Effects of rutin on vegetative growth of mung bean (Vigna radiata) seedlings and its interaction with indoleacetic acid.

Rutin is one of the natural flavonoids in plants. Effects of rutin and indoleacetic acid (IAA) on vegetative growth of mung bean seedlings were studied and the contents of rutin and IAA in the hypocotyls of the seedlings were measured. Mung bean seedlings absorbed rutin through roots, grew more vigorously under light at lower rutin concentrations (20-60 microg/mL) with longer shoot axis (epicotyl+hypocotyl) and primary root and more lateral roots. The seedlings exhibited inhibition of elongation of the hypocotyls and radicles when grown in the dark at rutin concentrations of 20-100 microg/mL or under light at rutin concentrations of 80-100 microg/mL. Seedlings under light absorbed more rutin than those in the dark at rutin concentrations of 60-80 microg/mL and absorbed less rutin at concentrations lower than 40 microg/mL or near 100 microg/mL. IAA (>0.1 microg/mL) treatment promoted rutin accumulation and inhibited elongation of shoot axis and primary roots. The rutin content in hypocotyls reached the highest level when IAA (0.5 microg/mL) and rutin (40 microg/mL) were added to the medium. Rutin repressed endogenous IAA accumulation in hypocotyls of the etiolated seedlings and inhibited absorption of exogenous IAA from media to seedlings.