Characterization of drought stress response via high-throughput metabolome profilling in Triticale

Drought stress is one of the most significant stress factors causing physiological, biochemical, and metabolic damage to plant phenotypes. In this study, the drought stress tolerance mechanisms of 13 different triticale varieties, primarily cultivated in Turkey and Italy, were evaluated in terms of physiological, biochemical, and metabolomic parameters and were comparatively related to their parents, wheat (♀) and rye (♂). Physiological parameters such as germination and coleoptile percentage, radicle and coleoptile length (cm), radicle number, flag leaf diameter (mm), plant height (cm), fresh weight (g), leaf number, flag leaf area, and stem diameter (cm) were assessed. Biochemical parameters, including proline, MDA, and antioxidant enzymes like SOD, CAT, and APX, were analyzed, along with metabolomic profiling to identify stress-related metabolites. Compared to the group not subjected to stress, drought stress was found to have adverse effects on physiological parameters. When exposed to abiotic stress, the levels of antioxidant enzymes increased in the plants. Under drought stress, all varieties showed an increase in total protein content as well as proline, MDA, SOD, CAT, and APX activity. Metabolomic profiling of triticale varieties under drought stress identified 45 metabolites, including sucrose, fructose, glutamine, L-asparagine, L-(-)-malic acid, L-alanine, serine, aspartic acid, D-glutamic acid, galactose, citric acid, glucose, asparagine, L-proline, glutamic acid, maltose, melibiose, and methionine, which were found to be associated with drought.