Specifically cleaves olefinic bonds in alpha,beta-unsaturated carbonyls and may be involved in detoxification or modification of these reactive compounds. May be involved in the biosynthesis or metabolism of oxylipin signaling molecules. In vitro, reduces 9R,13R-12-oxophyodienoic acid (9R,13R-OPDA) to 9R,13R-OPC-8:0, but not 9S,13S-OPDA, the natural precursor of jasmonic acid. Also reduces N-ethylmaleimide and maleic acid. NADP(+) + OPC-8 = (10Z,15Z)-12-oxophytodienoate + H(+) + NADPH The highest catalytic efficiency was observed with N-ethylmaleimide. Lipid metabolism; oxylipin biosynthesis. Constitutively expressed in roots, leaves, cotyledons, cells culture and to a lower extent in flowers. Seems to not be influenced by wounding. Belongs to the NADH:flavin oxidoreductase/NADH oxidase family.