Direct receptor competition gates RGL2 proteolysis for seed germination timing in Arabidopsis

ABSTRACT: Seed germination is orchestrated by antagonistic gibberellin (GA) and abscisic acid (ABA) signals converging on the master germination repressor RGL2. Here, we unveil a receptor-competition paradigm where ABA receptors (PYLs) stabilize RGL2, both through direct physical interaction and through functional sequestration of DWA1, the CUL4-DDB1 E3 ligase substrate adaptor mediating RGL2 ubiquitination. GA receptors (GID1s) counteract this stabilization by competitively displacing PYLs from RGL2, leveraging their superior binding capacity to license DWA1-mediated degradation. Crucially, this competition is defined by the concentration of abscisic acid and gibberellin as they regulate PYL and GID1 expression. Genetic epistasis confirms that PYLs act upstream of DWA1, competing directly with GID1

SUBMITTER: Kaili Nie 

PROVIDER: S-SCDT-10_1038-S44318-026-00704-4 | biostudies-other |

REPOSITORIES: biostudies-other