The role of ion channels in light-dependent stomatal opening

Stomatal opening represents a major determinant of plant productivity and s tress management. Because plants lose water essentially through open stomat a, volume control of the pore-forming guard cells represents a key step in the regulation of plant water status. These sensory cells are able to integ rate various signals such as light, auxin, abscisic acid, and CO2. Followin g signal perception, changes in membrane potential and activity of ion tran sporters finally lead to the accumulation of potassium salts and turgor pre ssure formation. This review analyses recent progress in molecular aspects of ion channel regulation and suggests how these developments impact on our understanding of light- and auxin-dependent stomatal action.