Disclosed is a substantially purified or isolated nucleic acid or nucleic acid fragment encoding a MYB protein, or complementary or antisense to a sequence encoding a MYB protein, said nucleic acid or nucleic acid fragment including a nucleotide sequence as defined in the complete specification. Also disclosed is a method of modifying: flavonoid biosynthesis in a plant； protein binding, metal chelation, anti-oxidation, and/or UV-light absorption in a plant； pigment production in a plant； plant defence to a biotic stress； and forage quality of a plant by disrupting protein foam and/or conferring protection from rumen pasture bloat. The method includes introducing said nucleic acid into a plant.
