Catalyzes the irreversible reduction of the cytotoxic compound methylglyoxal (MG, 2-oxopropanal) to (S)-lactaldehyde as an alternative to detoxification of MG by glyoxalase I GLO1. MG is synthesized via a bypath of glycolysis from dihydroxyacetone phosphate and is believed to play a role in cell cycle regulation and stress adaptation. Also catalyzes the reduction of 3-methylbutanal to 3-methylbutanol. Acts as a suppressor of 3-methylbutanol-induced filamentation by modulating the levels of 3-methylbutanal, the signal to which cells respond by filamentation. Also involved in ergosterol metabolism. (S)-lactaldehyde + NADP(+) = H(+) + methylglyoxal + NADPH 3-methylbutanol + NADP(+) = 3-methylbutanal + H(+) + NADPH 3-methylbutanol + NAD(+) = 3-methylbutanal + H(+) + NADH Activated by glutathione. kcat is 31.3 min(-1) with 3-chloro-1-phenyl-1-propanol as substrate and 29.1 min(-1) for NADPH. Optimum pH is 7 for 2,5-hexanedione reduction, and 10 for the reverse reaction. Optimum temperature is 40 degrees Celsius for 3-chloro-1-phenyl-1-propanol reduction, and 54 degrees Celsius for 2,5-hexanedione reduction, and 30 degrees Celsius for the reverse reaction. Monomer. Repressed by SKO1. During osmotic stress, this repression is relieved. Induced by transcription factor YAP1 during oxidative stress, and induced by ionic and heat stress. Induced by isoamylalcohol. The N-terminus is blocked. Causes hyperfilamentation, probably due to the elevated levels of 3-methylbutanal in the mutant. Used as a biocatalyst, because the enzyme accepts a broad range of substrates including aliphatic and aromatic ketones, chloroketones, diketones as well as beta-ketoesters which are reduced with high stereoselectivity. Present with 5458 molecules/cell in log phase SD medium. 'De respuesta a estres' means stress response in Spanish. Belongs to the NAD(P)-dependent epimerase/dehydratase family. Dihydroflavonol-4-reductase subfamily.