HighlightFunctional analysis of the four grapevine shikimate dehydrogenases (VvSDH1–4) reveals that two of them are involved in gallic acid biosynthesis.

Phenolic compounds represent a large family of plant secondary metabolites, essential for the quality of grape and wine and playing a major role in plant defense against biotic and abiotic stresses. Phenolic composition is genetically driven and greatly affected by environmental factors, including water stress. A major challenge for breeding of grapevine cultivars adapted to climate change and with high potential for wine-making is to dissect the complex plant metabolic response involved in adaptation mechanisms. A targeted metabolomics approach based on ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS) analysis in the Multiple Reaction Monitoring (MRM) mode has been developed for high throughput profiling of the phenolic composition of grape skins. This method enables rapid, selective, and sensitive quantification of 96 phenolic compounds (anthocyanins, phenolic acids, stilbenoids, flavonols, dihydroflavonols, flavan-3-ol monomers, and oligomers…), and of the constitutive units of proanthocyanidins (i.e., condensed tannins), giving access to detailed polyphenol composition. It was applied on the skins of mature grape berries from a core-collection of 279 Vitis vinifera cultivars grown with or without watering to assess the genetic variation for polyphenol composition and its modulation by irrigation, in two successive vintages (2014)(2015). Distribution of berry weights and δ 13 C values showed that non irrigated vines were subjected to a marked water stress in 2014 and to a very limited one in 2015. Metabolomics analysis of the polyphenol composition and chemometrics analysis of this data demonstrated an influence of water stress on the biosynthesis of different polyphenol classes and cultivar differences in metabolic response to water deficit. Correlation networks gave insight on the relationships between Pinasseau et al.Grapevine Polyphenols Response to Drought the different polyphenol metabolites and related biosynthetic pathways. They also established patterns of polyphenol response to drought, with different molecular families affected either positively or negatively in the different cultivars, with potential impact on grape and wine quality.

Highlights • Design of a novel Empore™ disk-based passive sampler to enable the deployment in well bore holes for groundwater monitoring. • Novel passive sampler used to monitor groundwater and stormwater runoff from infiltration systems. • Combination of passive sampling and liquid chromatography/high resolution mass spectrometry for groundwater and stormwater runoff screening. • Development of an analytical procedure based on a suspect screening workflow providing a rapid and comprehensive analysis. • Qualitative screening of polar pesticides and pharmaceuticals in impacted groundwater sites around Lyon, France.