二穗短柄草(Brachypodium distachyon)BdAD1基因的克隆、表达及功能分析

本研究利用生物信息学结合RT-PCR技术从二穗短柄草(Brachypodium distachyon)中克隆出BdAD1的c DNA基因,该基因编码一个包含500个氨基酸残基的乙醛脱氢酶家族蛋白。系统进化关系分析表明,该BdAD1蛋白序列与小麦(Triticum aestivum)、羊草(Leymus chinensis)和大麦(Hordeum vulgare)的同源蛋白具有较近的亲缘关系。BdAD1基因在植物细胞的细胞核和细胞质中均有表达,而且BdAD1蛋白兼具松柏醛脱氢酶和芥子醛脱氢酶的活性(CALDH/SALDH),可将松柏醛与芥子醛分别酶解生成阿魏酸和芥子酸,但它对松柏醛的催化效率显著高于芥子醛,因此推测BdAD1可能在苯丙烷代谢途径中对阿魏酸的合成具有重要的调控作用。

Cloning,Expression and Functional Analysis of BdAD1 Gene from Brachypodium distachyon

The full-length cDNA of BdAD1 gene was isolated from Brachypodium distachyon using a method of RT-PCR combined with the bioinformatics.BdAD1 codes a protein of 500 amino acid residues that belongs to the aldehyde dehydrogenase family and has a high sequence homology with those from Triticum aestivum,Leymus chinensis and Hordeum vulgare.BdAD1 gene expresses in both cell nucleus and cytoplasm.It was revealed by HPLC that BdAD1 combines the catalytic activity of coniferylaldehyde dehydrogenase and sinapaldehyde dehydrogenase for it can hydrolyze coniferyl aldehyde and sinapic aldehyde into ferulic acid and sinapic acid,respectively,but its activity to coniferyl aldehyde is obviously higher than to sinapic aldehyde,indicating that BdAD1 might play an important regulating role to ferulic acid biosynthesis in phenylpropanoid pathway of plant.