Li Hai-Yan, Wei Wei, Li Yu
Institute of Mycology, Jilin Agricultural University, Changchun 130118, China.
Acta Biochim Biophys Sin (Shanghai). 2006 Jan;38(1):46-52. doi: 10.1111/j.1745-7270.2006.00126.x.
A salicylic acid (SA)-inducible VCH3 promoter was recently identified from grapevine (Vitis amurensis) that contains two inverse SA-responsive cis-acting elements and four W-boxes. To further demonstrate the roles of these elements, four fragments with lengths from -1187, -892, -589, -276 to +7 bp were fused with the b-glucuronidase (GUS) reporter gene and transferred to Nicotiana tobacum, together with another four VCH3 promoter fragments with mutation in the two inverse SA-responsive elements. The functions of each promoter fragment were examined by analysis of GUS activity in the transgenic tobacco root treated with SA. Enhanced GUS activity was shown in the roots of transgenic tobaccos with the VCH3 (-1187)-GUS construct containing two SA-responsive cis-acting elements and four W-boxes. However, GUS activity directed by the VCH3 (-892)-GUS construct, containing one SA cis-acting element and four W-boxes, was reduced by up to 35% compared with that in tobaccos transformed with the VCH3 (-1187)-GUS construct, indicating that the SA cis-acting element plays an important role in SA induction of the VCH3 promoter. Neither the m2VCH3 (-1187)-GUS nor the mVCH3 (-892)-GUS construct, with mutation on the SA-responsive elements, abolished the expression of GUS activity, demonstrating that the W-boxes in the VCH3 promoter are also involved in SA induction. Histochemical analysis of GUS activity directed by each of the eight VCH3 promoter fragments showed that GUS was expressed specifically in vascular tissue. It was concluded that both the SA-responsive cis-acting elements and the W-boxes are important for the SA induction of the VCH3 promoter. This promoter might have a potential use in plant genetic engineering.
最近从葡萄(山葡萄)中鉴定出一种水杨酸(SA)诱导型VCH3启动子,它含有两个反向SA响应顺式作用元件和四个W盒。为了进一步证明这些元件的作用,将长度分别为-1187、-892、-589、-276至+7 bp的四个片段与β-葡萄糖醛酸酶(GUS)报告基因融合,并与另外四个在两个反向SA响应元件中发生突变的VCH3启动子片段一起转入烟草。通过分析用SA处理的转基因烟草根中的GUS活性来检测每个启动子片段的功能。含有两个SA响应顺式作用元件和四个W盒的VCH3(-1187)-GUS构建体的转基因烟草根中显示出增强的GUS活性。然而,与用VCH3(-1187)-GUS构建体转化的烟草相比,含有一个SA顺式作用元件和四个W盒的VCH3(-892)-GUS构建体指导的GUS活性降低了35%,这表明SA顺式作用元件在SA诱导VCH3启动子中起重要作用。SA响应元件发生突变的m2VCH3(-1187)-GUS和mVCH3(-892)-GUS构建体均未消除GUS活性的表达,这表明VCH3启动子中的W盒也参与SA诱导。对八个VCH3启动子片段各自指导的GUS活性进行组织化学分析表明,GUS在维管组织中特异性表达。得出的结论是,SA响应顺式作用元件和W盒对于SA诱导VCH3启动子都很重要。该启动子可能在植物基因工程中有潜在用途。