Copper amine oxidase that can use putrescine and spermidine as substrates (PubMed:23915037). Involved in putrescine catabolism in peroxisomes (PubMed:23915037). an aliphatic amine + H2O + O2 = an aldehyde + H2O2 + NH4(+) Amine and polyamine degradation; putrescine degradation. Mostly expressed in stems, and, at lower levels, in flowers and leaves (PubMed:23915037). Mainly detectable in stipules, hypocotyls and roots (PubMed:31862580). In young seedlings, expressed in hypocotyls, hypocotyl/root junctions and roots, especially in vascular tissue (e.g. xylem and metaxylem) (PubMed:31862580). Observed in shoot apex, associated with stipules (PubMed:31862580). Induced transiently by auxin (IAA) (PubMed:31862580). Induced by jasmonic acid (MeJA) (PubMed:23915037, PubMed:31862580). Accumulates during dehydration recovery and treatment with putrescine (Put) (PubMed:31862580). Repressed by abscisic acid (ABA) and salicylic acid (SA) (PubMed:31862580). Triggered by wounding (PubMed:23915037, PubMed:31862580). Topaquinone (TPQ) is generated by copper-dependent autoxidation of a specific tyrosyl residue. Belongs to the copper/topaquinone oxidase family. Truncated N-terminus.