Starch Metabolism and Stomatal Regulation Enhance Drought Resilience in Barley: An Integrated Multi-Omics Analysis.

Understanding the molecular mechanisms of drought tolerance in barley is crucial for food security. This study employed integrated transcriptomic and metabolomic analyses to investigate drought responses in tolerant (EC_S1) and sensitive (Baudin) barley. We identified key differentially expressed genes (DEGs) and metabolites (DEMs), highlighting genotype-specific strategies in stress adaptation. The drought-tolerant EC_S1 exhibited enhanced activation of pathways related to plant hormone signaling, antioxidant metabolism (e.g., glutathione), and energy mobilization. Functional characterization revealed that silencing HvGH14, a β-amylase gene, impaired maltose metabolism and osmotic adjustment, while silencing HvTPK1, a potassium channel gene, disrupted ABA-mediated stomatal closure. These findings elucidate the metabolic and transcriptional basis of drought tolerance in barley and provide potential genetic targets for improving crop resilience and sustainable agriculture.