Oxidizes nonanal, propionaldehyde and acetaldehyde in vitro, in the following decreasing order of reactivity: nonanal, propionaldehyde, acetaldehyde. an aldehyde + H2O + NAD(+) = a carboxylate + 2 H(+) + NADH Measured at pH 9.5 for all experiments. By abscisic acid (ABA) and dehydration. Belongs to the aldehyde dehydrogenase family.