结球甘蓝SET基因家族鉴定与表达分析

Genome-wide identification and expression analysis of SET domain-containing gene family in Brassica oleracea

植物SET基因是一类含有SET结构域的高度保守的基因家族,参与调控植物多种生命过程。为探讨结球甘蓝SET基因家族及其表达情况,采用生物信息学方法对SET基因家族进行鉴定,并利用实时荧光定量PCR(q RT-PCR)和半定量PCR(RT-PCR)对SET基因在不同组织中的表达模式进行分析。结果鉴定出28个结球甘蓝SET基因,它们不均匀分布在除1号染色体外的其他8条染色体上,编码蛋白的相对分子质量在29.20~185.16 kDa之间,预测等电点在5.02~9.06之间。基因结构分析表明结球甘蓝SET基因有0~23个内含子。系统进化分析将该家族成员分为7个亚族,其中第Ⅱ和第Ⅴ亚家族成员最多。在7个亚家族中,每个家族挑选1个基因,q RT-PCR结果显示选取的7个SET基因在结球甘蓝的叶片中不表达,而在根、茎、花蕾和花中均有表达,其中花蕾中表达量较高,进一步RT-PCR检测发现其在花粉母细胞时期高度表达。对结球甘蓝SET基因家族进行了鉴定,分析其进化关系和表达模式,可为深入研究该家族基因功能奠定一定的理论基础。

SET domain-containing gene is a highly conserved gene family with SET domain involved in the regulation of life processes in the plants. In order to investigate the SET gene family and its expression in cabbage(Brassica oleracea), the SET genes were identified by bioinformatics, and the expression patterns of these genes in different tissues were analyzed by qRT-PCR and RT-PCR. As results, a total of 28 SET domain-containing genes were identified from the cabbage genome, which were widely distributed on all chromosomes except for the first chromosome. The expected molecular weight of proteins ranged from 29.20 to 185.16 kDa, and the isoelectric point ranged from 5.02 to 9.06. The number of introns ranged from 0 to 23. Phylogenetic analysis showed that the SET domain-containing genes could be classified into seven subgroups, of which II and V subfamilies contained most members. The results of q RT-PCR revealed that seven representative SET domain-containing genes were consistently expressed in various tissues, including the roots, stems, buds and flowers, except for the leaves. The high expressions of seven genes were observed in pollens. Further study showed that the highest expression of these genes was manifested in most sporogenous cells during pollen mother cell stage. In conclusion, this study systematically investigated the structure, phylogenetic relationship and the expression pattern of SET domain-containing family genes of B. oleracea, which provides a theoretical foundation for the further functional analysis of SET domain-containing family genes in B. oleracea.