Comparative Phenotype and Transcriptome Profiling in Some Grapevine Cultivars in Response to Drought Stress

Drought is one of the main stress factors significantly affecting the growth, development and yield of agricultural crops. This study investigated the impact of drought stress on 30 grapevine genotypes. The cultivars were then ranked according to their degree of drought tolerance and classified as drought-tolerant, intermediately tolerant or sensitive. Phenotypic characteristics (NL, NR2 and LR2) were identified that can be used to determine the stress threshold. Using tran-scriptomic data from five cultivars with different levels of tolerance, differentially expressed genes (DEGs) were identified in control plants and in plants under stress, as well as DEGs between dif-ferent varieties when exposed to 2% mannitol. General patterns under drought stress were subsequently identified, including the activation of antioxidant defense systems and changes in the metabolism and biosynthesis of glucan, cellulose, polysaccharides, monocarboxylic acids, fatty acids and metal transport and splicing processes. It is hypothesised that drought tolerance is determined by increased expression of genes associated with glutathione metabolism and methylation processes.