• Journal of Korean Society of Forest Science
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• v.81 no.1
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• pp.11-20
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• 1992

This study was conducted to compare chlorophyll contents, photosynthetic abilities, and ribulose-diphosphate (RuDP) carboxylase activities of Quercus acutissima seedlings grown with and without cotyledons under different light intensities and different nutrient levels. The results obtained in this study were as follows : 1. Chlorophyll contents were not significantly different among the light intensities except for 25% of full sunlight at the last harvest time. 2. RuDP carboxylase activity increased with increasing light intensity. 3. Photosynthetic abilities of seedlings grown under full and 75% of sunlight were significantly higher than that under 25% of full sunlight. 4. RuDP carboxylase activity was more related with chlorophyll a contents(r=0.792) than chlorophyll b contents(r=0.314). 5. RuDP carboxylase activities of the seedlings received at 1 or 2% addition rates of nutrients under 75% of full sunlight were higher than that at 0.5% addition rates.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.115-124
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• 1988

This study was carried out to realize the effect of gibberllic acid$(GA_3)$, 1-naphthaleneacetic acid(NAA) and indole-3-acetic acid(IAA) on the biosynthesis of vitamin C. The relation between carbohydrate metabolism and vitamin C production in soybean sprouts was also investigated. Growth, vitamin C content, protein, galactonolactone dehydrogenase(GLD), ribulose diphosphate carboxylase(RuDpCO) and RNA level in the plastid and cytoplasm were determined. The effects of protein and respiratory inhibitors on the growth and vitamin C production were also examined. The most favourable growth of soybean sprouts was observed at the level of NAA $10^{-8}M,\;IAA10^{-6}M\;and\;GA_3\;10^{-5}M$ in the single treatment, respectively, and also favourable at levels of $GA_3\;10^{-5}M+NAA\;10^{-9}M\;and\;GA_3\;10^{-5}M+IAA\;10^{-9}M$ in the case of mixed treatment. The excellent growth was observed at the level IAA $10^{-6}M$ among all the single and mixed treatments. When the soybean sprouts were treated with NAA $10^{-8}M,\;IAA\;10^{-6}M\;GA_3\;10^{-5}M,\;GA_3\;10^{-8}M+IAA\;10^{-6}M,\;and\;GA_3\;10^{-5}M+IAA\;10^{-9}M$, the maximum growth rate was observed at the level of IAA $10^{-6}M$ and the conten of vitamin C was 24.26mg% which was 1.6 times higher than that of the control. RuDpCO was inhibited by the chloramphenicol at the concentration that did not inhibit the growth but the activities of NADP-GDH, GLD and vitamin C content were not affected. These results showed that the biosynthesis of viamin C had nothing to do with the activity of chloroplastic RNA but with cytoplasm. The highest vitamin C content was found at the the level of IAA $10^{-6}M$, where the GLD activity increased up 1.8 times of the control. The concentration of IAA $10^{-6}M$ promoted the biosynthesis of RNa and protein both in chloroplast and cytoplasm, especially in the cytoplasm. Thus it suggeted that IAA affected vitamin C biosynthesis by regulating RNA level in the cytoplasm. 2,4-Dinitrophenol as an uncoupler of oxidative phosphorylation did not inhibit the vitamin C biosynthesis, however, all of the respiratory inhibitors severely inhibited the growth and vitamin C biosynthesis.