Flavonoids affect how plants interact with (Brady)rhizobium and vesicular-arbuscular mycorrhizae (VAM) microsymbionts, microbial pathogens, insect predators, insect pollinators and herbivores. Legumes are a particularly rich source of flavonoid compounds, so the diversity of these agriculturally important molecules in agronomic lines and cultivars could be exploited for increased food production. Also, the widespread distribution of flavonoids in plants, especially in unselected native flora of developing countries, could be explored for their increased use in medicine and disease control.