• Korean journal of applied entomology
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• v.37 no.2
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• pp.179-185
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• 1998

The effect of physiological factors of beet armyworm, Spodoptera exigua (Hubner), on esterase variation was analyzed by comparing electrophoretic esterase isozymes. Each esterase isozyme was also characterized by substrate and inhibitor specificities. A total of 28 esterase isozymes were separated on 10% nondenaturing polycarylamide gel electrophoresis (PAGE). These isozymes were denoted from El to E28 according to cathodal migration distances. There was a variation in esterase isozymes among developmental stages. Larvae and pupae had more isozymes than did adults. Eggs had only eight isozymes. The isozymes of El and E2 were specific only in the first instar larvae. Esterases also showed variation according to different tissues. More kinds of esterase isozymes were found in epidermis and gut tissues than in hemolymph and fat body. Some isozymes were specific in epidermis (from El to E6), gut (E10, El 1, E25, E26, and E27), and hemolymph (E18). Among 10 naphthyl esters, a-naphthyl propionate was the most reactive substrate to the esterase isozymes. The isozymes were classified into cholinesterases (El0 and E24), arylesterases (E4, E9, E17, E19, E21, and E23), and carboxylesterases (the others) on the basis of inhibition by the esterase inhibitors-eserine, dichlorovos, moncrotophos, and paraoxon.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.80-86
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• 1998

Changes in activity and classification of esterase isozymes during the tire cycle or Plodia inteipunctella (Hiibner) were investigated by the native polyacrylamide gel electrophoresis. The stage specificity in esterase activity and isozyme pattern was observed throughout the larvalpupal-adult transformation. The activity esterase was highest at the 3-day old adult stage, and the lowest level at the prepupal stage. A total of 12 esterase bands were identified throughout the development, and the bands showing high enzyme activity was observed in the middle part of gel. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates, eserine sulfate and sulfhydryl reagents) were classified into three class, namely, carboxylesterase (CE), arylesterase (ArE) and cholinesterase (ChE), and these classes contained 7, 3 and 2 isozymes, respectively.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.117-124
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• 2007

Esterase activity was observed after pesticides treatment in eggs of H. axyridis to select low toxicity pesticide. Egg esterases of H. axyridis were examined using an esterase substrate(${\alpha}$-naphthyl acetate). Three esterase isozymes were detected and the activities were inhibited by organophosphorus insecticide (Chlorpyrifos and Phenthoate), organochlorine insecticide(Methidation), triazole fungicide(Hexaconazole and Triflumizole), and pyrimidine fungicide(Nuarlmol). Fecundity and hatchability in adults and eggs of H. axyridis were examined on selected pesticides. Fecundity and hatchability were significantly reduced from H. axyridis adults and eggs treated with the pesticides and the fungicides showed strong inhibition of esterase isozymes activities. However, we also observed the pesticides and the fungicides showed low or non-inhibition of esterase isozymes activities affected on fecundity and hatchability in adults and eggs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.332-339
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• 1996

Electrophoretic method was utilized to classify 100 varieties of sweet potato germplasm maintained at the National Crop Experiment Station of Korea in 1993. The esterase isozyme patterns in the leaves were classified into 14 different types. Type Ⅸ included the most of the varieties (46) tested and Ⅶ, I, III, Ⅷ, II and V types of all included 47 varieties in order. The other 7 varieties had different band pattern with each other. Type I having many kind of band pattern included Shinyulmi, Beniastma and High starch which had the dry type of tuberous roots varieties. The esterase isozymes pattern in the tuberous roots were classified with 18 kinds of types. The C type included 22 varieties and B, K, A, E, I and N in order. The proteins pattern in the tuberous roots were classified with 7 kinds of types. I type included 36 varieties, and IV type included 27 varieties and II, III, Ⅶ and Ⅵ types in order.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.170-175
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• 1990

These studies were conducted to examine the mechanism of acaricidal resistance in the twospotted spider mite (Tetranychus urticae Koch). The resistant strains were obtained by succssive selection of five acaricides including carbonphenothion and ethion of organophosphorus compound, dicofol of organochlorine compound, cyhexatin of compound and biphenthrin of synthetic pyrethroid. Esterase isozymes were separated by polyacrlyamide gel susceptible strains. The differences of the esterase isozymes of the resistant strains were Est. 1, Est. 3 in the carbonphenothion-selected strain, Est. 3 in the ethion- and the cyhexatin-selected strains, Est. 1, Est. 3, Est. 7 in the dicofol-selected strain, Est. 7 in the biphenthrin-selected strain as compared to the susceptible strain. With the difference of electrophoretic bands and their activities, esterases were related to the resistant mechanism of tested acaricides.

