Abstract: RACK1 is a scaffold protein with versatile functions,and plays important roles in the regulation of plant growth and development. Transgenic rice plants,of which the expression of RACK1 gene was inhibited using RNA interference (RNAi) approach,were used to study possible functions of RACK1 in the responses of rice to drought stress. Real-time PCR analysis showed that the expression of RACK1 in transgenic rice plants was inhibited more than 50%. The transgenic rice plants showed higher tolerance to drought stress as compared with the non-transgenic rice plants. The peroxidation of membrane and production of malondialchehyde were significantly lower,and the superoxide dismutase activity was significantly higher than those of the non-transgenic rice plants. It suggested that RACK1 negatively regulated rice tolerance to drought stress,which was related to redox system of rice plants.

Key words: Oryza sativa, RACK1 gene, RNA interference, transgenic plant, drought tolerance

摘要： RACK1是一种多功能支架蛋白，广泛参与植物生长发育过程的调节。利用RNA干涉技术抑制水稻RACK1基因的表达，分析了RACK1基因在响应干旱胁迫中的功能。实时定量PCR对获得的转基因植株的RACK1基因表达分析结果表明，转基因水稻RACK1基因表达受抑制程度达50%左右。与非转基因水稻（对照）相比，转基因水稻耐干旱能力显著强于对照，其膜的过氧化酶和丙二醛的产生显著低于对照，而超氧化物歧化酶活性极显著高于对照。表明RACK1蛋白质调节水稻对干旱胁迫的耐性，并且这种调节在很大程度上与植株体内的氧化还原系统有关。

关键词: 水稻, RACK1基因, RNA干涉, 转基因植株, 抗旱性