野生木薯中蔗糖合酶基因I的启动子克隆与调控区域鉴定

Promoter Cloning and Regulatory Domain Identification of Sucrose Synthase I Gene in Wild Cassava

克隆了野生木薯蔗糖合酶I基因的5′侧翼序列,发现其5′UTR区存在一个前导内含子,为了探究该基因启动子的调控区域以及前导内含子的可能功能,构建了6个侧翼序列梯度缺失载体并转化烟草。结果表明:野生木薯蔗糖合酶I基因的前导内含子可单独起始基因的转录,部分启动子序列的缺失会对基因的转录活性产生较大影响;不同缺失载体烟草转化株响应ABA的程度和方向存在差异,可能与ABA响应相关顺式作用元件的分布以及启动子序列与前导内含子的互作相关。该结果将会对木薯蔗糖合酶I基因的遗传改良提供理论指导。

The 5＇ flanking sequence of sucrose synthase I gene was cloned in a wild cassava, and a leader intron in its 5＇UTR. In order to explore the regulated domain of the promoter region and the possible function of leader intron, six deleted vectors were constructed and transformed into tobacco. The results showed that the leader intron of the wild cassava SuSyl gene could start gene transcription by itself, and the sequence deletion in promoter had great influence on the transcription activity of SuSyl gene. There were differences in magnitude and direction responding to ABA treatment among these transformed tobacco plants, it possibly caused by the distribution of ABA responsive cis-element, as well as the interactions between the regulated domains of promoter and the leader intron. In general, these results will provide theoretical guidance for genetic improvement of cassava SuSyl gene.