GSE121146
Volatile profiles and transcriptomic variation in Cabernet Sauvignon grapes in response to various sunlight exposure strategies in a warm climate
Basal leaf removal has been widely practiced to increase cluster sunlight exposure, control berry rot and eventually improve grape berry quality. Early leaf removal performed in cool region appeared to benefit the accumulation of norisoprenoids and monoterpenes. However, effects of this canopy management and leaf moving on volatile profiles and transcriptome of grape berry in warm region characterized with strong sunshine and arid climate were paid less attention. To cope with multiple possible effects caused by global warming, researches in warm region are urgently needed to provide a guide for adjusting the sunlight exposure treatment to adapt the climate change.In Manas county of Xinjiang province, sunlight exposure treatments performed in this study resulted in decreased ß-carotene and lutein, which mainly responsible for the reduced norisoprenoids in ripening grapes. Substrate competition due to the up-regulation of VvTPS-a and VvNCED3 may contribute to the decreased concentration of monoterpenes in exposed berries. The notable increased C6 alcohols in the grape berries treated by leaf removal applied at veraison (LR-V), was mainly attribute to the enhanced substrate availability of linoleic acid and linolenic acid together with the higher expression of VvLOXO and VvADH1. Free C6 aldehyde was reduced by half leaf removal applied at veraison (HLR-V), leaf moving at veraison (LM-V) and leaf removal applied at berry pepper-corn size (LR-PS). Moreover, transcriptomic analysis indicated that both LR-V and LM-V treated grape berry implemented multiple stress-mitigation strategies to acclimate the improved sunlight exposure. Interestingly, photosynthesis-related genes in grape berry were primarily up-regulated by LR-V as a consequence of carbohydrate source removal rather than improved sunlight exposure. Weighted gene co-expression network analysis (WGCNA) suggested that the genes encoding malate synthase and 3-oxoacyl-(acyl carrier protein) reductase show a significant correlation with the accumulation of C6 alcohol. Overall design: Nine grape berry sample groups were used for RNA sequencing in this study, consisting of LR-V, LM-V and the control at the E-L 36, E-L 37 and E-L 38 stages, respectively.