Grapevine and maize: Two guard cell shaped strategies to cope with repeated drought stress.

Adaptation of crops to recurrent drought stress is crucial for maintaining agricultural productivity and achieving food security under changing climate. Guard cells, pivotal regulators of plant water usage and assimilation, are central to this adaptation process. However, the metabolic dynamics of guard cells under drought stress remain poorly understood, particularly in grapevine, a prominent crop grown in arid regions, and maize, a staple crop with substantial water requirements. In this study, differences in guard cells metabolism during drought stress of grapevine and maize were investigated by performing physiological and metabolomic analyses. Metabolomic analysis highlighted differential responses in amino acids and sugars, with grapevine guard cells displaying greater stability in amino acid and sugar signatures, while maize showed marked increases in sugar levels. These findings suggest two distinct adaptive strategies, a vigorous acclimation of guard cells, as observed in maize, and an attenuated acclimation of guard cells, shown in grapevine. Understanding these metabolic adjustments is helpful for enhancing drought resilience in agricultural systems.