[Effect of light on transport of 2-[(14)C]abscisic acid through root segments of runner beans].

Light promotes the acropetal movement of 2-[(14)C]ABA through root segments of Phaseolus coccineus L. The promotion occurs only when the segments are irradited during the transport period. Red light and blue light are as effective as white light. There is no significant promotion when the segments are irradiated with green light or when they are kept in darkness during the transport period after preceding light treatment. Light has no effect on basipetal ABA-transport.