• Mycobiology
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• 제41권3호
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• pp.145-148
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• 2013

Vegetative growth signaling of the opportunistic human pathogenic fungus Aspergillus fumigatus is mediated by GpaA ($G{\alpha}$). FlbA is a regulator of G protein signaling, which attenuates GpaA-mediated growth signaling in this fungus. The flbA deletion (${\Delta}flbA$) and the constitutively active GpaA ($GpaA^{Q204L}$) mutants exhibit enhanced proliferation, precocious autolysis, and reduced asexual sporulation. In this study, we demonstrate that both mutants also show enhanced tolerance against $H_2O_2$ and their radial growth was approximately 1.6 fold higher than that of wild type (WT) in medium with 10 mM $H_2O_2$. We performed quantitative PCR (qRT-PCR) for examination of mRNA levels of three catalase encoding genes (catA, cat1, and cat2) in WT and the two mutants. According to the results, while levels of spore-specific catA mRNA were comparable among the three strains, cat1 and cat2 mRNA levels were significantly higher in the two mutants than in WT. In particular, the ${\Delta}flbA$ mutant showed significantly enhanced and prolonged expression of cat1 and precocious expression of cat2. In accordance with this result, activity of the Cat1 protein in the ${\Delta}flbA$ mutant was higher than that of $gpaA^{Q204L}$ and WT strains. For activity of the Cat2 protein, both mutants began to show enhanced activity at 48 and 72 hr of growth compared to WT. These results lead to the conclusion that GpaA activates expression and activity of cat1 and cat2, whereas FlbA plays an antagonistic role in control of catalases, leading to balanced responses to neutralizing the toxicity of reactive oxygen species.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.15-15
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• 2019

The walnut (Juglans regia L.), a member of the Juglandaceae, is native to the mountain ranges of central Asia. This species of walnut is valued commercially for its nuts and in some areas for its timber. The seeds of walnut are recalcitrant and it has strong integument dormancy and their germination is irregular, making its natural propagation difficult. Low percentage of seed germination and long propagation cycle are the main problems of propagation. This study was conducted medium composition on in vitro plantlet regeneration from axillary buds of walnut. It has proved to be the most generally applicable and reliable method of in vitro propagation. Micropropagation culture that axillary buds are excised aseptically enables faster multiplication of plants. The axillary buds of walnut new cultivar "Sinlyeong" were cultured on two basal media which contained the different plant growth regulators depending on the respective shooting and rooting stage. After 12 weeks, the shoot generation rate was 85.3%, the shoot number and its length were 1.9/explant and 2.7 cm in the most favorable medium composition. The percentage of rooting was 25.4%. From these results, it was found the optimum basal medium and plant growth regulator for in vitro plant regeneration from axillary buds of walnut new cultivar "Sinlyeong". However, we have continued to search the other medium additives to enhance the rate of walnut root.

• 한국자원식물학회지
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• 제2권1호
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• pp.235-241
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• 1989

The study was conducted to determine the Ms orthogonaL modia and the concentration of plant growth regulator for seed matura-tion and growth of rhizome from Cymbidium goeringii Germination waswell in dark condition, but the growth of rhizome was better un-der dark than under light condition in MS orthoTonal . Sucrose con-centration( 3 %) gave better results than higher ones(6%), andthe use of NAA(0.1 PPm) effect significant difference of seed ge-rmination .But the growth of rhizome was best in medium Containingsucrose concentration(3%) Ippm NAA and 1 PPm BA.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1988년도 정기총회 및 학술연구발표회
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• pp.42-43
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• 1988

• 한국작물학회:학술대회논문집
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• 한국작물학회 1998년도 춘계 학술대회지
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• pp.125-126
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• 1998

• Journal of Plant Biotechnology
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• 제2권1호
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• pp.51-54
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• 2000

Leaf explants of the cucumber (Cucumis sativus L.) were cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of $\alpha$-naphthalene acetic acid (NAA) and 6-benzylaminopurine (BAP). Direct shoot orgnogenesis as well as callus formation with somatic embryos and multiple shoots was observed from leaf explants of cvs. Shinhukjinju and Chungjang. The highest frequency of shoot formation 80% was observed on MS medium supplemented with NAA/BAP (5.0 ${\mu}{\textrm}{m}$/2.5 ${\mu}{\textrm}{m}$), with explants forming 3-7 shoots. Shoots formation occured within 3 to 4 weeks. Only one subculture of calli was required for plant regeneration on normal growth regulator-free medium. Plantlets transferred to soil developed into plants of normal appearance, which flowered and set fruits.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권1호
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• pp.61-67
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• 1997

The effects of Insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the copepod larvae of Tigriopus japonicus Mori. The larvae were cultured at control, 1, 5, 10, 20, 50, and 100 ppb Dimilin solutions and three replicate experiment were carried out to give correct analysis. Lethal effects of Dimilin on larvae of T. japonicus occurred above 1 ppb Dimilin solution after 8 days. $LC_{50}$ of larvae was 50 ppb Dimilin on the 4th day. Lethal effects of Dimilin on adults or T. japonicus occurred above 20 ppb Dimilin solution after 13 days. $LC_{50}$ of adults was 50 ppb Dimilin on the 12 days. Egg viability has little relation to Dimilin solution concentrations.

• 한국환경과학회지
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• 제1권1호
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• pp.61-67
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• 1992

The effects of insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the copepod larvae of Tigriopus japoniu Mori. The larvae were cultured at control, 1, 5, 10, 활, 50, and 100 pub Dimilin solutions and three replicate experiment were carried out to give correct analysis. Lethal effects of Dimilin on larvae of T japoniu occurred above 1 ppb Dimilin solution after 8 days. LC50 of larvae was 50 ppb Dimilin on the 4th day. Lethal effects of Dimilin on adults of T. japoniu occurred above 1 ppb Dimilin solution after 13 days. LC50 of adults was 50 ppb Dimilin on the 12 days. Egg viability has little relation to Dimilin solution concentrations.

• Molecules and Cells
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• 제37권6호
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• pp.480-486
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• 2014

Growth restriction by antibiotics is a common feature that pathogenic bacteria must overcome for survival. The struggle of bacteria to escape from growth restriction eventually results in development of antibiotic-resistance through the expression of a set of genes. Here we found that some physiologically important transcriptional regulators of Pseudomonas aeruginosa including QscR, a quorum sensing (QS) receptor, SoxR, a superoxide sensor-regulator, and AntR, a regulator of anthranilate-related secondary metabolism, are activated by various growth-restricted conditions. We generated the growth-restricted conditions by various methods, such as overexpression of PA2537 and treatment with antibiotics or disinfectants. The overexpression of PA2537, encoding an acyltransferase homologue, tightly restricted the growth of P. aeruginosa and significantly activated QscR during the growth restriction. Similarly, treatments with gentamycin, tetracycline, and ethanol also activated QscR near their minimal inhibitory concentrations (MICs). Some non-QS regulators, such as AntR and SoxR, were also activated near the MICs in the same conditions. However, LasR and PqsR, other QS receptors of P. aeruginosa, were not activated, suggesting that only a specific set of transcriptional regulators is activated by growth restriction. Since paraquat, a superoxide generator, significantly activated QscR and AntR, we suggest that the oxidative stress generated by growth restriction may be partly involved in this phenomenon.

• 한국응용곤충학회:학술대회논문집
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• 한국응용곤충학회 2001년도 추계 합동 심포지엄 및 학술발표대회
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• pp.62-62
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• 2001