胡杨超氧化物歧化酶基因家族耐逆境的分子机理研究

Molecular Mechanisms of Stress Tolerance of Superoxide Dismutase Gene Family in Populus euphratica

  • 摘要: 以已有基因组或转录物组数据的杨柳科树种为参考,采用生物信息学的常规方法,对胡杨SOD基因家族现状、同源关系、蛋白质三维结构及各家族成员对盐胁迫的响应等方面进行了较为系统的分析,以探索其分子水平的适应机理。结果表明:杨柳科树种基因组中SOD基因家族由Cu, Zn−SOD(CSD)、Mn−SOD(MSD)、Fe−SOD(FSD)3个亚家族组成,胡杨基因组中分别含有7、3、2个SOD基因亚家族成员,其中FSD3已被假基因化而失去功能,FSD1基因在胡杨叶组织中被高表达。MSD亚家族基因在胡杨和毛果杨的根和叶愈伤组织中均具有较高表达量,MSD1基因是盐胁迫条件下唯一持续上调的基因;MSD1(187K−T和202H−N)和MSD2(97R−N)3个氨基酸突变引起四聚体亚基间相互作用增强,使得2 种MSD亚型均具有较高的蛋白质稳定性,有利于蛋白质积累到较高的浓度。

     

    Abstract: In this study, we employed conventional bioinformatics methods to analyze the differences of current status, homology, protein three-dimensional structure and the expression regulation in response to salt stress among SOD subfamily members of Populus euphratica. The findings indicated that there are 3 SOD gene subfamilies in the genome of P. euphratica, including Cu, Zn−SOD (CSD), Mn−SOD (MSD), and Fe−SOD (FSD). The genome of P. euphratica contains 7, 3 and 2 SOD subfamily members, respectively. Among which FSD3 has been pseudogenized and lost its function. FSD1 gene is highly expressed in leaf tissue of P. euphratica. MSD subfamily genes were highly expressed in roots, leaves and callus of P. euphratica and P. trichocarpa. MSD1 gene, as the only gene that is continuously upregulated under salt stress. Three amino acid mutations of MSD1(187K−T and 202H−N) and MSD2(97R−N) could be lead to enhanced interactions between the subunits of the tetramer, making the 2 MSDs of P. euphratica have higher protein stability, which is beneficial for protein accumulation.

     

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