Cotton leaf curl virus (CLCuV) belongs to the subgroup Ⅲ of geminiviruses with single strand DNA genome. Study demonstrated that the bidirectional promoter of CLCuV had activity in Agrobacterium tumefaciens (Smith et Townsend) Conn. This is the first report for the activity of the bidirectional promoter of geminivirus in A. tumefaciens . Results showed that the activity of the complementary sense promoter was stronger than that of virion sense promoter, and was detected 2-fold higher than that of CaMV 35S promoter in A. tumefaciens . Moreover, the promoter 5′ deletion analysis indicated that the mean GUS activity driven by a 287 nucleotides complementary sense promoter fragment (from -287 to the translation initiation site) is 4 times higher than that driven by the whole complementary sense promoter in A. tumefaciens . This result suggested that there might exist negative regulatory elements in this deleted fragment. The function of other cis- elements included in CLCuV complementary sense promoter was also discussed in this paper.
棉花曲叶病毒启动子在根癌土壤杆菌中的表达活性
谢迎秋*孟蒙* 徐鸿林 吴茜 陈蕾 朱祯**
（中国科学院遗传研究所，北京100101）
摘要：棉花曲叶病毒(CLCuV)是一种单链DNA病毒,属于双生病毒亚组Ⅲ.检测了双生病毒双向启动子在根癌土壤杆菌(Agrobacterium tumefaciens (Smith et Townsend) Conn)LBA4404中的活性,研究发现在根癌土壤杆菌中CLCuV双向启动子的互补链启动子活性高于病毒链启动子,其在土壤杆菌中驱动的GUS活性为CaMV 35S启动子驱动的GUS活性的2倍.同时,通过对一系列CLCuV双向启动子的互补链5′端缺失体在土壤杆菌中的活性分析表明-287 bp上游可能存在一负调控元件,该元件的缺失可使启动子活性达全长启动子的4倍之多.还讨论了CLCuV互补链启动子所包含的其他顺式元件的功能.
关键词： B-葡萄糖苷酸酶基因；棉花曲叶病毒；启动子；顺式元件
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