甘蓝型油菜BnbHLH122基因的克隆、表达模式及胁迫响应分析

Cloning, expression pattern and stress responses analysis of BnbHLH122 genes in Brassica napus L.

摘要:

为了进一步探究甘蓝型油菜bHLH转录因子的生物学功能，本实验采用同源克隆技术从甘蓝型油菜中克隆了2个bHLH122转录因子基因全长cDNA序列，分别命名为：BnbHLH122-1（GenBank登录号为MT795160）和BnbHLH122-2（GenBank登录号为MT795161）.生物信息学分析表明，BnbHLH122-1和BnbHLH122-2蛋白为不稳定的亲水性蛋白，都含有bHLH保守结构域，分别与白菜和甘蓝中预测的bHLH122蛋白的亲缘关系最近.亚细胞定位和转录激活活性验证实验结果表明两个BnbHLH122蛋白均定位在细胞核且具备转录激活活性.qRT-PCR实验结果表明BnbHLH122-1基因主要在花期的根中表达，BnbHLH122-2基因主要在苗期的根和花期的花中表达.此外，高温、低温、干旱、高盐、渗透、核盘菌胁迫以及ABA、SA、MeJA激素处理均能显著影响BnbHLH122基因的表达，由此说明甘蓝型油菜BnbHLH122基因可能在维持植株正常的生长发育和抵御逆境胁迫过程中发挥重要调节作用.

Abstract:

In order to explore the biological function of bHLH transcription factors in Brassica napus L., two full-length cDNA sequences of bHLH122 transcription factor genes were cloned from Brassica napus L. by homologous cloning method and named BnbHLH122-1 (GenBank accession number: MT795160) and BnbHLH122-2 (GenBank accession number: MT795161) respectively. Bioinformatics analysis showed that both BnbHLH122 proteins were unstable hydrophilicity proteins with the bHLH conserved domain, which were closely related to the predicted bHLH122 proteins in Brassica rapa and Brassica oleracea, respectively. The results of subcellular localization and transcriptional activation verification showed that both BnbHLH122 proteins were located in the nucleus and had transcriptional activation activity. Then the qRT-PCR results showed that the BnbHLH122-1 gene is mainly expressed in the roots at the flowering stage, and the BnbHLH122-2 gene is mainly expressed in the roots at the seeding stage and flowers at the flowering stage. Besides, the expression of BnbHLH122 genes was significantly affected by the stresses of high temperature, low temperature, drought, salt, osmosis, Sclerotinia sclerotiorum and the hormone treatments of ABA, SA and MeJA, indicating that BnbHLH122 genes may play important roles in regulation in the progress of maintaining normal growth and development and resisting stresses in Brassica napus L..