Duan Dong, Halter David, Baltenweck Raymonde, Tisch Christine, Tröster Viktoria, Kortekamp Andreas, Hugueney Philippe, Nick Peter
Molecular Cell Biology, Botanical Institute 1, Karlsruhe Institute of Technology, Kaiserstr. 2, 78133 Karlsruhe, Germany
Métabolisme Secondaire de la Vigne, UMR 1131, INRA, Université de Strasbourg, 28 rue de Herrlisheim, F-68021 Colmar, France.
J Exp Bot. 2015 Jun;66(11):3243-57. doi: 10.1093/jxb/erv137. Epub 2015 Apr 6.
Stilbenes, as important secondary metabolites of grapevine, represent central phytoalexins and therefore constitute an important element of basal immunity. In this study, potential genetic variation in Vitis vinifera ssp. sylvestris, the ancestor of cultivated grapevine, was sought with respect to their output of stilbenes and potential use for resistance breeding. Considerable variation in stilbene inducibility was identified in V. vinifera ssp. sylvestris. Genotypic differences in abundance and profiles of stilbenes that are induced in response to a UV-C pulse are shown. Two clusters of stilbene 'chemovars' emerged: one cluster showed quick and strong accumulation of stilbenes, almost exclusively in the form of non-glycosylated resveratrol and viniferin, while the second cluster accumulated fewer stilbenes and relatively high proportions of piceatannol and the glycosylated piceid. For all 86 genotypes, a time dependence of the stilbene pattern was observed: piceid, resveratrol, and piceatannol accumulated earlier, whereas the viniferins were found later. It was further observed that the genotypic differences in stilbene accumulation were preceded by differential accumulation of the transcripts for chalcone synthase (CHS) and stilbene-related genes: phenylalanine ammonium lyase (PAL), stilbene synthase (StSy), and resveratrol synthase (RS). A screen of the population with respect to susceptibility to downy mildew of grapevine (Plasmopara viticola) revealed considerable variability. The subpopulation of genotypes with high stilbene inducibility was significantly less susceptible as compared with low-stilbene genotypes, and for representative genotypes it could be shown that the inducibility of stilbene synthase by UV correlated with the inducibility by the pathogen.
芪类化合物作为葡萄重要的次生代谢产物，是主要的植保素，因此构成了基础免疫的重要元素。在本研究中，我们针对栽培葡萄的祖先野生葡萄（Vitis vinifera ssp. sylvestris）芪类化合物的产量及其在抗性育种中的潜在用途，探寻其潜在的遗传变异。在野生葡萄中鉴定出芪类化合物诱导性存在相当大的变异。研究显示了响应UV-C脉冲诱导产生的芪类化合物在丰度和谱型上的基因型差异。出现了两类芪类“化学变种”：一类变种芪类化合物快速且大量积累，几乎完全以非糖基化白藜芦醇和葡萄素的形式存在，而另一类变种积累的芪类化合物较少，且含有相对较高比例的云杉新苷和糖基化云杉新苷。对于所有86个基因型，均观察到芪类化合物谱型具有时间依赖性：云杉新苷、白藜芦醇和云杉新醇积累较早，而葡萄素则在较晚时出现。进一步观察发现，芪类化合物积累的基因型差异之前，查尔酮合酶（CHS）和芪类相关基因：苯丙氨酸解氨酶（PAL）、芪合酶（StSy）和白藜芦醇合酶（RS）的转录本存在差异积累。对该群体进行葡萄霜霉病（Plasmopara viticola）易感性筛选，发现存在相当大的变异性。与低芪诱导性基因型相比，高芪诱导性基因型亚群对霜霉病的易感性显著更低，并且对于代表性基因型而言，可以证明UV对白藜芦醇合酶的诱导性与病原体诱导性相关。
