Function
Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction. Involved in the abscisic acid (ABA) and ethylene signaling pathways. Regulates basipetal transport of auxin (IAA) in roots and hypocotyls, and thus modulates root architecture (e.g. lateral root formation). The heterotrimeric G-protein controls defense responses to necrotrophic and vascular fungi probably by modulating cell wall-related genes expression; involved in resistance to Plectosphaerella cucumerina.