Cinnamoyl-CoA reductase probably involved in the formation of phenolic compounds associated with the hypersensitive response. Seems not to be involved in lignin biosynthesis. (E)-cinnamaldehyde + CoA + NADP(+) = (E)-cinnamoyl-CoA + H(+) + NADPH Aromatic compound metabolism; phenylpropanoid biosynthesis. Expressed at low levels in leaves, stems and flowers. By the bacterial pathogen X.campestris. Belongs to the NAD(P)-dependent epimerase/dehydratase family. Dihydroflavonol-4-reductase subfamily.