[The effect of low temperature, nitrogen atmosphere and uncouplers on longitudinal distribution of radioactivity after acropetal and basipetal application of [2-(14)C] ABA in long root segments of Phaseolus coccineus L].

Acropetal movement of [2-(14)C] abscisic acid (ABA) in long root segments of P. coccineus is drastically reduced by destruction of the tissue, low temperature, anaerobic conditions and pretreatment with CCCP (carbonyl-cyanide-m-chloro-phenylhydrazone) at uncoupling concentrations. Basipetal transport is not affected by destruction of the tissue but markedly inhibited by the other treatments. Consequently polarity of ABA-transport disappears only after the roots have been killed. The importance of using long segments for hormone transport studies is discussed.