Plants adapt to their ever-changing environment via positive and negative signals induced by environmental stimuli.Drought stress,for instance,induces accumulation of the plant hormone abscisic acid(ABA),triggering AB...Plants adapt to their ever-changing environment via positive and negative signals induced by environmental stimuli.Drought stress,for instance,induces accumulation of the plant hormone abscisic acid(ABA),triggering ABA signal transduction.However,the molecular mechanisms for switching between plant growth promotion and stress response remain poorly understood.Here we report that RAF(rapidly accelerated fibrosarcoma)-LIKE MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE 22(RAF22)in Arabidopsis tha/iana physically interacts with ABA INSENSITIVE 1(ABl1)and phosphorylates ABl1 at Ser416 residue to enhance its phosphatase activity.Interestingly,ABl1 can also enhance the activity of RAF22 through dephosphorylation,reciprocally inhibiting ABA signaling and promoting the maintenance of plant growth under normal conditions.Under drought stress,however,the ASA-activated OPEN STOMATA1(OST1)phosphorylates the Ser81 residue of RAF22 and inhibits its kinase activity,restraining its enhancement of ABl1 activity.Taken together,our study reveals that RAF22,ABl1,and OST1 form a dynamic regulatory network that plays crucial roles in optimizing plant growth and environmental adaptation under drought stress.展开更多
基金supported by grants from the National Science Foundation of China(31730007 and 31921001)。
文摘Plants adapt to their ever-changing environment via positive and negative signals induced by environmental stimuli.Drought stress,for instance,induces accumulation of the plant hormone abscisic acid(ABA),triggering ABA signal transduction.However,the molecular mechanisms for switching between plant growth promotion and stress response remain poorly understood.Here we report that RAF(rapidly accelerated fibrosarcoma)-LIKE MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE 22(RAF22)in Arabidopsis tha/iana physically interacts with ABA INSENSITIVE 1(ABl1)and phosphorylates ABl1 at Ser416 residue to enhance its phosphatase activity.Interestingly,ABl1 can also enhance the activity of RAF22 through dephosphorylation,reciprocally inhibiting ABA signaling and promoting the maintenance of plant growth under normal conditions.Under drought stress,however,the ASA-activated OPEN STOMATA1(OST1)phosphorylates the Ser81 residue of RAF22 and inhibits its kinase activity,restraining its enhancement of ABl1 activity.Taken together,our study reveals that RAF22,ABl1,and OST1 form a dynamic regulatory network that plays crucial roles in optimizing plant growth and environmental adaptation under drought stress.
