Tea plants growing under natural condition meet various stresses. The tea plants often subjected to adverse condition like low temperature and high light intensity during overwintering. Because tea plant is adapted well to low light intensity, higher light intensity might induce negative effects on tea growth at open field (exposed habitat). We investigated tea plant planted with the seeds of wild tea trees growing at Unsu-ri, Hwagaemyun, Hadong-gun on Nov. in 2008. The experimental field for juvenile tea plants was located in the hill neighboring GSNU at Jinju, Korea. We divided the field into open, semi-shaded, and shaded condition. Light intensity (PAR) at open condition was two times and twenty times higher than at semi-shaded and shaded condition, respectively. Growth of tea plants was highly dependent on light condition, the plants at open field was extremely poor as compared to plants grown at shaded field. Height of plants at open, semi-shaded, and shaded field were 14, 17.3, and 17.8 cm, respectively. Leaf size was also greater in plants grown at shaded field. Photosynthesis-related chlorophyll fluorescence (quantum yield) was also higher in shaded plants. Fv/Fm value of plants grown at open fields was lower by 50% as compared to that of the plants grown at shaded field. Chlorophyll content measured by SPAD meter also indicated higher value in open field plant than shaded plants. Our results suggested the photoinhibition during overwintering period strongly affects the growth juvenile tea plants because there was no significant difference in soil moisture content between open and shaded condition.

Soybean sprouts produced at physiological optimal temperature around 20℃ are placed or displayed for several days in market shelf of relatively cool temperature (ca. 13℃). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, and etc. In order to know the changes, soybean sprouts packed in plastic film bag were stored at different temperature of 3℃and 13℃. Morphological characters, physicochemical changes and enzymes activity related to soybean quality (color) were examined. Although the number of fine roots and hypocotyl length were greater in sybean sprouts stored at 13℃, there was no significant difference in diameter, fresh weight and dry weight of hypocotyl between storage temperatures. Browning of hypocotyl known as typical deterioration in sprout quality was highly dependent on the activity of polyphenol oxidase (PPO) in hypocotyl. Considering the low level of soluble protein in hypocotyl, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprout. PPO activity of sprouts stored at 13℃ was 2 times higher than that of sprouts stored at 3℃ after 4 days. The PPO activity was observed no longer than 6 day in sprouts stored at 13℃. Crude protein content was increased to 30.9～35.4% on a dry weight basis as storage period was extended. The changes in crude protein was more higher in sprouts stored at higher temperature (13℃). Total free amino acid content was increased in both temperatures. However, the changing rate was greater in sprouts stored at 13℃.