• Journal of Environmental Science International
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• v.2 no.1
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• pp.37-48
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• 1993

Effect of plant hormones on the leaf senescence of mung bean (Phseoln radiatus) was investigated by measuring the changes of reducing sugar contents and invertase isozyme activities in detached leaves treated with NAA, $GA_3$ or BA. During dark-induced senescence, reducing sugar contents in the detached leaves increased temporarily at 4 6, thereafter decreased rapidly and reached minimum values within 7-14 6. The pattern of soluble acid invertase activity in the senescing leaves kept in the dark was similar to that of reducing sugar accumulation, whereas the activities of alkaline and extracellular invertases were not significantly changed during leaf senescence. Therefore, these results suggest that soluble acid invertase, but not alkaline and extracellular invertases, induces the accumulation of reducing sugar during leaf senescence of Rung bean plants. Exogenous NAA application had little or no effect In the increase of soluble acid invertase activity during dark-induced senescence compared to the control. However, exogenous applications of $GA_3$ and BA led to the increase of soluble acid invertase activity in the senescing leaves. Particularly, BA application was very effective In enhancing the activity of soluble acid invertase as well as in delaying chlorophyll breakdown during dark-induced senescence. These results suggest, therefore, that BA regulates the activity of soluble acid invertase, which leads to the accumulation of reducing sugar, and the stability of photosynthetic apparatus to delay leaf senescence.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.2
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• pp.3-10
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• 1982

This experiment was conducted to study the effect of soil water potenial on the growth and internal changes of stressed plants. The experimental imposition of soil water potential ( $\Psi$soil) were -0.1 to -0.2, -0.2 to -0.5, -0.5 to -3.0, -3.0 to -10.0 bar respectively. During water stress all growth rates were depressed, and the most sensitive period to water stress was found to be 10 to 25 days after transplanting. The water potential of leaf was declined rapidly within 12 hours after with holding of water. Nitrate reductase activity was decreased progressively as water deficit was built up in tobacco leaves, but the activity of alpha- amylase and super contents were increased. There were differences in peroxidase isozyme patterns between tile control and water stressed plant. New isozymes started to appear as tobacco leaf water potential decreased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.211-215
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• 1994

Lipoxygenase is involved in the formation of certain undesirable flavors of soybean products. Three isozymes(L-1, L-2 and L-3) of lipoxygenase have been identified in soybean seeds, and the three types of mutants lacking L-1, L-2 and L-3, respectively, were detected in the 1980's. In this paper, lipoxygenase activity was measured to investigate the response of lipoxygenase in organs and tissues during soybean development. There was no tendency according to genotypes between lipoxygenase lacking mutants and normal soybeans in lipoxygenase activity of leaf at $V_3$ and $V_5$ stage. Likewise, pod wall lipoxygenase was no difference among genotypes tested at R$_{6}$ stage. Seed coat lipoxygenase activity was similar among the lipoxygenase lacking mutants, while normal soybean was lower as compared with that of the lipoxygenase lacking mutants. Embryo and cotyledon lipoxygenase activity in the lipoxygenase lacking mutants was much lower than that of normal soybean, also there was large difference among lipoxygenase lacking mutants. Thus, the lipoxygenase null mutant showed very weak value although the lacking L-3 mutant had a large effect on developing embryo lipoxygenase activity. It was suggested that soybean lipoxygenase isozymes expressed in embryo may be different from those expressed in the pod wall and leaf tissues.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.1-16
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• 1985

This experiment was conducted to study sex expression and subsequent changes in protein and peroxidase after three cultivars of cucumber plants were treated with ethephon and gibberellin. The three cultivars of cucumber used in this study included 'Sayeup' (monoecious type), 'Sinrokdadaki' (gynoecious type), and 'Seonghowon' (intermediate type). The ethephon at 250 ppm and gibberellin at 100 ppm were treated at the 2-leaf and 4-leaf stages, and subsequent sex expression and changes in protein contents, peroxidase activities and isoperoxidase banding patterns by disc polyacrylamide gel electrophoresis were studied. The results can be summarized as follows: 1. Ethephon treatment slightly increased number of pistillate flowers and significantly decreased number of staminate flowers in the three cultivars, while gibberellin treatment significantly increased number of staminate flowers in both gynoecious 'Sinrokdadaki' and intermediate 'Seonghowon' and did not increase number of staminate flowers in monecious 'Sayeup' 2. There were some differences among three cultivars in protein contents, protein banding and isoperoxidase banding patterns of seeds and germinating seeds. However, it was not obvious to differentiate monoecious from gynoecious cultlvars by these characters. 3. Protein contents in the leaves. and stem apex after ethephon and gibberellin treatment increased gradually at the 2-leaf stage, but decreased at the 4-leaf stage. Protein contents in stem apex at the 4-leaf stage without treatment were much higher in 'Sinrokdadaki' and 'Seonghowon' than in monoecious 'Sayeup'. Protein contents in the stern apex at the 4-leaf stage were increased in the ethephon-treated monoecious 'Sayeup' and decreased in 'Sinrokdadaki' and 'Seonghowon' compared with untreated plants. 4. Peroxidase activities in the leaves and stem apex gradually decreased at the 2- leaf stage, but increased at the 4-leaf stage. Peroxidase activities in stern apex at the 4-leaf stage were significantly increased by ethephon treatment. 5. The number of protein bands in the three cuitivars after treatment gradually decreased in leaves and stem apex at the 2-leaf stage, but increased in the 4-leaf stage. The protein banding pat terns of stern apex of the ethephon-treated monoecious 'Sayeup' at the 4-leaf stage were gradually shifted to the banding.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.175-181
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• 1997

