Bean seed colour: Summary of Evidence

Cellular: Seed coat derived from mitotic cells, Consists of five cell layers, Cell layers die (apoptosis) when seed matures, Pigmentation intensifies as cell layers die. Genetic: Dominant ‘Ground factor’ P allele is required for pigmentation, Several pigment biosynthesis genes, Several modifying/ intensifying genes, Patterning On/off switch genes. Biochemical: Colour genes encode enzymes for biosynthesis of flavonoids, Pattern gene(s) are probably transcription factors