Abstract
To determine the fate of gibberellic acid (GA3), solutions were incubated for 24 hr. with or without barley endosperm and were subsequently applied to dwarf maize seedlings. Hormone activity appeared to increase as a result of incubation with endosperm. This apparent increase in GA3 concentration was probably due to a synergistic interaction between GA3 and endosperm constituents, particularly carbohydrate, released during the incubation period. Relatively little hormone is probably inactivated during the initiation of endosperm mobilization.