The impact of acetaldehyde on phenolic evolution of a free-SO₂ red wine

Mannoproteins are macromolecules found on the surface of yeast cells, composed of hyperbranched polysaccharide negatively charged chains by mannosyl-phosphate groups, fixed to a protein core. during the alcoholic fermentation and aging on lees, these mannoproteins are released from the yeast cell wall and become the main yeast-sourced polysaccharide in wine. due to their techno-functional properties, commercial preparations of mannoproteins can be used as additives to better assure tartaric and protein stability.

The ability of grapevine cultivars and rootstocks to cope with and adapt to recurring water constraints is the focus of this study. The contribution of intrinsic (epigenetic) and extrinsic (rootzone microbial community) factors to water stress resilience will be discussed. The study was conducted in a validated model vineyard where three scion cultivars (Pinotage, Shiraz, and Cabernet Sauvignon) on two rootstocks (Richter 110 and USVIT8-7) grow under recurring seasonal water constraint (and control) scenarios since planting (in 2020). Comprehensive profiling of the site, soil, atmospheric conditions, plants, and their physiological responses provide contextual data for the analyses conducted.

In the face of climate change, new grapevine varieties will have to show an adaptive phenotypic plasticity to maintain production with erratic water resources, and still ensure the quality of the final product. Their selection requires a better knowledge of the genetic basis of those traits and of the elementary processes involved in their variability. ‘PlastiVigne’, an emblematic project of the Vinid’Occ key challenge, funded by the Occitanie Region (France), tackles this issue with innovative genomic and physiological tools implemented on a unique panel of grape genetic resources representing the genetic diversity of Vitis vinifera. A graph-pangenome is developed from a representative set of high-quality genomes to study the extent and impact of structural genome variations and chromosomal rearrangements in the rapid adaptation capacity of grapevine.

The strategy of single berry phenotyping is a recently rediscovered research tool that has gained great attention. The latest studies have indicated that previous physiological models based on pooling asynchronous populations of berries provided biased or blurred information on berry development key players. The possibility of monitoring and sampling single synchronized berries to study their development sequentially has opened new lines of research aimed at unraveling the genes that regulate grapevine fruit development. This study aimed to decipher the gene pathways responsible for the activation/deactivation of physiological processes involved in the green phase of growth, the onset of ripening, and the second growth phase.

One of the main aspects of Climate Change is the increase of temperatures during summer and grape maturity period. Physiological processes are influenced by these high temperatures and result in grapes with higher sugar concentration, less acidity and less anthocyanin content among other quality changes. One strategy to deal with the climate change effects is the implementation of late winter pruning to alter the effect of high temperatures during key periods by delays in maturity time.