白菜DBB基因家族的鉴定与表达分析

Identification and Expression Analysis of DBB Family Genes in Brassica rapa

DBB基因在开花调控、根系生长、光形态建成、种子萌发、果实发育、逆境胁迫等生物学过程中发挥重要作用,但在白菜中还未有关于DBB基因的报道。本研究通过生物信息学方法鉴定到18个白菜DBB基因,其蛋白分子量为11285.63~35796.93D,理论等电点介于4.66~9.35之间,外显子数量为2~5个;大多数成员N端都含有保守结构域B-box1和B-box2,精氨酸和亮氨酸是在所有成员中都保守的氨基酸残基;该家族基因不均匀分布于白菜10条染色体上,多数基因出现基因复制,产生2个以上同源基因;多数基因与拟南芥DBB基因具有线性对应关系。顺式作用元件分析表明白菜DBB基因启动子上含有大量的光、厌氧、激素、低温等响应元件。组织特异性表达分析发现多数基因在不同组织中的表达水平与根类似;Bra032441在花中的表达水平显著高于其它成员。此外,绝大多数白菜DBB基因对盐胁迫有不同程度的响应。这些结果为后续解析DBB基因在白菜中的生物学功能奠定了基础。

DBBs play an important role in plant flowering regulation,root growth,photomorphogenesis,seed germination,fruit development and abiotic stress response.However,DBB gene family has not been identified in Brassica rapa.In this study,18 DBB genes were identified by bioinformatics method.The molecular weight was 11285.63~35796.93 D,the theoretical isoelectric point ranged from 4.66 to 9.35,and the number of exons ranged from 2 to 5;The N-terminus of most members contained the conserved domains B-box1 and B-box2,and the arginine and leucine were found as the most conserved amino acid in all DBBs.The DBBs were distributed unevenly on 10 chromosomes,and most of the genes were duplicated,producing more than 2 homologous genes.Most of the genes had linear correspondence with Arabidopsis DBB genes.The cis-element analysis showed that the DBB gene promoter contained a large number of light,anaerobic,hormonal and low temperature response elements.Tissue expression analysis showed that the expression level of most genes in different tissues was similar to that in the roots,interestingly,the level of Bra032441 in flowers was remarkably higher than that in other members.In addition,most of the DBBs in Brassica rapa respond to salt stress.These results laid a foundation for further analysis of the biological functions of DBB genes in B.rapa.