rd29A启动子克隆及对低温响应的研究

Cloning cold-induced promoter rd29A and its responsibility to low temperature

研究从拟南芥(Arabidopsis thaliana)基因组DNA克隆了rd29A基因启动子,序列分析表明该启动子具有两个干旱、高盐和低温响应顺式作用元件(DRE),在851～856 bp碱基处为TATA box,其它主要调控区域也存在。然后,分别用rd29A启动子和CaMV 35S启动子,构建了具有绿色荧光蛋白(GFP)基因的植物表达载体pBIG和pBIRG。通过基因枪导入法转化洋葱表皮细胞,在25 ℃和4 ℃条件下培养16 h后,用荧光显微镜观察GFP基因的表达水平。结果表明,在低温条件下,rd29A启动子的活性明显高于CaMV 35S启动子,说明rd29A启动子是一低温诱导型启动子,可满足在低温条件下使目的基因在转基因植物中进行表达的目的。

Cold-induced promoter rd29A from Arabidopsis thaliana was cloned in the research. Sequencing analysis showed that there were two Dehydration -responsive Elements (DRE) and several other main regulation domains in this promoter and TATA box exist between 851～856 bp. Two plant expression vectors, pBIG with GFP gene drive by constitutive promoter CaMV 35S promoter and pBIRG with GFP gene controlled by rd29A, were constructed to essay the activity of both promoters. pBIG and pBIRG were delivered to epidermis cells of onion by particle bombardment. The transferred epidermis was cultured in room temperature and 4 ℃ respectively for 16 hr. The expression of GFP gene driven by different promoters in onion epidermis was observed with fluorescent microscope. The results showed that GFP gene driven by rd29A promoter expressed in a higher level than that controlled by CaMV 35S when cultured in low temperature (4 ℃).