Luo Min, Gu Su-Hai, Zhao Shu-Hui, Zhang Fang, Wu Nai-Hu
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100080, China.
Acta Biochim Biophys Sin (Shanghai). 2006 Jun;38(6):393-402. doi: 10.1111/j.1745-7270.2006.00172.x.
As the sole ubiquitous signal small guanosine triphosphate-binding protein in plants, Rop gene plays an important role in plant growth and development. In this study, we focus on the relationship between the novel rice Rop gene OsRacB and plant salt tolerance. Results show that OsRacB transcription is highly accumulated in roots after treatment with salinity, but only slightly accumulated in stems and leaves under the same treatment. Promoter analysis showed that OsRacB promoter is induced by salinity and exogenous salicylic acid, not abscisic acid. To elucidate its physiological function, we generated OsRacB sense and antisense transgenic tobacco and rice. Under proper salinity treatment, sense transgenic plants grew much better than the control. This suggests that overexpression of OsRacB in tobacco and rice can improve plant salt tolerance. But under the same treatment, no difference could be observed between OsRacB antisense plants and the control. The results indicated that OsRacB is only an accessory factor in plant salt tolerance.
作为植物中唯一普遍存在的信号小GTP结合蛋白，Rop基因在植物生长发育中起重要作用。在本研究中，我们聚焦于新型水稻Rop基因OsRacB与植物耐盐性之间的关系。结果表明，盐处理后OsRacB转录本在根中高度积累，但在相同处理下在茎和叶中仅轻微积累。启动子分析表明，OsRacB启动子受盐度和外源水杨酸诱导，而非脱落酸。为阐明其生理功能，我们构建了OsRacB正义和反义转基因烟草及水稻。在适当的盐处理下，正义转基因植株生长状况远优于对照。这表明在烟草和水稻中过表达OsRacB可提高植物耐盐性。但在相同处理下，OsRacB反义植株与对照之间未观察到差异。结果表明，OsRacB仅是植物耐盐性中的一个辅助因子。