• Journal of the Korean Society of Tobacco Science
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• v.21 no.1
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• pp.49-56
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• 1999

Classification of esterase isozymes of the apterous green peach aphids (Myzus persicae Sulzer) collected in tobacco fields were investigated by the native polyacrylamide gel electrophoresis (PAGE). A total of twelve esterase bands were identified in adult apterous aphid, and the difference of enzyme band activity in the clones was observed at the first and second bands group. Esterases of green peach aphids reacted with specific substrate were more stained $\alpha$-naphthyl acetate than $\alpha$-naphthyl propionate, and $\alpha$-naphthyl acetate more than $\beta$-naphthyl acetate. Twelve esterases on the basis of inhibition by the three types of inhibitors (organophosphates: 2.5$\times$10$^{-3}$ M paraoxon, 4$\times$10$^{-3}$ M DFP; eserine sulfate : 2$\times$10$^{-3}$ M eserin; sulfhydryl reagents: 2$\times$10$^{-3}$ M p-HMB) were classified into three class, namely, cholinesterase (ChE) I, II, carboxylesterase (CE) and arylesterase (ArE), and these classes contained 3, 4, 3 and 2 isozymes, respectively.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.11-22
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• 1991

This experiment was executed to investigate the possibility of the application of taxonomic method through the isoelectric focusing with polyacrylamide gel and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with seeds in the identification of turfgrasses. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to investigate the pattern of seed proteins which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The isoelectric focusing with polyacrylarnide gel was used to investigate the activity of the three isozymes of esterase, peroxidase and phosphoglucose isomerase which were extracted from 18 cultivars of cool season turfgrass and 4 cultivars of warm season turfgrass. The results were summarized as follows. 1. The difference of the patterns of seed proteins was observed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The identification of intra-genus was easily detected. 2. The three isozymes of esterase, peroxidase and phosphoglucose isomerase were investigated through isoelectric focusing with polyacrylamide gel. As a result, esterase was most effective among three isozymes in the identification of turfgrass cultivars 3. In the past cultivar identification was primarily based on visual morphological characters, but there was a lot of difficulty. If we should use electrophoresis, we will be able to identifvturfgrass cultivars more effectively.

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.44-45
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• 1986

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.179-185
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• 2007

Esterase isozymes were investigated from digestive juice of M. saltuarius adults after pesticide treatment. Twelve esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, and ${\alpha}$-naphthyl butyrate). Interestingly, the isozyme of Est1(${\alpha}$-naphthyl acetate) was strongly inhibited by the carbofuran and methomyl. The Est1 activity was completely inhibited by the chlorpyrifos and partially inhibited by methidation about 70 %. In addition, eserine suppressed esterase isozyme activities of Est1 about 70% and isozyme activities of Est2, Est3, and Est4 were weakly inhibited. ${\alpha}$-pinene did not suppressed esterase isozyme activities but activities of esterases were very weakly inhibited in camphor and bornyl acetate.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.171-178
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• 2007

Esterase isozymes were extracted from final instar larvae of M. saltuarius treated with selective diets and inhibitors. Twenty esterase isozymes were separated on 12% native-PAGE gel and stained with three different substrates(${\alpha}$-naphthyl acetate, ${\beta}$-naphthyl acetate, or ${\alpha}$-naphthyl butyrate). Interestingly, the isozymes of Est7(${\alpha}$-naphthyl acetate and ${\alpha}$-naphthyl butyrate) and Est6(${\beta}$-naphthyl acetate) were specifically activated in final instar larvae fed with the bark of Pinus koraiensis. However, we could not find any band from substrate ${\beta}$-naphthyl stearate. The esterase activities of Est3, Est6, and Est7 were inhibited by organophosphate and carbamate insecticides. In addition, The esterase activities of Est4, Est6, and Est7 were also inhibited by eserine. However, inhibition of esterase activities in methoprene, bornyl acetate, linal, cineol, and citral was not observed. However, It is necessary to reconfirm these results in vivo.