Involved in lignin biosynthesis. May catalyze the final step specific for the production of lignin monomers, like coniferyl alcohol, sinapyl alcohol and 4-coumaryl alcohol. (E)-cinnamyl alcohol + NADP(+) = (E)-cinnamaldehyde + H(+) + NADPH Binds 2 Zn(2+) ions per subunit. Aromatic compound metabolism; phenylpropanoid biosynthesis. Homodimer. Expressed in roots, first internodes and panicles. Expressed in the vascular bundles and sclerenchyma cells below the epidermis in leaves and stems. Reduced lignin content, late heading time, semi-dwarf and flexible culm. Belongs to the zinc-containing alcohol dehydrogenase family.