Unraveling the complexity of high-temperature tolerance by characterizing key players of heat stress response in grapevine

The study conducted various fermentations of different grape juices using various strains of Lachancea thermotolerans and one strain of Saccharomyces cerevisiae. Because of the new conditions caused by climate change, wine acidity must be influenced as well as the volatile profile. Non-Saccharomyces yeasts such as L. thermotolerans are real options to mitigate the impact of climate change in wine production.

The appearance of the Phylloxera pest in the 19th century in Europe caused dramatical damages in grapevine diversity. To mitigate these losses, grapevine growers resorted to using crosses of different Vitis species, such as 110 Richter (110R) (V. berlandieri x V. rupestris), which has been invaluable for studying adaptations to stress responses in vineyards. Recently, a high quality chromosome scale assembly of 110R was released, but the available gene models were predicted without using as evidence transcriptional sequences obtained from roots, that are crucial organs in rootstock, and they may express certain genes exclusively. Therefore, we employed RNA sequencing reads of 110R roots under different stress conditions to predict new gene models in each haplotype of 110R under different stresses.

The effects of climate change in viticulture are currently a major concern, with heat waves and drought affecting yield, wine quality, and in extreme cases, even plant survival. Ancient grapevine varieties have high intravarietal genetic variability that so far has been explored successfully to improve yield and must quality. Currently, there is little information available on intravarietal variability regarding responses to stress. In the current work, the intravarietal genetic variability of several Portuguese varieties was studied for yield, must quality, and tolerance to abiotic stress, through indirect, rapid, and nondestructive measurements carried out in the field.

Climate emergency is going to affect the agricultural suistainability, wine grapes being probably one of the crops more sensitive to environmental constraints. In this context, mitigation strategies such as the revalorization of agricultural wastes are paramount to cope with the current challenges. The use of organic mulches has been reported to reduce soil water evaporation and improve vine water status, reduce soil erosion, and increase soil organic matter with little impact on berry quality. However, less is known about their effects on the microbiote of vineyards.

Many works have been carried out to identify the key aroma volatile compounds of oak wood (e.g., whisky-lactone, furfural, maltol, eugenol, guaiacol, vanillin) using conventional gas chromatography coupled with olfactometry and mass spectrometry (GC-O-MS). Inspired by recent untargeted approaches in the field of food “omics”, this work aims to extend our knowledge on the impact of cooperage process on the volatile composition of oak wood using two-dimensional comprehensive gas chromatography coupled with time of flight mass spectrometry (GCxGC-ToFMS).