• Korean journal of applied entomology
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• v.51 no.4
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• pp.349-356
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• 2012

Eicosanoid mediates various cellular immune responses in insects. This study aimed to discover its novel action on the modulation of hemocyte populations in response to an immune challenge. Upon bacterial challenge, the last instar larvae of the beet armyworm, Spodoptera exigua, increased their total hemocyte density in 2 h, and then decreased it to a basal hemocyte density level. This rapid increase in total hemocyte density was explained by an increase of plasmatocyte and spherulocyte densities. When larvae were treated with dexamethasone (a specific phospholipase $A_2$ ($PLA_2$) inhibitor), they did not show any increase in hemocyte density in response to bacterial challenge. However, the addition of arachidonic acid (a catalytic product of $PLA_2$) to larvae treated with dexamethasone recovered the up-regulation of hemocyte density in response to bacterial infection. Among eicosanoid, cyclooxygenase (COX), but not lipoxygenase (LOX), products seemed to mediate the increase of hemocyte density in response to bacterial infection because naproxene (a COX inhibitor) inhibited the hemocyte density increase, though esculetin (a LOX inhibitor) did not. Prostaglandin $E_2$, a COX product, significantly increased the hemocyte density even without bacterial infection. These results suggest that eicosaniod mediates a rapid increase in total hemocyte density in response to immune challenge.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.452-458
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• 2012

Rare earth elements fertilizer and Ca were sprayed on eight-year-old 'Fuji'/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at $4^{\circ}C$ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in 'Fuji' apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of 'Fuji'/M.9 apple fruit.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.445-451
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• 2012

The thinning effects of lime sulfur either alone or combined with fish oil on two apple cultivars 'Fuji'/M.9 and 'Hongro'/M.9 were investigated during two consecutive seasons. Either 1% or 2% lime sulfur at full bloom decreased the amounts of both terminal and axillary fruits compared with unsprayed 'Fuji' control trees in the first year. However, 1% or 2% lime sulfur did not decrease terminal fruit set in the second year. Only, triple applications of 1% lime sulfur significantly reduced the number of terminal and axillary fruits in both years. Multiple application of 1% lime sulfur was the most effective in thinning of 'Hongro'. In the first year, double or triple applications of 1% lime sulfur was effective in thinning terminal or axillary fruit, but one time applications of 1% or 2% lime sulfur was not reduced axillary fruit in 'Hongro' apple trees. In the second season, all treatments reduced terminal or axillary fruit in 'Hongro' clusters, except single application of 1% lime sulfur. Fish oil did not always improve the thinning effects of lime sulfur in 'Fuji' or 'Hongro' apple trees. None of treatments caused significant russeting in the harvested fruits. Most of thinning treatments had little effect on 'Fuji' or 'Hongro' fruit quality in terms of fruit weight, firmness, soluble solids concentration or titratable acidity.

• Journal of Life Science
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• v.16 no.1
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• pp.108-113
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• 2006

To compensate the problems of chemical assay in detoxification of recalcitrant and a practical approach in selection of bioremediation bacteria, a simple and rapid toxicity evaluation system was constructed based on Lumbricus rubellus. Long term-culture and specific equipment are not necessary, and semi-quantitative analysis of toxicity at sub-lethal concentration is possible by measuring of dose-dependent increased yellowish secreted compounds. When the toxicity of endosulfan, its metabolites and structurally related chemicals were measured for 24 h, the results were coincided with previous reports. Toxicity was found in endosulfan, endosulfan sulfate, aldrin, and dieldrin, respectively. Rapid and economic selection of endosulfan-detoxifying bacteria was possible using our system. Klebsiella pneumoniae KE-1, K. oxytoca KE-8 and Pseudomonas sp. KS-2P, reported endosulfan degrading bacteria, ameliorated the endosulfan toxicity, whereas E. coli, B. subtilis and other bacteria failed to protect the toxicity of endosulfan in L. rubellus. Our results suggest that the constructed system is useful to selection of microorganism as well as toxicity evaluation against toxic recalcitrants.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.391-400
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• 2005

