中文摘要：

以祁连圆柏和圆柏为材料，测定分析了圆柏属两种常绿木本植物叶片代谢产物在冷冻适应过程中的季节变化，结果表明：在生长季节（夏季），祁连圆柏和圆柏叶片总含水量、自由水和自由水／束缚水的比值均较高，而脯氨酸和可溶性糖含量较低；在休眠季节（冬季）刚好相反，在低温胁迫下，圆柏属植物通过叶片渗透调节物质（脯氨酸和可溶性糖）含量的增加和水分含量以及总含水量、自由水和自由水／束缚水的比值的下降，降低组织细胞的渗透势，提高其保水和抗胁迫能力，增强抗冻性，两种圆柏属植物叶片水分和代谢积累物的差异分析表明：祁连圆柏之所以比圆柏更能忍受极端低温冷冻环境，可能与脯氨酸的大量积累有关，因此，脯氨酸的积累可能是在极端环境条件下生长的植物的特征之一。

英文摘要：

In this paper, the seasonal changes of leaf metabolites in Sabina przewalskii and Sabina chinensis, two evergreen woody plants, were observed during their adaptation process of frost. The observation results show that the relative water, free water and ratio of free water/bound warer in the leaves of the two Sabina trees are higher in the growth season （summer）, with lower proline and soluble sugar contents. In dormancy season （winter）, the situation is just the opposite. Under low temperature stress, the two Sabinas enhance their frost tolerance by increasing osmoregulation substances （proline and soluble sugar） contents, decreasing the water content and changing the relative water, free water and ratio of free water/ bound water. Consequently there are able to reduce cell osmotic potential and maintain their water and improve anti-stress ability. It is also found, by analyzing the two Sabina leaves water and ,the differences in accumulation of metabolic, that Sabina przewalskii is better than Sabina chinensis for enduring the extreme cold environment. It is attributed to the accumulation of proline. Therefore, the accumulation of proline is possibly one of the characteristic substances in plants under an extreme environmental condition.