Ethylene-responsive N-acetyltransferase required for differential cell elongation in the hypocotyl. Regulates apical hook formation of dark-grown seedlings. May control differential cell growth by regulating auxin activity. May be involved in negative feedback regulation of auxin homeostasis through the control of GH3-like genes. Modulates de novo shoot organogenesis. By ethylene. Unable to develop apical hook in the dark. Reduced length of dark-grown hypocotyls and reduced leaf initiation rate in light-grown seedlings. Belongs to the acetyltransferase family.