甘薯油菜素内酯应答基因的克隆和表达分析

Cloning and Expression Analysis of Brassinosteroids Responsive Gene in Sweet Potato

为了解甘薯油菜素内酯(brassinosteroids,简称BR)应答基因BES1的功能及其在甘薯不同组织的表达特性,该研究利用甘薯(Ipomoea batatas L.)基因组数据库,筛选保守性较好的BES1基因序列设计引物,以甘薯品种‘广薯87’为模板进行PCR扩增,克隆出甘薯BES1基因(GenBank登录号为MH448304)。该基因长度为2 256 bp,编码322个氨基酸。系统进化树分析结果表明,BES1与番茄、芝麻的亲缘关系最近,其氨基酸序列具有高度保守的N末端结构域和PEST结构域。qRT-PCR分析表明,BES1基因在甘薯膨大期的块根表达量最高,而且受油菜素内酯的诱导表达,油菜素内酯浓度为10μmol/L时表达量最高。该结果为进一步研究甘薯BES1基因的功能奠定了基础,对甘薯的遗传改良与抗逆品种选育具有一定的参考价值。

In order to understand the function of the sweet potato brassinolide(BR) response gene BES1 and its expression characteristics in different tissues, we used the sweet potato(Ipomoea batatas L.) genomic library to screen the well-preserved BES1 gene sequence primers, and the genomic DNA of sweet potato variety ‘Guangshu 87’ was used as a template for PCR amplification. The sweet potato BES1 gene(GenBank accession number MH448304) was successfully cloned, and gene length is 2 256 bp, encoding 322 amino acids. Phylogenetic tree analysis showed that BES1 is closely related to that of tomato and sesame, and the amino acid sequence has a highly conserved N-terminal domain and PEST domain. qRT-PCR analysis showed that the expression of BES1 gene was the highest in the growth stage of sweet potato, and it was induced by phytohormone brassinolide. The expression was the highest when the concentration of BR was 10 μmol/L. The results laid a foundation for further study of the function of sweet potato BES1 gene, and had certain reference value for genetic improvement of sweet potato and breeding of resistant varieties.