Fung Raymond W M, Gonzalo Martin, Fekete Csaba, Kovacs Laszlo G, He Yan, Marsh Ellen, McIntyre Lauren M, Schachtman Daniel P, Qiu Wenping
Department of Agriculture, Missouri State University, Mountain Grove, MO 65711, USA.
Plant Physiol. 2008 Jan;146(1):236-49. doi: 10.1104/pp.107.108712. Epub 2007 Nov 9.
Grapevines exhibit a wide spectrum of resistance to the powdery mildew fungus (PM), Erysiphe necator (Schw.) Burr., but little is known about the transcriptional basis of the defense to PM. Our microscopic observations showed that PM produced less hyphal growth and induced more brown-colored epidermal cells on leaves of PM-resistant Vitis aestivalis 'Norton' than on leaves of PM-susceptible Vitis vinifera 'Cabernet sauvignon'. We found that endogenous salicylic acid levels were higher in V. aestivalis than in V. vinifera in the absence of the fungus and that salicylic acid levels increased in V. vinifera at 120 h postinoculation with PM. To test the hypothesis that gene expression differences would be apparent when V. aestivalis and V. vinifera were mounting a response to PM, we conducted a comprehensive Vitis GeneChip analysis. We examined the transcriptome at 0, 4, 8, 12, 24, and 48 h postinoculation with PM. We found only three PM-responsive transcripts in V. aestivalis and 625 in V. vinifera. There was a significant increase in the abundance of transcripts encoding ENHANCED DISEASE SUSCEPTIBILITY1, mitogen-activated protein kinase kinase, WRKY, PATHOGENESIS-RELATED1, PATHOGENESIS-RELATED10, and stilbene synthase in PM-infected V. vinifera, suggesting an induction of the basal defense response. The overall changes in the PM-responsive V. vinifera transcriptome also indicated a possible reprogramming of metabolism toward the increased synthesis of the secondary metabolites. These results suggested that resistance to PM in V. aestivalis was not associated with overall reprogramming of the transcriptome. However, PM induced defense-oriented transcriptional changes in V. vinifera.
葡萄对白粉菌（PM），即葡萄白粉菌（Erysiphe necator (Schw.) Burr.）表现出广泛的抗性谱，但关于其对白粉菌防御的转录基础知之甚少。我们的显微镜观察表明，与感白粉病的酿酒葡萄‘赤霞珠’叶片相比，白粉菌在抗白粉病的夏葡萄‘诺顿’叶片上产生的菌丝生长较少，且诱导出更多褐色表皮细胞。我们发现，在没有真菌的情况下，夏葡萄中的内源水杨酸水平高于酿酒葡萄，并且在接种白粉菌后120小时，酿酒葡萄中的水杨酸水平升高。为了验证在夏葡萄和酿酒葡萄对白粉菌产生反应时基因表达差异会很明显这一假设，我们进行了全面的葡萄基因芯片分析。我们检测了接种白粉菌后0、4、8、12、24和48小时的转录组。我们在夏葡萄中仅发现3个对白粉菌有反应的转录本，在酿酒葡萄中发现625个。在感染白粉菌的酿酒葡萄中，编码增强病害易感性1、丝裂原活化蛋白激酶激酶、WRKY、病程相关蛋白1、病程相关蛋白10和芪合酶的转录本丰度显著增加，表明基础防御反应被诱导。酿酒葡萄对白粉菌有反应的转录组的总体变化也表明代谢可能重新编程以增加次生代谢物的合成。这些结果表明，夏葡萄对白粉菌的抗性与转录组的整体重新编程无关。然而，白粉菌在酿酒葡萄中诱导了以防御为导向的转录变化。
