• The Korean Journal of Mycology
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• v.19 no.3
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• pp.231-237
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• 1991

This study was conducted in order to find out biological control of sesame wilt and blight caused by Fusarium of oxysporum f. sp. vasinfectum and Phytophthora nicotianae var. parasitica by using Streptomyces spp. Two sesame pathogens, Fusarium oxysporum f. sp. vasinfectum and Phytophthora nicotianae var. parasitica were purely isolated from diseased sesame plants of the field. Streptomyces species were isolated from 72 soil samples collected from red pepper and sesame uplands in Chungbuk and selected as antagonists according to the results of dual culture. The selected Streptomyces isolates such as St-11 and St-20 were confirmed their antagonistic effect through mycelial inhibition zone and inhibitory effects on the mycelial growth of the pathogens by culture filterate of the antagonists. Inhibitory effects on the conidial germination of Fusarium oxysporum vasinfectum and Phytophthora nicotianae parasitica by the antagonists were also tested in addition to mycelial Iysis. The antagonists St-11 and St-20 showed inhibitory effect on growth of sesame seedlings after seeds soaked in the suspension. Effect of soil inoculation with antagonist St-11 showed 40 to 78 percent of control effect for two diseases in comparison with control under greenhouse.

• Toxicological Research
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• v.4 no.1
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• pp.37-45
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• 1988

Primary cultures of adult rat hepatocytes were used to study in vitro cytotoxic effects of T-2 toxin on liver cells. When T-2 toxin was added to the culture, a significant depression of the hormonal induction of ${\alpha}$-aminoisobutyric acid (AIB) uptake and tyrosine aminotransferase (TAT) activity was observed. However, T-2 toxin did not affect the uptake of ouabain into hepatocytes. Protein synthesis was inhibited by T-2 toxin, but RNA synthesis was not severely affected. The inhibitory effects of T-2 toxin on protein synthesis was diminished rapidly with culture time and the hepatocytes culture maintained control level of protein synthesis within 24 hrs.

• International Journal of Industrial Entomology and Biomaterials
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• v.45 no.1
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• pp.17-21
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• 2022

The present study aimed to determine whether a hemolymph prepared from Antheraea yamamai larvae had the same biological activities using a Bombyx mori hemolymph prior to exposure to lipopolysaccharide (LPS) in order to induce an inflammatory response. The effects of the hemolymph were determined using a reverse transcription-quantitative polymerase chain reaction to assess the expression of pro-inflammatory molecules. The A. yamamai hemolymph exerted anti-inflammatory effects on LPS-activated human monocytic leukemia cells via Toll-like receptor (TLR) 4-mediated suppression, similar to the B. mori hemocyte extract. Treatment with the A. yamamai hemolymph significantly suppressed LPS-induced upregulated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expression at all tested concentrations compared with the control, similar to the B. mori immune-challenged hemolymph. Finally, the A. yamamai hemolymph, like the B. mori immune-challenged hemolymph, suppressed all of these concentrations in a dose-independent manner. These results demonstrate that the hemolymph of A. yamamai exhibited important biologically active substances. Further in-depth functional studies are required to fully understand the mechanisms underlying the biological activities of wild-type silkworm hemolymphs.

• Journal of Life Science
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• v.11 no.1
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• pp.22-26
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• 2001

In estrogen-dependent MCF-7 human breast cancer cells, $E_2$ at 10 nM stimulated cell proliferation to over 200% compared to the untreated control. EGF and TGF${\alpha}$, which are known as the autocrine/paracrine growth factors induced by $E_2$, also directly stimulated the cell growth in almost as the same extent as $E_2$. DFMO which is the specific inhibitor of ODC could inhibit cell growth even at as low as 0.5 mM. In the treatment with 1 mM DFMO for 4 days, the cell growth was inhibited to 38% of the control. HO-TAM at 1 ${\mu}$M could inhibit the proliferation of MCF-7 cells to 19% of the control. Those inhibitory effects were also found in the cells stimulated with $E_2$, EGF, and TGF${\alpha}$. The inhibitory effects were found even in 2 days of treatment. However, $E_2$, EGF, and TGF${\alpha}$ did not give any effect in the protein synthesis. Neither DFMO or HO-TAM gave any effect on the total protein synthesis. But the pattern of protein secretion was noticeably influenced by the growth stimulants or inhibitors. Proteins of 160, 52, 42, 36, and 32 kDa belonged to the major secretory proteins. Especially, 42 and 36 kDa proteins were most significantly influenced by the treatment of $E_2$, EGF, or TGF$\alpha$. DFMO and HO-TAM inhibited the secretion of these major proteins.

• The Korean Journal of Ecology
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• v.23 no.6
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• pp.423-429
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• 2000

To understand the effects of elevated $CO_2$ concentration and temperature on seedling emergence of seven herbaceous species, the seedling emergence was monitored between November 1997 and May 1998 using a temperature gradient chamber and a $CO_2$-temperature gradient chamber. Experiment was conducted under current ambient condition (Control plot), 2$^{\circ}C$-warmed condition with ambient $CO_2$ (T2 Plot), 4$^{\circ}C$-warmed condition with ambient $CO_2$ (T4 plot). and 4$^{\circ}C$-warmed condition with 1.8 fold of ambient $CO_2$ (CT4 plot). Species tested in this study were Digitaria adscendens, Echinochloa crus-galli, Panicum bisulcatum, Setaria viridis. Oenothera biennis, Andropogon virginicus, and Imperata cylindrica. Each species often dominates in the herbaceous stage of secondary succession in Japan. The mean seedling emergence times for all species were significantly increased to 23.6 and 32.2 d in the T2 and T4 plot compared to the Control plot, respectively. The most sensitive and insensitive species in seedling emergence time in T2 plot were O. biennis and D. adscendens, respectivel.y, and those in the T4 and CT4 plot were I. cylindrica and D. adscendens, E. crus-galli and A. virginicus, respectively. All experimental species showed no significant difference in the seedling emergence rate between treatments except for O. biennis and I. cylindrica. O. biennis showed a great decrease in the seedling emergence rate from 83.3% in the Control plot to 38.0%, 14.7%, and 29.3% in the T2, T4, and CT4 plot, respectively. Elevated $CO_2$ had very little effect on the seedling emergence. From these observations, it is expected that increased temperature would greatly advance the vegetative recovery time after disturbance through the advancement of seedling emergence time.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.388-393
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• 2013

