Résumé
In plants, ion transport systems play essential functions for cellular responses to the environment. An important example of this role is the regulation of leaf transpiration through the stomata pore, a process involved in drought tolerance. The regulation of the stomata pore aperture depends on molecular properties of the ion transporters and channels. Several classes of ion channels are present in stomata, and among them, we focused on the plant-specific Aluminum-activated malate transporters (ALMTs) family. This family is involved in crucial physiological functions of land plants and, in Arabidopsis thaliana, its members are localized at the plasma or vacuolar membrane. The vacuolar ALMTs mediate malate and chloride transport regulating stomata aperture and in the regulation of the plant cell metabolism. This family of membrane proteins presents a unique folding with specific biophysical properties. We used a combination of approaches to link the structural and functional characteristics of vacuolar ALMTs with their functions in vivo.