Genetic manipulation of abscisic acid receptors enables modulation of water use efficiency.

The phytohormone abscisic acid (ABA) is a key signal molecule for controlling stomatal movement and stress responses such as drought. Genetic manipulation of ABA receptors has recently been reported to improve plant water use efficiency (WUE). We therefore compared details of WUE traits between the ABA receptor quintuple mutant and wheat ABA receptor-overexpressing Arabidopsis lines. Biomass and seed productivities per liter of water were both reduced in the receptor mutant but improved in the transgenic Arabidopsis lines. This result suggests that appropriate modulation of ABA receptors can extend crop potential productivity.