Root-enriched β-amylase GmBAM-like 1 enhances drought and salt tolerance in Arabidopsis

Water scarcity impacts soybean cultivation and productivity globally. The ability of plants to withstand drought stress involves complex molecular and physiological mechanisms that facilitate the restoration and maintenance of cellular homeostasis. This study identified genes associated with carbohydrate metabolism and GABA shunt pathway that respond to water deficit in two soybean varieties. These varieties exhibited contrasting responses to water scarcity, and were subjected to two distinct cropping systems. In the drought-tolerant variety, a strategy for conferring tolerance was observed through the pre-emptive priming of the drought response. By applying multivariate analysis, we identified a pivotal gene, GmBAM-like 1, which responds to water scarcity. GmBAM-like 1 encodes a β-amylase and showed rapid activation and elevated expression levels in root tissues of the tolerant variety, suggesting its potential involvement in the drought tolerance response. Transgenic Arabidopsis plants overexpressing GmBAM-like 1 demonstrated enhanced tolerance to salt and osmotic stress, as evidenced by increased survival and germination rates. Additionally, after drought stress, these plants showed higher transpiration rates, larger leaf area, and greater relative water content upon rehydration. These findings demonstrate the potential of integrating the GmBAM-like 1 gene into plant breeding programs to develop cultivars with improved tolerance to water, salt, and osmotic stresses.