Fine-tuning of ABI1/2 activity and stability by phosphorylation/dephosphorylation mechanisms

[EN] The core components of abscisic acid (ABA) signaling¿PYR/ PYL/RCAR ABA receptors, coreceptor clade A protein phosphatases 2C (PP2CAs), and SnRK2 kinases¿are essential for mediating plant responses to ABA. Mutants impaired in these components exhibit either strong ABA-insensitive (pyl or snrk2 mutants) or ABA-hypersensitive (pp2c mutants) phenotypes. The recent discovery of RAF-like kinases as upstream activators of SnRK2s has added another regulatory layer to ABA signaling.