Fondazione Edmund Mach, Research and Innovation Center, Via E,Mach 1, 38010 San Michele all'Adige, Italy.
BMC Plant Biol. 2011 Aug 12;11:114. doi: 10.1186/1471-2229-11-114.
Downy mildew, caused by the oomycete Plasmopara viticola, is a serious disease in Vitis vinifera, the most commonly cultivated grapevine species. Several wild Vitis species have instead been found to be resistant to this pathogen and have been used as a source to introgress resistance into a V. vinifera background. Stilbenoids represent the major phytoalexins in grapevine, and their toxicity is closely related to the specific compound. The aim of this study was to assess the resistance response to P. viticola of the Merzling × Teroldego cross by profiling the stilbenoid content of the leaves of an entire population and the transcriptome of resistant and susceptible individuals following infection.
A three-year analysis of the population's response to artificial inoculation showed that individuals were distributed in nine classes ranging from total resistance to total susceptibility. In addition, quantitative metabolite profiling of stilbenoids in the population, carried out using HPLC-DAD-MS, identified three distinct groups differing according to the concentrations present and the complexity of their profiles. The high producers were characterized by the presence of trans-resveratrol, trans-piceid, trans-pterostilbene and up to thirteen different viniferins, nine of them new in grapevine.Accumulation of these compounds is consistent with a resistant phenotype and suggests that they may contribute to the resistance response.A preliminary transcriptional study using cDNA-AFLP selected a set of genes modulated by the oomycete in a resistant genotype. The expression of this set of genes in resistant and susceptible genotypes of the progeny population was then assessed by comparative microarray analysis.A group of 57 genes was found to be exclusively modulated in the resistant genotype suggesting that they are involved in the grapevine-P. viticola incompatible interaction. Functional annotation of these transcripts revealed that they belong to the categories defense response, photosynthesis, primary and secondary metabolism, signal transduction and transport.
This study reports the results of a combined metabolic and transcriptional profiling of a grapevine population segregating for resistance to P. viticola. Some resistant individuals were identified and further characterized at the molecular level. These results will be valuable to future grapevine breeding programs.
由卵菌 Plasmopara viticola 引起的霜霉病是最常见的酿酒葡萄品种 Vitis vinifera 的严重疾病。然而，已经发现一些野生葡萄物种对这种病原体具有抗性，并被用作将抗性导入 V. vinifera 背景的来源。芪类化合物是葡萄中的主要植物抗毒素，其毒性与其特定化合物密切相关。本研究旨在通过对整个种群叶片的芪类化合物含量进行分析，并对感染后抗性和易感个体的转录组进行分析，评估 Merzling×Teroldego 杂交种对 P. viticola 的抗性反应。
对该种群对人工接种的三年分析表明，个体分布在从完全抗性到完全易感性的九个类别中。此外，使用 HPLC-DAD-MS 对种群中芪类化合物的定量代谢组学进行分析，确定了根据存在浓度和其图谱复杂性而不同的三个不同组。高产者的特征是存在反式白藜芦醇、反式白皮杉醇、反式 pterostilbene 和多达十三种不同的葡萄素，其中九种是葡萄中的新化合物。这些化合物的积累与抗性表型一致，表明它们可能有助于抗性反应。使用 cDNA-AFLP 进行的初步转录组学研究选择了一组在抗性基因型中被卵菌调节的基因。然后通过比较微阵列分析评估了这些基因在后代种群的抗性和易感基因型中的表达。发现一组 57 个基因仅在抗性基因型中被特异性调节，表明它们参与了葡萄与 P. viticola 的不亲和相互作用。这些转录本的功能注释表明，它们属于防御反应、光合作用、初级和次级代谢、信号转导和运输等类别。
本研究报告了对一个分离出对 P. viticola 抗性的葡萄种群进行代谢和转录组联合分析的结果。鉴定了一些抗性个体，并在分子水平上进一步进行了表征。这些结果将对未来的葡萄育种计划有价值。
