Acts as a negative regulator of abscisic acid (ABA) responses. Interacts with ICR1 (PubMed:17493810). Binds to SPK1 (PubMed:18308939). Although this sequence has a C-terminal -CXXX, it is palmitoylated at Cys-205, rather than prenylated. Belongs to the small GTPase superfamily. Rho family.