Abscisic acid and apical dominance in Phaseolus coccineus L.

摘要: Abscisic acid (ABA) in lanolin, applied to the internode of decapitated runner bean plants enhances outgrowth lateral buds. The optimum concentration paste is 10(-5) M. effect ABA counteracted by indoleacetic (IAA) but not gibberellic (GA3). There no when apical bud or buds intact plants. However, 13.2 ng given stimulate their growth, whereas higher concentrations are inhibitory. Consequently, growth directly, only dominance already weakened. 2(nd) was affected ABA. Radioactivity from [2-(14)C] ABA, nonelongating stumps moves buds, [1-(14)C]IAA-and [(3)H]GA1-translocation much weaker. transport inhibited if IAA [(3)H]GA1 simultaneously. In elongating internodes [(14)C]ABA almost completely immobile. [(14)C]IAA-and amount radioactivity labelled translocated highest during early stages outgrowth.