Water-use process regulation by changing the drying and wetting method of plant root zones. The figure is modified from: Sauter A, Davis WJ, Hartung W. 2001. The long-distance abscisic acid signal in the droughted plant, the fate of the hormone on its way from root to shoot. Journal of Experimental Botany
52, 1991–1997, by permission of the Society for Experimental Biology, and Davies WJ, Sally W, Loveys BR. 2002. Stomatal control by chemical signalling and the exploitation of this mechanism to increase water use efficiency in agriculture. New Phytologist
153, 449–460, with permission.