In enzymology, a xanthoxin dehydrogenase (EC 1.1.1.288) is an enzyme that catalyzes the chemical reaction. Xanthoxin + NAD+ rightleftharpoons abscisic aldehyde + NADH + H+ Thus, the two substrates of this enzyme are xanthoxin and NAD+, whereas its 3 products are abscisic aldehyde, NADH, ...