甘蓝型油菜BnbHLH92基因的克隆与表达分析

Molecula cloning and expression analysis of BnbHLH92 genes in Brassica napus L.

摘要:

为研究甘蓝型油菜bHLH转录因子的功能, 采用同源克隆技术从甘蓝型油菜中克隆了5个BnbHLH92基因全长cDNA序列，分别命名为BnbHLH92-1、BnbHLH92-2、BnbHLH92-3、BnbHLH92-4、BnbHLH92-5，其编码区长度分别为738，657，684，741，717bp.qRTPCR实验表明，除BnbHLH92-1外，其它的BnbHLH92基因主要在抽薹期和花期的根中表达，BnbHLH92-1主要在抽薹期和花期的根以及二叶一心期的叶中表达.非生物胁迫显著影响BnbHLH92基因的表达，使其表达量升高.低温胁迫下，BnbHLH92基因分别在胁迫后4、6、6、6、6 h表达量达最高.高温胁迫下，5个BnbHLH92基因分别在胁迫后2、6、6、8、4 h表达量达最高.盐胁迫下，BnbHLH92基因分别在胁迫后 6、6、24 、24 、24 h表达量达最高.在ABA诱导下BnbHLH92基因表达量也有不同程度的增加，分析发现BnbHLH92基因的启动子序列上存在ABA响应元件（ABRE）.

Abstract:

To study the functions of bHLH TFs in Brassica napus, five fulllength cDNA sequences of BnbHLH92 genes are cloned from Brassica napus by the homologous cloning method and named as BnbHLH92-1, BnbHLH92-2, BnbHLH92-3, BnbHLH92-4, BnbHLH92-5, respectively. And the length of the coding region for each gene is 738, 657, 684, 741, 717 bp, respectively. The qRTPCR result shows that BnbHLH92-1 gene is expressed in the root of the bolting stage and flowering stage as well as the two leaves stage, but the other BnbHLH92 genes mainly expressed in the roots of the bolting stage and the flowering stage. The expression of BnbHLH92 genes is significantly affected by abiotic stress, which increases the amount of genes expression. The expression level of five BnbHLH92 genes reach its highest under a low temperature stress for 4, 6, 6, 6 and 6 h, under a high temperature stress for 2, 6, 6, 8 and 4 h, under a salt stress for 6, 6, 24, 24 and 24 h, respectively. The expression of each BnbHLH92 gene is also increased in different degrees under ABA induction. It is found that there is an ABA response element (ABRE) on the promoter sequence of each BnbHLH92 gene.