Copper amine oxidase that can use putrescine and spermidine as substrates. an aliphatic amine + H2O + O2 = an aldehyde + H2O2 + NH4(+) Binds 1 copper ion per subunit (By similarity). Can also use zinc ion as cofactor (By similarity). Contains 1 topaquinone per subunit. Binds 1 Mn(2+) ion per subunit. Amine and polyamine degradation; putrescine degradation. Homodimer. Expressed in roots, leaves and cotyledons. In young seedlings, expressed in hydathodes of new emerging leaves and cotyledons as well as in columella cells (PubMed:31862580). Also observed in hypocotyl/root junction, hypocotyls and in root apex (PubMed:31862580). Induced transiently by auxin (IAA) (PubMed:31862580). Induced during wounding, dehydration recovery, and treatment with putrescine (Put) (PubMed:31862580). Slightly and transiently repressed by jasmonic acid (MeJA), abscisic acid (ABA) and salicylic acid (SA), and drought (PubMed:31862580). Topaquinone (TPQ) is generated by copper-dependent autoxidation of a specific tyrosyl residue. Belongs to the copper/topaquinone oxidase family.