College of Horticulture, Northwest A & F University, Yangling, Shaanxi 712100, China.
J Exp Bot. 2011 May;62(8):2745-61. doi: 10.1093/jxb/erq447. Epub 2011 Apr 18.
The gene encoding stilbene synthase (STS) plays a central role in many biochemical and physiological actions, and its metabolite resveratrol possesses broad-spectrum resistance to pathogens, as well as diverse pharmacological properties, notably an anticancer effect. Here, we report the expression analysis of the gene encoding STS and its promoter function from a powdery mildew (PM)-resistant Chinese wild Vitis pseudoreticulata, and compare it with two PM-susceptible cultivated grapevines, Vitis vinifera cvs. Carignane and Thompson Seedless. We show an unusual expression pattern of STS in V. pseudoreticulata, which differs markedly from that of the cultivated species. Sequence comparisons reveal that the genomic DNA sequences encoding STS in the three grapevines are highly conserved, but a novel residue mutation within the key motif of STS is solely present in V. pseudoreticulata. Moreover, the STS promoter in V. pseudoreticulata displays a significantly different structure from that found in the two V. vinifera. The three promoter-driven GUS differential expression patterns in transformed tobacco plants induced with Alternaria alternata, methyl jasmonate, and wounding indicated that the structurally different STS promoter of V. pseudoreticulata is responsible for its specific regulatory function. We also demonstrate that the expression of STS genes from their native promoters are functional in transformed tobacco and retain pathogen inducibility. Importantly, the genomic DNA-2 of V. pseudoreticulata under its native promoter shows good induction and the maximum level of resveratrol content. These findings further our understanding of the regulation of STS expression in a resistant grapevine and provide a new pathogen-inducible promoter system for the genetic improvement of plant disease resistance.
编码芪合酶（STS）的基因在许多生化和生理作用中起着核心作用，其代谢产物白藜芦醇对病原体具有广谱抗性，以及多种药理学特性，特别是抗癌作用。在这里，我们报告了一种抗白粉病（PM）的中国野生葡萄（Vitis pseudoreticulata）中 STS 基因及其启动子功能的表达分析，并将其与两种易感 PM 的栽培葡萄（Vitis vinifera cvs。Carignane 和 Thompson Seedless）进行了比较。我们展示了 V. pseudoreticulata 中 STS 的异常表达模式，与栽培种明显不同。序列比较表明，三种葡萄中编码 STS 的基因组 DNA 序列高度保守，但 STS 关键基序内的一个新残基突变仅存在于 V. pseudoreticulata 中。此外，V. pseudoreticulata 中的 STS 启动子结构与在两个 V. vinifera 中发现的启动子结构有很大的不同。用Alternaria alternata、茉莉酸甲酯和创伤处理转化的烟草植物中三个启动子驱动的 GUS 差异表达模式表明，V. pseudoreticulata 结构不同的 STS 启动子负责其特定的调控功能。我们还证明，转化的烟草中来自其天然启动子的 STS 基因的表达是有功能的，并保留了病原体的诱导性。重要的是，V. pseudoreticulata 的基因组 DNA-2 在其天然启动子下表现出良好的诱导性和白藜芦醇含量的最大值。这些发现进一步加深了我们对抗性葡萄中 STS 表达调控的理解，并为植物抗病性的遗传改良提供了一种新的病原体诱导启动子系统。
