Catalyzes the desaturation of both long- and medium-chain acyl-CoAs to 2-trans-enoyl-CoAs. Most active with C14-CoA. Activity on long-chain mono-unsaturated substrates is 40% higher than with the corresponding saturated substrates. Seems to be an important factor in the general metabolism of root tips. May be involved in the biosynthesis of jasmonic acid. a 2,3-saturated acyl-CoA + O2 = a (2E)-enoyl-CoA + H2O2 Binds 1 FAD per subunit. Homodimer. A number of isoforms are produced. According to EST sequences. Expressed mainly in flowers and young seedlings. Lower expression in roots, leaves and bracts. Induced by seed imbibition with a peak at day 2 and then declines to reach a basal level 4 days after sowing. Induced by dehydration, abscisic acid (ABA) and jasmonic acid (JA), and localy and systemically by wounding. Belongs to the acyl-CoA oxidase family.