西伯利亚白刺质膜Na^+/H^+逆向转运蛋白基因NsSOS1的分离及表达分析

Isolation and Expression Analysis of Plasmalemma Na^+/H^+ Antiporter Gene from Nitraria sibirica

采用同源克隆技术分离了西伯利亚白刺(Nitraria sibirica)质膜Na^+/H^+逆向转运蛋白基因NsSOS1,并对其在不同胁迫条件下的表达特性进行了分析。NsSOS1包含3 516bp开放阅读框(ORF),编码1 171个氨基酸,蛋白分子量为128.34kD。生物信息学分析显示,NsSOS1包含12个跨膜结构域,具有植物SOS1蛋白的保守结构域。系统发育分析表明,NsSOS1与其他植物质膜Na^+/H^+逆向转运蛋白处于同一个次级分化群,与锦葵科海滨锦葵KvSOS1亲缘关系较近。实时荧光定量RT-PCR分析显示,NsSOS1基因在西伯利亚白刺的根和叶中表达量较高;其表达受到非生物胁迫(NaCl、低温、干旱)和外源激素(MeJA和GA)的诱导,表明NsSOS1基因在西伯利亚白刺抵御逆境胁迫过程中发挥重要作用。

The plasmalemma Na+/H+antiporter gene was isolated from Nitraria sibirica,referred to as NsSOS 1,using homology-based cloning techniques,and its expression characteristics under different stress conditions were investigated.The NsSOS 1 contains an open reading frame(ORF)of 3 516 bp,encodes a protein of 1 171 amino acids with a molecular weight of 128.34 kD.Bioinformatics analysis indicated that the NsSOS1 protein contains 12 transmembrane domains and functional domains conserved in plant SOS1 proteins.Phylogenetic analysis showed that the NsSOS1 belongs to the same clade to plasmalemma Na+/H+antiporters from the other plants and has a close relationship with the KvSOS1 of Malvaceae Kosteletzkya virginica.Quantitative real-time RT-PCR showed that the NsSOS 1 majorly expressed in roots and leaves of the N.sibirica and its expression levels were regulated by abiotic stress(NaCl,low temperature,drought)and exogenous hormones(MeJA and GA),suggesting that the NsSOS 1 gene plays an important role in resisting stress in N.sibirica.