This study was conducted to select environmental friendly organic materials for controlling the ginseng alternaria blight and to evaluate their effects from 2011 to 2012. Alternaria blight is caused by Alternaria panax and is the most common ginseng disease in Korea. Environmental friendly organic materials were used to reduce amount of chemical fungicides and the number of spray for control of Ginseng Alternaria leaf blight. In 4 years of ginseng, control value of Alternaria leaf blight by single application of Defenoconazole WP was 82.3% and those of single application was 62.0~75.9%. Consequently, mixed or alternated application of eco-material products could be recommended as a control method to reduce the amount of fungicides.

• The Korean Journal of Mycology
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• v.44 no.1
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• pp.36-47
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• 2016

This study was conducted to evaluate five different strains of rhizobacterial isolates viz. PA1, PA2, PA4, PA5 and PA12 for biological control against Colletotrichum acutatum, C. coccodes, C. gloeosporioides, C. dematium, Botrytis cinerea, Rhizoctonia solani, Sclerotinia minor and Fusarium sp. In vitro inhibition assay was performed on three different growth mediums, potato dextrose agar (PDA), tryptic soy agar (TSA), and PDA-TSA (1:1 v/v) for the selection of potential antagonistic isolates. According to the result, isolate PA2 showed the highest inhibitory effect with 65.5% against C. coccodes on PDA and with 96.5% against S. minor on TSA. However, the same isolate showed the highest inhibition with 58.5% against C. acutatum on PDA-TSA. In addition, an in vivo experiment was performed to evaluate these bacterial isolates for biological control against fungal pathogens. Plants treated with bacteria were analyzed with phytopathogens and plants inoculated with phytopathogens were treated with isolates to determine the biological control effect against fungi. According to the result, all five isolates tested showed inhibitory effects against phytopathogens at various levels. Mode of action of these rhizobacterial isolates was evaluated with siderophore production, protease assay, chitinase assay and phosphate solubilizing assay. Bacterial isolates were identified by 16S rDNA sequencing, which showed that isolates PA1 and PA2 belong to Bacillus subtilis, whereas, PA4, PA5, and PA12 were identified as Bacilus altitudinis, Paenibacillus polymyxa and Bacillus amyloliquefaciens, respectively. Results of the current study suggest that rhizobacterial isolates can be used for the plant growth promoting rhizobacteria (PGPR) effect as well as for biological control of various phytopathogens.

• BMB Reports
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• v.40 no.1
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• pp.82-87
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• 2007

Our heterologous expression system of the human ferritin H-chain gene (hfH) allowed us to characterize the cellular effects of ferritin in yeasts. The recombinant Saccharomyces cerevisiae (YGH2) evidenced impaired growth as compared to the control, which was correlated with ferritin expression and with the formation of core minerals. Growth was recovered via the administration of iron supplements. The modification of cellular iron metabolism, which involved the increased expression of high-affinity iron transport genes (FET3 and FTR1), was detected via Northern blot analysis. The findings may provide some evidence of cytosolic iron deficiency, as the genes were expressed transcriptionally under iron-deficient conditions. According to our results examining reactive oxygen species (ROS) generation via the fluorescence method, the ROS levels in YGH2 were decreased compared to the control. It suggests that the expression of active H-ferritins reduced the content of free iron in yeast. Therefore, present results may provide new insights into the regulatory network and pathways inherent to iron depletion conditions.

• Research in Plant Disease
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• v.9 no.3
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• pp.174-178
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• 2003

Pseudomonas sp. antagonistic to Colletotrichum truncatum and C. gloesporioies was selected as a biological control agent for soybean anthracnose. Pseudomonas sp. inhibited the mycelial growth of pathogens effectively as the funhicides such as benomyl and fluazinam in vitro tests without any adverse effects on soybean. Seed treatment with Pseudomonas sp. increased emergence rate of soybean seeds significantly after inoculaton with C. truncatum. When the suspension of Pseudomonas sp. was sprayed on soybean plants, the control efficacy was not different from that of fungicides, benomyl and fluazinam two weeks after treatment, however the efficacy did not last long enough after three weeks.

• Journal of Life Science
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• v.6 no.4
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• pp.293-298
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• 1996

Thirteen subspecies of Bacillus thuringiensis including B. t. israelensis, B. t. morrisoni PG-14 and B.t. darmstadoemsos known to be toxic to dipteran insects were treated on the mushroom (Flammulina velutipes) compost to estimate the biological control effect of a sciarid fly, Lycoriella sp. According to the results, it was found that there were no significant effects of the tested strains of B, thuringiensis on the control of Lycoriella sp. For further confirmation, larval gut juice of Lycoriella sp. and trypsin were respectively treated into the parasporal crystal proteins of three subspecies of B. t. israelensis, B. t. morrisoni PG-14, and B. t. darmstadiensis. The proteins were separated by SDS-PAGE. According to the results, the major parasporal crystal proteins were respectively produced by B. t. morrisoni as the amount of 52 kd, B. y. israelensis as 37kd and B. t. darmstadiensis as 39kd, but the activity of these proteins could not be unfortunately confirmed in this study.