Molecular Characterization of Erysiphe necator (powdery mildew) resistance loci from the grapevine cultivar `Regent´ and their signaling network

葡萄藤品种Regent在15号染色体的基因座Ren 3处携带对白粉病的抗性。在该位点中，鉴定了四个候选基因。这些需要表征其功能，以确定介导抗性的基因。将详细研究它们的转录本（确定RNA的起始和结束、剪接变体）。将研究与GFP（绿色荧光蛋白）融合的编码蛋白在细胞中的定位。所有这些实验都将与E.接种和未接种的葡萄抗性和敏感葡萄藤植物。在第15号染色体上发现了一个额外的抗性位点Ren 9。它的序列需要分析那里编码的基因。随后，还必须表征这些候选基因的功能。目前已鉴定的候选抗病基因根据其分子结构编码感受白粉病释放的信号分子（效应子）的受体。受体和效应子之间的相互作用介导过敏反应（感染部位周围的局部细胞死亡）作为防御反应。触发植物各种防御途径的信号转导网络将通过比较敏感葡萄藤品种与丽晶的综合RNA-Seq实验来研究。该实验将提供关于在实验性接种白粉病孢子或模拟接种后的不同时间点活性的大多数基因的信息。不同活性的基因应该能够解决有关的信号通路。关键调控基因将被确定。利用分子标记对这些基因进行标记，可用于葡萄藤分子标记辅助育种。

The grapevine cultivar Regent carries resistance to Powdery Mildew on chromosome 15 at locus Ren3. In this locus four candidate genes were identified. These need to be characterized for their function to determine the gene that mediates resistance. Their transcripts will be investigated in detail (determination of start and end of RNA, splice variants). Encoded proteins will be studied in fusion with GFP (green fluorescent protein) in regard to their localization in the cell. All these experiments will be performed in comparison of E. necator inoculated and non-inoculated resistant and susceptible grapevine plants. An additional resistance locus Ren9 was found on chromosome 15. Its sequence needs to be analyzed for the genes encoded there. Subsequently, also these candidate genes have to be characterized for their function. The candidate resistance genes identified so far code for receptors sensing signaling molecules (effectors) released by powdery mildew according to their molecular structure. The interaction between receptor and effector mediates a hypersensitive response (a localized cell death around the infection site) as defense response. The network of signal transduction that triggers various defense pathways of the plant will be studied by a comprehensive RNA-Seq experiment comparing a susceptible grapevine cultivar to Regent. This experiment will deliver information on the majority of genes active at different time points following experimental inoculation with spores of powdery mildew or mock inoculation. Differentially active genes should enable to resolve the signaling pathways concerned. Key regulatory genes will be identified. They should be applicable to improve the breeders selection for durable resistance after tagging them with molecular markers for use in marker-assisted grapevine breeding.