水稻细胞质铜锌超氧化物歧化酶基因的序列和表达分析

Sequence and Expression Analysis of Cytoplasmic Copper/zinc Superoxide Dismutase Gene in Rice

摘要:

以水稻(Oryza sativa)品种Cpslo17幼穗为材料，通过RT-PCR克隆了长度为698 bp的编码水稻细胞质铜锌超氧化物歧化酶基因(OsCu/Zn-SOD)。序列分析表明其覆盖基因完整编码框，编码由152个氨基酸组成的蛋白，它与玉米（Zea maize）Cu/Zn-SOD基因序列的相似率为88％。TargetP和ChloroP预测编码蛋白N端无信号肽序列，且此编码区段有8个外显子和7个内含子。利用Swiss-Model站点预测OsCu/Zn-SOD三维结构，并分析其铜锌离子结合位点的结构。RT-PCR结果表明OsCu/Zn-SOD在水稻不同品种均有表达，但表达量存在差异，OsCu/Zn-SOD在Cpslo17的分裂旺盛的幼嫩组织如幼穗、开花期花序和未成熟种子中表达量较高，而在叶片中表达量相对较低，在愈伤组织中表达微弱。

Abstract:

The 698 bp cytoplasmic copper/zinc-superoxide dismutase gene (OsCu/Zn-SOD) was cloned by RT-PCR from young panicles of rice Cpslo17, a wide-compatible rice cultivar (Oryza sativa). DNA sequence analysis indicated that the gene consisted of a full-open reading frame and encoded a protein of 152 amino acid residues. The nucleatide sequence of OsCu/Zn-SOD shares 88％ identity to maize Cu/Zn-SOD. No signal peptide was predicted by TargetP and ChloroP. Further analysis of encoding segment of OsCu/Zn-SOD revealed that it contained 8 exons and 7 introns. The putative three-dimensional structure of OsCu/Zn-SOD was predicted by the Swiss-Model server and Cu2+ and Zn2+ binding sites of OsCu/Zn-SOD were analyzed. RT-PCR results showed differential expression of OsCu/Zn-SOD in leavesof both japnica and indica rice. OsCu/Zn-SOD was expressed highly in panicles during young ear and the flowering stages or in immature seeds, however less in leaves and faintly in callus.