枸杞甜菜碱醛脱氢酶基因全长cDNA的克隆与表达分析

cDNA cloning and expression analysis of the BADH gene encoding a betaine aldehyde dehydrogenase in swordlike atractylodes rhizome(Lycium barbarum)

根据GenBank中的植物甜菜碱醛脱氢酶(BADH)基因的同源保守区设计简并引物,采用RT-PCR技术从枸杞中扩增出BADH基因的部分保守序列,并利用巢式PCR、5′-RACE和3′-RACE获得BADH基因的全长cDNA。测序结果表明:BADH全长为1 869 bp,包含1 512 bp长的开放读码框(ORF),编码1个含503个氨基酸残基、分子质量为55.12 ku、等电点(PI)为5.19,包括醛脱氢酶高度保守序列VTLELGGKSP和其后287 bp处与酶功能有关的Cys的假定蛋白质。mRNA分析表明:BADH基因在枸杞幼苗组织中受高盐胁迫和低温胁迫的上调诱导表达,表明该基因可能在植物抵御非生物胁迫中发挥重要作用。

The partial cDNA of betaine aldehyde dehydrogenase gene（BADH） was cloned from Lycium Barbarum through RT-PCR technique by specific primers designed on the basis of BADH gene on GenBank website.Moreover,a 1 869 bp full length cDNA sequence of BADH was obtained using nested PCR,5′-RACE and 3′-RACE technique.The cloned BADH cDNA contained an open reading frame（ORF） of 1 512 bp and was predicted to encode a deduced protein with 503 amino acid residues and a molecular weight of 55.12 ku.The deduced protein contained the conserved motif VSLELGGKSP of aldehyde dehydrogenase.The gene accession nucleotide sequence number in GenBank was FJ514799.Semi-quantitative RT-PCR assay revealed that BADH was significantly up-regulated in the swordlike atractylodes rhizome seedlings under salt or cold stress.The result suggests that BADH might play an important role in swordlike atractylodes rhizome responses to abiotic stress.