Highest expression levels in young seedlings and much lower expression abundance in the later developmental stages. Down-regulated by aphid infection, 2-aminoethoxyvinylglycine (AVG), high CO(2), isoxaben, and propiconazole treatments. Up-regulated by brassinolides. Belongs to the TRAFAC class TrmE-Era-EngA-EngB-Septin-like GTPase superfamily. AIG1/Toc34/Toc159-like paraseptin GTPase family. IAN subfamily.