• Journal of Ginseng Research
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• v.14 no.2
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• pp.122-125
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• 1990

Ethylene was released from leaf and fruit but root of Panax ginseng. Root callus showed higher ethylene release (ER) than fruit ER increased with leaf senesence. Fruit during ripening showed decreasing ER in the order of green stage, early stage of reddening and fully ripened stage. between leaves from the plant with fruits in different stages of ripening showed similar trend of fruit in ER but it was about 10 times higher in leaves than in fruits. Leaves of P. quinquefolius showed about 200 times higher ER than that of P ginseng on 22 July Fruits from the plant treated with ethephon showed higher ER after 109 days. Forty-five day-old seedlings grown with various growth regulators showed a significant decrease of stem length and significant increase of ER only in Uniconazole (0.1 ppm) and H-9 (0.0, 5 ppm) solution.

• Journal of Plant Biology
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• v.27 no.4
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• pp.241-251
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• 1984

The present study investigated the effects of triacontanol (TRIA) on plant growth and peroxisomal enzyme activities in radish seedlings. The optimum concentration of TRIA with respect to radish seedling bioassay was decided to 1.0mg $1^{-1}$. In comparison to untreated controls (including Tween 20 treatment), 1.0mg $1^{-1}$ TRIA treatment caused an increase in seed germination rate and root growth, but no stimulation in hypocotyl growth. Chlorophyll accumulation in cotyledon during carly development stage increased rapidly, and degradation of chlorophyll in later stage due to the cotyledon senesence was noticeably retarded. Increase of soluble protein content in cotyledon at early period of development was observed. Isocitrate lyase and catalase activity was not significantly different in both the treated and the untreated plants. But, glycolate oxidase activity was inhibited by TRIA down to 20% against controls. Also, the increase of the activity of peroxidase, a leaf-senescence marker enzyme, was continuously retarded over control for 8 days of development. Based on above results, TRIA was found to be active in both the growth and the peroxisomal enzyme activities of radish seedlings.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.3
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• pp.185-191
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• 1973

Effects of nitrogen sources on chlorophyll, activity of some oxidases in soybean leaves were investigated in relation to phosphorus sensitivity. Ammonium and urea culture accelerated leaf senescence more in phosphorus sensitive cultivars. The leaf senescence patterns affected by nitrogen sources were clearly indicated by intact leaf absorbance. Absorption maximum (670nm in methanol extraction or 685nm in intact leaf), was not changed by nitrogen source in the same method. According to leaf senesence pattern general physiological sensitivity pattern was discussed. IAA-oxidase activity was higher in the phosphorus tolerant cultivars and nitrate treatment than in the sensitive cultivars and ammonium treatment. Glycolate oxidase activity was higher in the sensitive cultivars and nitrate treatment. Polyphenol oxidase activity was higher in the tolerant cultivars and urea treatment. It is concluded that the excess ammonium, to which excess phosphorus is highly similar in physiological effect, disturbs the photosynthetic system by inhibition of ATP generation (photo-and oxidative phosphorylation).