This study was undertaken to survey the pesticides used under the greenhouse cultivation of 9 vegetable crops including cucumber, tomato, strawberry, eggplant, hot pepper, paprika, lettuce, perilla leaves and green onion in the Southern area during the period of 2003-2004. The total number of farmers investigated was 202 which consisted of 124 conventional growers and 78 environment-friendly growers. The farmers were requested to record with respect to the crop's name, cultivation acreage, growing practices (conventional/environment-friendly), use purpose, pesticide kinds, usage quantity and application time of pesticides. The average usage quantity of pesticides for the 9 crops was 3.30 kg ai/ha in conventional growing and 0.47 kg ai/ha in environment-friendly growing. The average application time of pesticides was 11 times in conventional and 2 times in environment-friendly growing, with more than 90% cases as a foliar application. The number of active ingredients of pesticides was 34 in conventional and 10 in environment-friendly growing on the average per crop. The purpose of pesticide application was as a fungicide in 56% cases and as an insecticide in 43% cases.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.164-170
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• 2007

The concept of innate immunity in insects which refers to the first line of host defense constitutes the humoral and cellular components which are involved in recognition and actively participate in the elimination of the intruding foreign micro- or macro-organisms. Several recent studies suggest that juvenile hormone (JH) modulates the cellular immune reactions in response to pathogen. In this study, pyriproxyfen (a JH agonist as an insect growth regulator) was tested in its any inhibitory effect on the immune reactions of the beet armyworm, Spodoptera exigua. To this end, five different hemocyte morphotypes of final instar S. exigua were identified by phase contrast microscopy. Plasmatocytes and granular cells, which constitute about 90% of the total hemocyte count, were prominently distinguished based on their basophilic/acidophilic nature using Giemsa stain. The role of pyriproxyfen on the functional ability of hemocytes was analyzed using FITC-labeled Providencia vermicola for the phagocytic potential of the hemocytes. Both granular cells and plasmatocytes exhibited phagocytosis behavior. Pyriproxyfen significantly inhibited the phagocytosis of both cell types, proposing its novel action as an immunosuppressant.

• Journal of Life Science
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• v.18 no.4
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• pp.454-460
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• 2008

This study was carried out to demonstrate morphological, cytological and molecular evidence for intersubgeneric $F_1$ hybrid between Glycine tomentella and G. max cv. ‘Baemkong’. Morphological features of $F_1$ plant for pistil and stamen, flower color and growth habit showed intermediate type between G. tomentella and G. max cv. ‘Baemkong’. Chromosome number of $F_1$ plant was 2n=39, which explained the evidence of $F_1$ hybrid between G. tomentella (2n=38) and G. max cv. ‘Baemkong’ (2n=40). Polyacrylamide isoelectric focusing pattern for esterase and peroxidase also showed that the $F_1$ plant was true $F_1$ hybrid between G. tomentella and G. max cv. ‘Baemkong’. From RAPD analysis, we identified that 62 primers showing bands in $F_1$ hybrid had both bands from G. tomentella and G. max cv. ‘Baemkong’, which suggested that this was true $F_1$ hybrid. Based on our results from morphological, cytological and molecular analyses, we suggest that the $F_1$ plant was true intersubgeneric hybrid between G. tomentella and G. max cv. ‘Baemkong’. Our results still remain us further study to recover fertility of $F_1$ hybrids. The occurrence of maternal and/or paternal inheritance in $F_1$ hybrid from intersubgeneric cross between G. tomentella and G. max cv. ‘Baemkong’ need to be explained.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.555-566
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• 2018

