Abstract: The changes of membrane lipids and their fatty acids of rice seedlings were measured before and after low temperature stress. The results indicated that when the rice seedlings were sprayed with cholesterol,then stressed by low temperature,the reductions of LPC,PS,PG,linolenic acid (18:3) and IUFA and the additions of PA and palmitic acid (16:0) were less than those of the control both in leaves and roots. This result suggests that the sensitivity of rice seedlings to cold stress is closely related to PA and their unsaturated fatty acids component.Treating with exogenous cholesterol not only can prevent mernbrane lipids from chilling injuries but also enhance the cold re-sistance of rice seedlings.

Key words: Cholesterol, Membrane lipid, Fatty acid, Rice seedling, Cold resistance

摘要： 分析了水稻幼苗低温胁迫前后膜脂和膜脂脂肪酸含量变化。结果表明,经胆固醇处理的幼苗叶和根细胞膜脂中LPC、PS和PG含量比对照下降少,PA含量增加也较少。胆固醇处理的幼苗叶和根棕榈酸(16:0)增加量和亚麻酸(18:3)与IUFA减少量均明显比对照少。试验结果证明,水稻幼苗叶片和根系的抗冷力与PA含量和脂肪酸不饱和程度变化有密切关系。外源胆固醇处理水稻幼苗能阻止低温对膜脂的破坏作用,提高幼苗抗低温胁迫能力。

关键词: 胆固醇, 水稻幼苗, 膜脂, 脂肪酸, 抗冷力