Under water deficit conditions, plant transpiration (TR) is regulated by a decrease in stomatal conductance (gs), which reduces carbon assimilation, biomass production, and final yield. TR (water loss) is a key physiological trait used to estimate plant water status and could help determine plants’ water consumptive (higher TR) and water conservative (lower TR) behavior. Studying plants with contrasting traits under different conditions offers deeper insight into their behavior. In this study, we evaluated drought resilience traits in the cultivated tomato line M82 and two introgression lines (IL6-4 and IL4-1-18), which contain small genomic regions from the wild species Solanum pennellii. IL6-4 is characterized by high transpiration, while IL4-1-1 exhibits low transpiration. Plants were subjected to well-watered and gradual drought conditions followed by re-irrigation, and their transpiration, stress degree, recovery, water use efficiency, water potential, and yield were evaluated. IL6-4 showed a higher drought stress degree during water deficit than IL4-1-1. However, IL6-4 recovered more rapidly upon re-irrigation and achieved a higher yield than both M82 and IL4-1-1 under drought conditions. However, IL4-1-1 showed higher WUEb under water stress than IL6-4. It is often assumed that high-transpiring plants are more drought-sensitive, while low-transpiring plants save water and recover better after re-irrigation. Our results challenge this view, showing that although IL6-4 experienced greater drought stress and physiological trade-offs, it recovered faster and ultimately achieved higher yields than M82 and IL4-1-1 under water stress. This suggests high transpiration, despite its costs under drought, can speed recovery and increase yield under fluctuating water availability.
