水稻OsNHX5基因的亚细胞定位及表达分析

Subcellular Localization and Expression of OsNHX5 in Rice

采用PCR方法从水稻中克隆出1个Na^+/H^+逆转运蛋白基因OsNHX5,构建了该基因的亚细胞定位表达载体,利用注射烟草法对OsNHX5进行亚细胞定位,利用荧光定量PCR技术研究OsNHX5基因在盐胁迫下的表达模式。结果表明,OsNHX5与拟南芥AtNHX5和AtNHX6的亲缘关系较近,该蛋白定位于细胞内膜系统上;荧光定量PCR结果表明,叶中OsNHX5基因的表达受KCl胁迫诱导上调表达,而根中OsNHX5基因的表达变化不明显。OsNHX5是一个细胞内膜系统上的K^+/H^+逆转运蛋白,可为耐盐水稻的分子育种提供理论依据。

Salt stress suppresses growth and development of rice. Cloning salt tolerant related genes in rice for analysis of their functions might lay a foundation for research in rice salt tolerance mechanism and for salinity resistance breeding. A Na^+/H^+ antiporter gene OsNHX5 was cloned from Oryza sativa by polymerase chain reaction (PCR) method, and its localization expressing vector was constructed and observed through tobacco injection mediated by Agrobacterium tumefaciens.The expression patterns of OsNHX5 under salinity were analyzed by using real-time PCR. Phylogenetic analysis revealed that OsNHX5 was homologous to Arabidopsis AtNHX5 and AtNHX6. The results showed that OsNHX5 protein was localized in the intracellular membranes. The OsNHX5 gene was induced by KCl stress and its expression was upregulated in leaves but was not significantly different in roots under NaCl or KCl stress. Our results illustrated that OsNHX5 was an endosomal K^+/H^+ antiporter, and this finding would give a theoretical basis for molecular breeding of salt tolerant rice in the future.