Drought is the most important environmental stress limiting agricultural productivity and threatening world food security. Plants respond to drought stress by rapidly accumulating the phytohormone abscisic acid (ABA), which binds the PYR1/PYL/RCAR famliy of receptors to activate defense responses and inhibit growth.When the stress subsides,plants must cease the defense reponses rapidly activate mechanisms to promote growth and recovery.However,the mechanisms regulathing the physiological switch between these defense and groeth states in plants in plants have been unclear.