Résumé
Aquaporins belong to a superfamily of membrane channels with members in all living organisms. In plants, aquaporins mediate a large part of the cell-to-cell and intracellular water movements. The ability of certain plant aquaporins homologues to transport nutrient such as boron or gas such as CO2 has recently been demonstrated. This present chapter specifically examines how our current understanding of aquaporin structure and function can be integrated into whole plant physiology. Expression studies coupled with physiological and genetic analyses have allowed to delineate a variety of functions for aquaporins in roots, leaves, and during plant reproduction. In addition, a large variety of molecular and cellular mechanisms have been identified that lead to fine regulation of membrane water transport, during plant development, or in response to environmental stimuli. However, central physiological questions remain, such as the role of aquaporins in carbon assimilation, or in a hydraulic control of growth and cell