Plants were regenerated from hypocotyl protoplast culture of cabbage (F$_1$hybrid Green Challenger) and were transplanted on fields. The ploidy level of regenerated and seed-grown plants was measured by flow cytometry. In total 125 regenerated plant, diploid (2n), tetraploid(4n), and mixoploid (2n+4n) were 72.8%, 25.6%, and 1.6%, respectively. Most of the regenerated plants had normal phenotype, whereas several plane showed abnormal phenotype such as heavy leaf incision, savoy, and wave. The regenerated plants with abnormal phenotype and different ploidy level were analysed by isozyme and RAPD, but no significant difference was found.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.81-92
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• 1996

This study was conducted to characterize mulberry varieties by the analysis of morphological characters as well as biochemical and molecular biological markers. As for the budding stage Geumsang, Chosang i and Yeongbyeonchuwoo were early, but Dangsang 6, Hwangchuwoo were late. The lowest varietiy in rate of death atop was Dangsang 8(0.0%). Suncheonppong was the highest leaf yields in spring and autumn rearing season. In biochemical isozyme analysis, peroxidase gave good zymogram patterns in isoelectric focusing electrophoresis. There were high variations in RAPD analysis among the mulberry trees. From the obtained peroxidase and RAPD variations, cluster phylogenetic analysis was carried out using NT-SYS PC program. There were no clear grouping patterns between native varieties and leading varieties. The highest similarity was observed between Suwonsang 1 and Suwonsang 2 at about 90% similarity level.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.335-341
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• 2008

In this study, hexaconazole 5% SC, an ergosterol biosynthesis inhibitor, was tested on groundnut with its recommended ($500\;mL\;ha^{-1}$) and higher ($2,000\;mL\;ha^{-1}$) concentrations under greenhouse conditions in India. Its influence on biochemical constituents of groundnut plants was assessed apart from its disease management potential against late leaf spot caused by Phaeoisariopsis personata (Berk and Curt). Likewise, leaf samples were collected from hexaconazole 5% SC-sprayed plants at different time intervals. Thereafter, their analyses showed considerable differences in the plant constituents, such as chlorophyll, soluble protein, and total phenol contents and the activity of nitrate reductase enzyme. The induction activity of defense-related enzyme, peroxidase, was also analyzed. However, no difference was observed in the isozymic pattern. Moreover, the ground kernels collected from treated plants also showed no difference in the estimated carbohydrate and other constituents.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.178-183
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• 1985

The present researches were carried out to investigate the peroxidase activity in association with the reactions of the 4 cultivars of rice plant, Nagdong, Jinheung, Nongbaek and Taebaek to Pyricularia oryzae race KJ-I0l and KJ-301. Although the peroxidase activity was increased during the growth of the rice seedlings, the significant difference in the activity was not found among 4 cultivars. After inoculation of the fungus, the peroxidase activity was enhanced in diseased leaves, being considerably higher in the compatible than in the incompatible cultivars. The isozyme bands of peroxidases observed in mycelium of rice blast fungus were not found in the diseased leaves on the gel electrophoresis. The peroxidase activity was not affected by the increased application of nitrogenous fertilizer.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.167-176
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• 1997

Characteristics of leaf morphology and vegetation were examined in 6 populations of rare endemic tree species, Koelreuteria paniculata Laxm. Additionally we studied genetic variation employing isozyme marker. Nested anova showed that there were statistically significant differences among populations as well as among individuals within populations in all 8 leaf morphological traits. In 7 of 8 traits, variance components among populations were larger than those among individuals within populations. Only a few tree species were found within each population and all the populations seemed to have been disturbed by man. Level of genetic diversity for this rare endemic species was very low, especially compared with those of geographically widespread tree species(A/L=1.1, P=9.5%, $H_o=0.021$, $H_e=0.035$) and degree of genetic differentiation was high($F_{ST}=0.114$). Factors contributing to the low level of genetic diversity and high level of genetic differentiation might include genetic drift, inbreeding and limited gene flow. Finally, implications for the conservation of genetic diversity of Koelreuteria paniculata were discussed.

• Journal of Life Science
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• v.13 no.1
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• pp.1-8
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• 2003

Antioxidant activity and biological properties in the MeOH extracts from different plant parts of Euonymus alatus (THNUB.) were measured by DPPH free radical scavenging ability and inhibition ability against xanthine/xanthine oxidase and proliferation in HL-60 cells. DPPH free radical scavenging activities in extracts of plant parts were high such as leaf, wing, root, seed and stem, respectively. The EtOAc fractions of plant parts were purified through LH-20 column chromatography and identified by GC/MS. LH-4 fraction and LH-5 fraction of leaf, stem and root showed stronger activities than other fractions in the inhibitor activity of DPPH and xanthine/ xanthine oxidase. $IC_{50}$ values of LH-4 fraction eluted from stem extracts showed such as 2.38 and 5.32 in DPPH and xanthine/ xanthine oxidase assay. Polyphenolic compounds were identified in purified LH-20 fractions showed highest $IC_{50}$ value in DPPH and xanthine/xanthine oxidase assay The activity of POD according to sampling time was high in root harvested in May and leaf harvested in September, respectively. The activity of SOD showed only in the extracts of stem in plant parts. SOD and POD in leaf were similar in the patterns of isozyme to those of stem. The purified extracts from Euonymus alatus (THNUB.) exerted inhibition ability of proliferation in HL-60 cells.