甘蓝型油菜BnDHAR基因的克隆及表达分析

Molecular cloning and expression analysis of BnDHAR in Brassica napus L.

在甘蓝型油菜矮化突变体与其高秆亲本构建的消减杂交文库中,得到一长约230bp与编码脱氢抗坏血酸还原酶的DHAR基因核苷酸序列相似的DNA片段.采用同源克隆技术,在甘蓝型油菜中获得该基因的全长cDNA序列,命名为BnDHAR.BnDHAR与已公布的甘蓝型油菜基因组中的该基因核苷酸序列完全一致.对BnDHAR基因不同发育时期组织的表达分析的结果显示,BnDHAR基因在高秆油菜苗期的叶中表达量最高,是矮化突变体的5倍,在根、茎中表达极低,具有组织特异性.非生物胁迫显著影响BnDHAR表达,高温胁迫使其表达升高,盐胁迫处理9h时达最高,而干旱胁迫时表达量在处理12h时才达最高.

A 230bp partial DHAR-like DNA segments was obtained from a Subtractive hybridization li- brary of a dwarf mutant vs its wild-type parent in Brassica napus L.. A full-length cDNA sequence of the gene, namely BnDHAR, was cloned by homologous cloning from Brassica napus. BnDHAR was fully consistent with nucleotide sequence of the gene in the published Brassica napus genome. The BnDHAR gene expression in different organizations at different developmental stages of Brassica napus was analyzed by qRT-PCR technology. The results showed that BnDHAR gene expression in the wild- type leaves was the highest, almost 5- fold that in the dwarfing mutant, and extremely low expression in roots and stems. High temperature stress elevated the expression of BnDHAR. Under salt stress, BnDHAR reached its highest expression after treatment in 9h, whereas, the highest expression was de- tected after 12 hours treated with drought stress. In summary, the BnDHAR gene expression exhibited tissue specificity and probably played a role in response to abiotic stress in Brassica napus.