Abstract: Under low temperature conditions, seeds of hybrid rice Ⅱyou 6078 were treated with cholesterol at low concentrations. Results showed that cholesterol enhanced SOD and CAT activities, raised heat stable protein content and decreased MDA content. There was no obvious change in POD activity. ATP was mainly located in chloroplastid and mitochondria. The protection to chloroplastid of cholesterol was more effective than that to mitochondria and cytosol.

Key words: chilling stress, cholesterol, protection enzyme activity, malondialdehyde, adenosine triphosphate, heat stable protein, rice

摘要： 低浓度的胆固醇处理水稻种子，可增强冷害水稻幼苗的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性，降低丙二醛（MDA）含量，提高可溶性蛋白总量中的热稳定蛋白含量，但过氧化物酶（POD）活性变化不明显。亚细胞组分测定表明，ATP主要存在于叶绿体和线粒体中，胆固醇对低温下叶绿体的保护作用尤为明显。

关键词: 冷胁迫, 胆固醇, 保护酶活性, 丙二醛, 三磷酸腺苷, 热稳定蛋白, 水稻