用含有不同长度FaChitl基因启动子区域与GUS基因融合构建植物表达载体pFaChitlP—I、pFaChitlP-Ⅱ以及pFaChitlP-Ⅲ并分别对烟草进行转化,经真菌激发子、干旱、机械损伤以及乙烯等多种胁迫处理后测定GUS活性。启动子缺失分析实验结果显示,真菌激发子对FaChitl基因启动子所介导的GUS诱导表达效果最强,而机械损伤只能微弱地诱导GL靥基因表达;FaChitl基因启动子-651bp以内的序列均能介导GUS基因的诱导表达,同时-935bp与-233bp之间的区域是该启动子响应真菌激发子、乙烯以及机械损伤胁迫所必需的。表明FaChitl启动子是一个多胁迫诱导型启动子。
Activation of different promoter fragments by fungal elicitors, dehydration, mechanical wounding, and ethylene were analyzed in transgenic tobacco using transcriptional fusions of FaChitl 5' upstream sequences to the GUS reporter gene (promoter-GUS expression vectors were designated as pFaChitlP-I, pFaChitlP-II and pFaChitlP-III, respectively). Analysis of promoter deletion showed that the FaChitl promoter conferred the strongest induction of GUS activity in response to treatment with fungal elicitors, but the least induction in response to mechanical wounding; GUS activity could be induced in response to four stress treatments in leaves containing the 651 bp upstream of the FaChitl start codon, and the fragment between 935 bp and 233 bp upstream of the FaChitl start codon was sufficient to direct gene expression in response to fungal elicitors, ethylene, dehydration, and mechanical wounding. Results indicated that the FaChitl promoter was a multiple stress inducible promoter.