关键词: 干旱应答元件结合蛋白质, 启动子, 顺式作用元件, 瞬时表达

Abstract: In order to analyze transcriptional regulative mechanism of GmDREB3 gene, the GmDREB3 promoter (1 648 bp) was isolated from soybean genome using SiteFinding-PCR method. The sequences is abundant in A/T base and predicted to contain a lot of putative cis-element, such as low-temperature responsive element (MYC), dehydration responsive element (MYB), ABA responsive element (ABRE), and so on, as well as TATA-box in biological database. To identify the key promoter regulative re-gion controlling gene expression, GmDREB3 promoter was truncated according to the prediction of putative cis-element and in-serted into the site upstream of GUS reporter gene. Then, vectors containing different length GmDREB3 promoters were trans-ferred into wheat callus by particle bombardment, and after different stress treatments, function of these putative cis-elements was analyzed by identifying activation of GUS using histochemistry staining and GUS fluorescence intensity analysis. The results indicated that the promoters between –285 and –1 648 bp (relative to the translational start site) activated expression of GUS re-port gene under drought and low temperature stresses. But only the promoter region between –285 and –1 117 bp could activate expression of maximal GUS gene in wheat callus. Another promoter region between –1 117 and –1 464 bp weakened the ability for activating expression of GUS gene under drought and low-temperature stress conditions. Thus, it was suggested that there are some positive regulating motif between –285 and –1 117 bp and negative regulating motif between –1 117 and –1 464 bp of GmDREB3 promoter. As a result, the expression of GmDREB3 gene can be kept in an appropriate level response to various stresses through the regulation of both positive and negative regulating motifs.

Key words: Dehydration responsive element binding protein, Promoter, Cis–element, Transient expression