Trehalose-6-Phosphate Promotes Growth, Yield, and Recovery After Pre-Flowering Drought Stress in Adzuki Bean (Vigna angularis)

Trehalose-6-phosphate (T6P) is involved in the regulation of plant growth and stress-related responses; however, its potential role in post-drought recovery remains unclear in legume crops. This study evaluated whether foliar application of native T6P could improve growth, yield formation, and physiological recovery in adzuki bean after pre-flowering drought stress. We aimed to propose a model for the production and drought tolerance regulation in adzuki bean. A three-year field experiment was conducted by applying T6P at both the budding stage and the initial pod stage. The plant architecture, yield, photosynthetic characteristics, defensive enzyme activity, sugar metabolism and hormone changes were evaluated. The results indicated that T6P significantly increased root, stem and leaf parameters in adzuki bean it also increased all yield traits except for the main stem branches and sections during post-drought recovery. Indeed, the yield per block of 5μM and 10μM of T6P application during post-drought recovery increased by 20.66% and 31.60% on average compared to the control under well-watered conditions and by 47.68% and 60.20% under drought stress during the three experimental years. Foliar T6P treatment was associated with higher antioxidant enzyme activities and related gene expression, lower ROS accumulation and proline content, and changes in sugar- and hormone-related traits during post-drought recovery. Therefore, foliar application of T6P at the budding and initial pod stages improved growth, yield formation, and post-drought recovery in adzuki bean. The result provide a novel strategy for T6P application for coordinating the high production potential and crop resilience.