C3植物中PEPCase及其有关酶活性的研究

本实验以C3植物小麦、大豆为材料研究了不同光合器官和生长发育过程中PEPCase及其有关的酶活性。主要结果如下: 1．C3植物中谱遍存在着一定活性的PEPCase，特别是在结实器官的各部位中有着较高活性和比例的PEPCase以及与PEPCase相邻作用的苹果酸酶和苹果酸脱氢酶，如小麦的内稃，大豆的荚壳，种皮中PEPCase活性高于其本身的RuBPCase活性，说明C3植物的结实器官中存在着活跃的CO2β一羧化作用。 2．大豆、小麦结实器官的14CO2暗固定量均比叶片高，因此在这些器官中存在着活跃的CO2暗固定作用，这对植物经济利用碳素提高光合同化效率和籽粒产量有着十分重要的意义，同时CO2暗固定的中间产物能参与其它代谢途径，因此这些器官中的PEPCase时作用是多方面的。 3．RuPEPCase、PEPCase在植物的生长发育过程中其活性发生明显的变化，二种羧化酶活性在生殖期最高，这对于结实器官的形成和发育是十分有意义的。 4．大豆荚果作为光合器官，具有光合同化CO2的生理生化基础—叶绿素和一足活性的PEPCase、RuBFCas e和结构基础—在一定区域细胞内存在着大量的叶绿体。小麦、大豆的结实器具有一定活性的RuBPCase和较高活性的PEPCase，能进行一定程度的光合碳同化，对作物产量的形成和贡献有着不可低估的作用。

Seasonal variations in the activity budget of Nomascus concolor jingdongensis at Mt. Wuliang, Central Yunnan, China: Effects of diet and temperature

We studied seasonal variation in the activity budget of a habituated group of Nomascus concolor jingdongensis at Mt. Wuliang, Central Yunnan, China from March 2005 to April 2006 via scan sampling at 5-min intervals. The study site is near the northern extreme of the distribution of hylobatids, at high altitude with extreme seasonality of temperature and rainfall. During the day, feeding manifested a bimodal pattern of high activity levels in mid-morning and mid-afternoon, whereas resting reached a peak at midday, with proportionally less time used for traveling. Annually, the group spent an average of 40.0% of the time resting, 35.1% feeding, 19.9% traveling, 2.6% singing, 1.2% playing, and 1.3% in other activities. The proportion of time allocated to activities showed significant monthly variations and was influenced by the diet and temperature. Gibbons increased traveling and playing time and decreased feeding time when they ate more fruit, and they decreased traveling, singing, and playing time and increased feeding time when they ate more leaves. Moreover, when the temperature was low, the gibbons decreased time traveling and increased time resting. In summary, black-crested gibbons employed high-effort activities when they ate more fruit and energy-conservation patterns when they ate more leaves and in low temperature. Behavioral data from the site are particularly useful in understanding gibbon behavioral adaptations to different sets of ecological conditions.