北美海蓬子甜菜碱醛脱氢酶基因的克隆及表达载体构建

以北美海蓬子种子为材料, 采用RACE技术获得北美海蓬子BADH基因的cDNA全长序列. 结果表明: BADH基因cDNA全长为1836bp, 其中开放阅读框(ORF)为1503bp, 编码500个氨基酸, 预测蛋白的分子量为54.5kDa, 理论等电点为5.31. 推测出BADH氨基酸中含有甜菜碱醛脱氢酶家族高度保守的十肽序列(VTLELGGKSP)及与酶功能相关的半胱氨酸残基(Cys). 序列比对和系统进化树显示, 北美海蓬子与盐节木和盐穗木的亲缘关系最近, 同源性达94%. 并构建了植物表达载体pCAMBIA3301-BADH, 将其成功导入到农杆菌EHA105中, 为进一步研究该基因的功能奠定了基础.

Cloning of Gene from Salicornia bigelovii and its Expression Vectors Construction

A full length cDNA sequence of BADH gene was cloned by RACE from Salicornia bigelovii seeds. The results show that the full length cDNA of BADH gene is 1836bp, which contains 1503bp ORF and encoded 500 amino acid with a putative molecular mass of 54.5 kDa and an isoionic point of 5.31.The deduced amino acid sequence contains the conserved decapeptide sequence (VTLELGGKSP) and cysteine residue in betaine aldehyde dehydrogenase. Sequence comparison and phylogenetic tree analysis reveal that Salicornia bigeloviiwas is close to Halocnemum strobilaceum and Halostachys caspica with 94% amino acids similarity. The plant expression vector pCAMBIA3301-BADH is successfully constructed, and the constructed vector is then transformed into Agrobacterium EHA105. The research is expected to lay a foundation for the further study on function of BADH gene.