The invention relates generally to isolated leucoanthocyanidin reductase LAR polypeptides of the Reductase-Epimerase-Dehydrogenase (RED) protein family, and nucleic acid molecules encoding same and their use in regulating the biosynthesis and accumulation of proanthocyanidins in plants. The invention is further directed to isolated nucleic acid molecules of plants, which encode leucoanthocyanidin reductases of the RED protein family. The isolated polypeptides and nucleic acid molecules of the present invention are useful for modifying the pasture quality of legumes, and, in particular, for producing bloat-safe forage crops, or crops having enhanced nutritional value, enhanced disease resistance or pest resistance, or enhanced malting qualities.