玉米ZmNAS1和ZmNAS2基因启动子的克隆与序列分析

根据已知玉米全基因组序列设计引物,采用PCR方法从基因组DNA中克隆两种玉米材料的Zm-NAS1和ZmNAS2基因启动子,利用生物信息学软件对启动子元件进行分析预测并比较在两种材料间差异。结果表明,ZmNAS1基因启动子在两种材料上差异明显,沈137较K12除一段574bp缺失外,他们之间还有24处单核苷酸多态性位点;两种材料间的ZmNAS2基因启动子无差异。ZmNAS1和ZmNAS2基因启动子均具有一些与光调控、激素诱导、响应逆境胁迫等有关的顺式作用元件,但数目存在一定差异;两个基因启动子上都有一定数目缺铁诱导元件的核心序列。根据启动子元件分析,初步判断ZmNAS1和ZmNAS2基因除受缺铁诱导表达外,还可能受到其他多种信号的共同调控,是一个复杂的调控过程。此外,ZmNAS1基因启动子在两种材料间差异明显,推测该基因在两种材料间受到的表达调控水平也不相同。

Cloning and Sequence Analysis of the Promoters of ZmNAS1 and ZmNAS2 Genes in Maize

PCR reactions were carried out to clone promoters of ZmNAS1 and ZmNAS2 from genomic DNA using primers designed according to the whole genome sequence of maize. And then, cis-acting elements and the differences of the promoters between two cultivars(K12 and Shen137) of maize were analyzed by bioinformatics software. The results showed that compared to cultivar K12, Shen137 was lack of 574 bp sequences in its promoter, besides existed 24 SNPs. However, the promoters of ZmNAS2 had no difference between the two cultivars of maize. There were some cis-acting elements relevant to light regulating, hormone inducing and stress responding in promoters of ZmNAS1 and ZmNAS2 genes, and core sequences in elements associated with the iron-deficiency-response were also identified. According to the analysis of promoter elements, we make a pre-judgement that expression and regulation of ZmNAS1 and ZmNAS2 were a complex process, and the two genes were regulated by several signals besides iron-deficiency stress. In addition, the promoters of ZmNAS1 are significantly different in the two cultivars, which indicated that the expression and regulation of ZmNAS1 between the two cultivars are not same.