玉米淀粉分支酶基因启动子的克隆与功能分析

Cloning and Functional Analysis of the Promoter of Maize Starch Branching Enzyme Gene

以玉米品种“吉糯1号”的基因组DNA为模板,通过PCR扩增得到玉米淀粉分支酶基因的启动子序列,克隆到pMD18-TVector上,经测序,该启动子大小为934bp。与已报道的序列比较仅有14个核苷酸发生改变,同源性为98.5%。用该启动子取代植物表达载体pBI121的35S启动子,与GUS基因编码区连接,构建成融合质粒pSBE-GUS。经农杆菌介导法转化烟草,获得了转基因植株。GUS活性检测结果表明,由该启动子序列引导的GUS基因能在种子中表达,而在其他组织中表达微弱或未表达,证实该启动子具有种子特异性表达的功能。

Using the genomic DNA of maize cuhivar＂ Jinnuo 1＂ as template, the SBE promoter was isolated by PCR and was cloned into pMD18-T Vector. The size of this promoter is 934bp. Only 14 nucleotides showed changes comparing to the reported sequence and homologous rate was 98.50%. To construct the SBE promoter-GUS chimera gene, the SBE promoter was then cloned into expression vector pBI121 to replace the 35S promoter, and inserted upstream of the GUS gene encoding region. We then introduced pSBE-GUS into tobacco by Agrobacterium mediation. Analysis of gus activity showed that the gus only expressed in seeds. This confirmed that the cloned promoter is a seed specific promoter.