Genetic Insights into Stress Resilience via Enhancing Salinity Adaptation in Barley

Salinity stress is one of the major abiotic stresses that significantly impacts plant growth and performance. Therefore, this study investigated the role of foliar-applied ascorbic acid (AsA) at a concentration of 2 mM as a mitigative approach to salt stress in barley during its vegetative stage. The research aimed to elucidate the genetic responses induced by AsA that potentially confer enhanced tolerance to salinity. A controlled environment experiment was conducted, wherein barley plants were subjected to salt stress and treated with a foliar application of AsA. Natural phenotypic variation showed an increment for all agronomical traits after the foliar application of AsA compared to saline environment (control). Highly significant markers were detected by using a genome-wide association study (GWAS) that are associated with all of the studied traits, underscoring the protective role of AsA under salt stress. Furthermore, the study identified several novel stress-responsive genes influenced by AsA treatment, pointing to complex genetic networks underlying salt stress mitigation. For instance, the gene HORVU.MOREX.r3.2HG0199440 at position (622,219,977–622,220,459 bp) on 2H, which is annotated as V-type ATP synthase beta chain, helps to maintain cellular redox balance during stress conditions. This research paves the way for future work on the practical applications of AsA in agriculture, especially in breeding programs aimed at enhancing salt stress tolerance in barley and similar cereals.