Two rhizobacteria Bacillus aryabhattai H26-2 and B. siamensis H30-3 were evaluated whether they are involved in stress tolerance against drought and high temperature as well as fungal infections in Chinese cabbage plants. Chinese cabbage seedlings cv. Ryeokgwang (spring cultivar) has shown better growth compared to cv. Buram-3-ho (autumn cultivar) under high temperature conditions in a greenhouse, whilst there was no difference in drought stress tolerance of the two cultivars. In vitro growth of B. aryabhattai H26-2 and B. siamensis H30-3 were differentially regulated under PEG 6000-induced drought stress at different growing temperatures (30, 40 and $50^{\circ}C$). Pretreatment with B. aryabhattai H26-2 and B. siamensis H30-3 enhanced the tolerance of Chinese cabbage seedlings to high temperature, but not to drought stress. It turns out that only B. siamensis H30-3 showed in vitro antifungal activities and in planta crop protection against two fungal pathogens Alternaria brassicicola and Colletotrichum higginsianum causing black spots and anthracnose on Chinese cabbage plants cv. Ryeokgwang, respectively. B. siamensis H30-3 brings several genes involved in production of cyclic lipopeptides in its genome and secreted hydrolytic enzymes like chitinase, protease and cellulase. B. siamensis H30-3 was found to produce siderophore, a high affinity iron-chelating compound. Expressions of BrChi1 and BrGST1 genes were up-regulated in Chinese cabbage leaves by B. siamensis H30-3. These findings suggest that integration of B. aryabhattai H26-2 and B. siamensis H30-3 in Chinese cabbage production system may increase productivity through improved plant growth under high temperature and crop protection against fungal pathogens.

• Journal of Life Science
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• v.29 no.2
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• pp.164-172
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• 2019

In Korea, shiitake mushroom, Lentinula edodes, is cultivated on artificial medium containing oak sawdust and wheat bran. The annual production of spent mushroom substrate (SMS) of shiitake, a byproduct of the mushroom industry, is estimated to reach over 50,000 tons per year. This study aimed to improve the use of SMS as a novel bioresource. Hot water extracts of SMS after the first and third harvest were prepared and their bioactivities evaluated. Hot water extracts of uninoculated medium and shiitake were used as controls. Extracts of SMS showed higher radical scavenging of DPPH anions, ABTS cations, nitrites, and a higher reducing power than those of shiitake or medium extracts. After the first and third harvests at 0.5 mg/disc, SMS extracts showed no antibacterial or antifungal activities against the pathogenic and food-spoilage bacteria and fungi. However, they showed good inhibitory activities against ${\alpha}$-glucosidase at 0.5 mg/ml. In addition, SMS extracts had strong anti-coagulation activities via their inhibition of thrombin, prothrombin, and blood coagulation factors without platelet aggregation activity. Our results suggested SMS should no longer be perceived as a useless byproduct but should be understood as a novel bioresource, the extracts of which could be developed as antioxidant, antidiabetic, and antithrombosis agents.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.4
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• pp.15-25
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• 2022

In this study, the efficiency of treatment of moisture and organic matter in food waste was analyzed according to the air blast volume and preheating using the bio-drying method. Te mount of air blast volume and preheating were determined by the evaluation of temperature and CO2 during food waste treatment using the bio-drying method. As a results, the increase in the air blast volume increased the moisture removal efficiency and removal rate, but, lowered the temperature inside the bio-drying by the decease in microbial activity. In order to maintain the activity of microorganisms, it was estimated that it was necessary to inject an appropriate air blast rate according th the properties of the food waste. In this study, the injection of air blast volume at 15L/min was optimal. It was evaluated that the organic matter and water removal rates according to the presence or absence of air preheating, the organic matter removal rate and water removal rate increased by 3-5% when air preheating was not performed. Also, there was no internal aggregation caused by the generation of condensate inside the bio-drying. Therefore, for effective bio-drying of food waste, it is necessary to maintain an appropriate air blast volume to maintain microbial activity, and it is considered that injection through preheating of air is required.