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 the grapevine. The 30 cultivars were classified as drought-tolerant, intermediately tolerant or sensitive. The phenotypic characteristics the number of new leaves, the number of second-order roots and the length of second-order roots (NL, NR2 and LR2 respectively) were identified as the most sensitive biometric characteristics. These parameters can be used to determine the optimal level of stress exposure for plants. Using transcriptomic 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 different varieties when exposed to 2% mannitol. General patterns of gene expression 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 hypothesized that drought tolerance is determined by the increased expression of genes associated with glutathione metabolism and methylation processes.