Water status modelling: impact of local rainfall variability in Burgundy (France)

Understanding the physiological and molecular bases of grapevine responses to mild to moderate water deficits is fundamental to optimize vineyard irrigation management and identify the most suitable varieties. In Mediterranean regions, the higher frequency of heat waves and droughts highlights the importance of precision irrigation to meet vine water demands and demonstrates the necessity for a deeper understanding of the different physiological responses among varieties under water stress. In this context, previous reports show an interplay between stomatal regulation of transpiration and changes in leaf hydraulic conductivity, also with the involvement of aquaporins (AQPs), particularly under water stress. However, how those signaling mechanisms are regulated in different grapevine varieties along phenological phases is unclear.

Three compounds, 3-mercaptohexanol (3MH), 3-mercaptohexyl-acetate (3MHA) and 4-mercapto-4-methylpentan-2-one (4MMP), also known as varietal thiols, have been identified to contribute positively to wine aroma and are responsible for the distinct gooseberry, grapefruit, guava and box tree character found in Sauvignon blanc wines. Certain volatile thiol compounds though, can cause off-aromas of onion, garlic, rubber and rotten egg, this group of molecules is known as reductive sulphur compounds (RSC). This study looks into how the addition of sulphur-compounds to Sauvignon blanc juice contributes to the varietal thiol (3MH and 3MHA) concentration and reductive sulphur compound concentration in South African Sauvignon blanc wine.

Despite their significant impact on wine quality and stability, colloids in red wine remain relatively under-researched. A series of studies, developed in the context of the d-wines project, aimed to provide a comprehensive understanding of the structure, composition, and formation mechanisms of red wine colloids by studying monovarietal wines from 10 of the most significant Italian red grape varieties. Starting from the idea that proteins, polysaccharides, and tannins should be involved in colloid formation, 110 monovarietal red wines were analysed for these components, revealing high inter- and intra-varietal diversity [1].

Global warming has enhanced the frequency and severity of drought events, hence calling for a better management of water resources in the vineyard and for an improvement of breeding platforms. Somatic embryogenesis (SE) (i.e. the initiation of embryos from somatic tissues) can spontaneously generate new genetic variability, which results from genetic mutations, changes in epigenetic marks, or phenotypic alterations.
This study was tailored to test whether vines in vitro regenerated through SE (i.e. somaclones), can tolerate water deprivation better than the mother plant.

Phenolic composition is essential to wine quality (Cleary et al., 2015; Bindon et al., 2020; Niimi et al., 2020) and its assessment is a strong industrial need to quality management.