The phytohormone abscisic acid (ABA) is an important regulator in plant abiotic stress adaptation. The control of the co-receptor PP2C proteins like ABI1 is the central hub of ABA signaling transduction. Under standard conditions, ABI1 binds to the protein kinase SnRK2s and inhibits their activities. ABA binding to receptor proteins PYR1/PYLs competes with SnRK2s in ABI1 targeting, and thus releasing SnRK2s and activating ABA response.
Click here for original story, Scientists reveal novel regulation mechanism of abscisic acid co-receptor ABI1 by E2-E3 complex UBC27-AIRP3
Source: Phys.org