部分缺失的棉花曲叶病毒互补链基因启动子具有超强活性

Partial Deleted Complementary Sense Gene Promoter from Cotton Leaf Curl Virus Shows Super Strong Promoter Activity

棉花曲叶病毒 (CLCuV)互补链基因启动子是一种新近鉴定的启动子 ,它能驱动外源基因在植物体内高效表达。为了研究其最佳启动子区域 ,对启动子 5′端进行了一系列缺失 ,得到 5种不同长度的启动子片段与GUS基因融合的植物表达载体。继而导入根癌农杆菌 ,采用叶盘法转化烟草 ,并检测转基因植株的GUS活性。实验结果表明 ,自启动子 5′端缺失至翻译起始位点上游 2 87、 2 71时启动子活性分别是全长启动子的 5倍、3倍。首次对棉花曲叶病毒互补链基因启动子的功能区进行了分析比较 ,发现缺失负调控元件的启动子比全长启动子具有更强的活性 ,平均活性是CaMV 35S启动子的 12倍 ,暗示该启动子具有应用潜力。

Complementary sense promoter from cotton leaf curl virus(CLCuV)is a novel promoter and could direct high level expression of foreign genes in transgenic plants. To determine the optimal promoter sequence for gene expression, CLCuV promoter was deleted from its 5′end to form promoter fragments with five different lengths and chimeric GUS genes were constructed using the promoter deletion. These vectors were delivered into Agrobacterium and tobacco plants were transformed by leaf discs method. GUS activity of transgenic plants was measured. The results showed that GUS activity with the promoter deleted to 287, 271 from the translation initiation site was respectively about five and three fold of that full length promoter. In this paper, the functional domains of complementary sense gene promoter of CLCuV were firstly compared. It was found that the promoter activity with the deletion of negative cis elements was much stronger than that of the f0ull length promoter and was about twelve fold in average than that of CaMV 35S promoter, suggesting that the promoter has great application potential.