Optimized protocol for high-quality RNA extraction from grape tissues using sorbitol pre-wash

In order to study the impact of climate change on Bordeaux grape varieties and to assess the adaptation capacities of candidates to the grape varieties of this wine region to the new climatic conditions, an experimental block design composed of 52 grape varieties was set up in 2009 at the INRAE Bordeaux Aquitaine center. Among the many parameters studied, the three main phenological stages of the vine (budburst, flowering and veraison) have been closely monitored since 2012. Observations for each year, stage and variety were carried out on four independent replicates. Precocity indices have been calculated from the data obtained over the 2012-2021 period (Barbeau et al. 1998). This work allowed to group the phenological behaviour of the grapevine varieties, not only based on the timing of the subsequent developmental stages, but also on the overall precocity of the cycle and the total length of the cycle between budburst and veraison. Results regarding the variability observed among the different grape varieties for these phenological stages are presented as heat maps.

Downy mildew, a disease caused by Plasmopara viticola (Berk. et Curt.) Berl. and De Toni, is one of the strongest threats to grapevine (Vitis vinifera L.) production. Recently, sources of resistance to downy mildew were identified among Caucasian germplasm. Among them, the Georgian variety Mgaloblishvili revealed a unique resistance mechanism. A genome wide association study (GWAS) allowed the identification of the genetic bases of Mgaloblishvili resistance, the loci Rpv29, Rpv30 and Rpv31. To dissect the three resistance loci, Mgaloblishvili genome was sequenced using PacBio HiFi reads and assembled.

High temperatures influence plant development and induce a large set of physiological responses at the leaf scale. Stomatal closure is one of the most observed responses to high temperatures. This response is commonly considered as an adaptive strategy to reduce water loss and embolism in the vascular system caused by the high evaporative demand.

Malbec is Argentina’s flagship variety, and it is internationally recognized for producing high-quality red wines. Fruit set rate is a major component in grapevine yield determination, and it is the outcome of multiple genetic and environmental interacting variables. Here, we characterized the reproductive performance of 25 Malbec clones grown under homogeneous conditions in a 23-years old experimental plot. We measured traits near flowering (like the number of flowers per inflorescence) and at harvest (including the number of berries per cluster and berry weight), during two consecutive seasons (2022 and 2023).

Malolactic fermentation (MLF)¹, the decarboxylation of L-malic acid into L-lactic acid, is performed by lactic acid bacteria (LAB). MLF has a deacidifying effect that may compromise freshness or microbiological stability in wines² and can be inhibited by fumaric acid [E297] (FA). In wine, can be added at a maximum allowable dose of 0.6 g/L³. Its inhibition with FA is being studied as an alternative strategy to minimize added doses of SO₂⁴. In addition, wine yeasts are capable of metabolizing and storing small amounts of FA and during alcoholic fermentation (AF).