Tetralone-ABA enhances winter cold acclimation, reduces deacclimation, and delays budbreak in V. vinifera and V. hybrid grapevines

Cold stress during the dormant season significantly constrains the expansion of grape and wine industries in cool climate viticulture regions of North America and Eurasia. In this study, we systematically evaluated a novel product, tetralone-ABA, for its efficacy in enhancing cold hardiness and delaying budbreak. Our approach included year-round physiological monitoring, transcriptome examination using 3'RNA-seq, and in silico simulation. For the RNA-seq data collection, bud samples were gathered during each deacclimation assay conducted in the 2022-2023 dormant season. The first assay was conducted on early winter buds with 581.5 chilling hours (Utah model). The second assay was conducted on mid-winter buds with 978.5 chilling hours. The third assay was conducted on late winter buds with 1339.9 chilling hours. During each deacclimation assay, control buds and tetralone-ABA treated buds were collected on days 0, 3, 5, 7, and 14 for RNA-seq analysis. Three biological replicates were used for each deacclimation assay, timepoint, and treatment combination.