Mainly expressed in leaves. Expressed at the flowering stage. Up-regulated early after infection with P.syringae carrying avrRpt2 (PubMed:8742710). Up-regulated by brassinolide, cold treatment, syringolin, P.infestans infection and, at a lower level, by salicylic acid (PubMed:17723251). Down-regulated by 2-aminoethoxyvinylglycine (AVG), high CO(2), isoxaben, and propiconazole treatments (PubMed:17723251). Belongs to the TRAFAC class TrmE-Era-EngA-EngB-Septin-like GTPase superfamily. AIG1/Toc34/Toc159-like paraseptin GTPase family. IAN subfamily.