoplasts. Five of auxotrophic mutants were isolated from strains showed survival frequency of 1.9-16.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.231-237
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• 1981

In order to obtain the basical data for utilization of protein in hazel nut, protein was extracted from defatted hazel nut meal with salt solutions and alkaline solutions, and precipitated by adjusting pH of extract to 5.5 or addition of organic solvents. Amino acid composition of the isolated protein and defatted hazel nut meal were analyzed, protein isolates were identified by polyacrylamide gel electrophoresis. The results summarized were as follows. 1. Defatted hazel nut showed highly nutritional value as the content of 'protein was 53.6%. 2. Extractabilities of salt-soluble protein treated with 2.5M $MgCl_2$, and 1M NaCl(pH 11.0) were 53.0%, 31.5%, respectively 3. Protein in hazel nut were contained 53% of salt-soluble globulin, 14% of water-soluble albumin, 29.5% of glutelin based on solubility. 4. At pH 5.5, 85% of the extracted protein was precipitated, and about 90% of the extracted protein was separated by addition of organic solvents such as acetone and ethanol at 60-70% concentration. 5. Proteins extracted from defatted hazel nut with water and 0.027N NaOH showed 3 and 6 hands by polyacrylamide gel electrophoresis, respectively. 6. Amino acids of defatted hazel nut and protein isolate were chiefly composed of glutamic acid, arginine and aspartic acid.

• Molecules and Cells
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• v.39 no.11
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• pp.790-796
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• 2016

Dental pulp is a highly vascularized tissue requiring adequate blood supply for successful regeneration. In this study, we investigated the functional role of stem cells from human exfoliated deciduous teeth (SHEDs) as a perivascular source for in vivo formation of vessel-like structures. Primarily isolated SHEDs showed mesenchymal stem cell (MSC)-like characteristics including the expression of surface antigens and in vitro osteogenic and adipogenic differentiation potentials. Moreover, SHEDs were positive for NG2, ${\alpha}$-smooth muscle actin (SMA), platelet-derived growth factor receptor beta ($PDGFR{\beta}$), and CD146 as pericyte markers. To prove feasibility of SHEDs as perivascular source, SHEDs were transplanted into immunodeficient mouse using Matrigel with or without human umbilical vein endothelial cells (HUVECs). Transplantation of SHEDs alone or HUVECs alone resulted in no formation of vessel-like structures with enough red blood cells. However, when SHEDs and HUVECs were transplanted together, extensive vessel-like structures were formed. The presence of murine erythrocytes within lumens suggested the formation of anastomoses between newly formed vessel-like structures in Matrigel plug and the host circulatory system. To understand underlying mechanisms of in vivo angiogenesis, the expression of angiogenic cytokine and chemokine, their receptors, and MMPs was compared between SHEDs and HUVECs. SHEDs showed higher expression of1VEGF, SDF-$1{\alpha}$, and $PDGFR{\beta}$ than HUVECs. On the contrary, HUVECs showed higher expression of VEGF receptors, CXCR4, and PDGF-BB than SHEDs. This differential expression pattern suggested reciprocal interactions between SHEDs and HUVECs and their involvement during in vivo angiogenesis. In conclusion, SHEDs could be a feasible source of perivascular cells for in vivo angiogenesis.

• Applied Microscopy
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• v.30 no.4
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• pp.337-345
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• 2000

Introduction of the buffer layer and the nitridation of a sapphire substrate were one of the most general methods employed for the reduction of lattice defects in GaN thin films Brown on sapphire by MOCVD. In an effort to improve the initial nucleation and growth condition of the GaN, reactive ion beam (RIB) of nitrogen treatment of the sapphire surface has been attempted. The 10 nm thick, amorphous $AlO_xN_y$ layer was formed by RIB and was partially crystallized alter the main growth of GaN at high temperature, leaving isolated amorphous regions at the interface. The beneficial effect of amorphous layer at interface in relieving the thermal stress between substrate and GaN film was examined by measuring the lattice strain value of the GaN film grown with and without the RIB treatment. Higher order Laue zone pattern (HOLZ) of $[\bar{2}201]$ zone axis was compared with simulated patterns and lattice strain was estimated It was confirmed that the great reduction of thermal strain was achieved by RIB process and the amount of thermal stress was 6 times higher in the GaN film grown by conventional method without the RIB treatment.

• Applied Microscopy
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• v.19 no.1
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• pp.1-18
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• 1989

It has been debated whether postischemic reperfusion is necessarily beneficial to salvage the myocardium after ischemic insult or not. Therefore, this study was undertaken to compare the ultrastructural changes as well as the distribution of $Ca^{2+}$ in the ventricular myocardial cells after transient ischemia and after postischemic reperfusion, and to suspect to what extent the postischemic reperfusion is beneficial. After 10 minutes of ischemia, the heart developed wide I bands, glycogen depletion, intramyofibrillar edema, mitochondrial swelling, clumping and migration of chromatin, ghosts of lipid droplets, disintegration of cell junctions, sarcolemmal disruption, and loss of $Ca^{2+}$ binding capacity of the sarcolemma and the mitochondria. In spite of reperfusion, in a large number of cells, the ultrastructure was more severely damaged, however, $Ca^{2+}$ binding capacity of the sarcolemma and the mitochondria restored. These results suggest that postischemic reperfusion may help the myocardial cells to restore their function to control $Ca^{2+}$ to a certain extent, but that it could aggravate the ischemic insult.