Influence of GA on Uptake and Accumulation of Naptalam by Bean Plants

Abstract

Bean plants (Phaseolus vulgaris L. var. Black Valentine) pretreated with gibberellic acid (hereinafter referred to as GA) absorb and accumulate considerably more N-1-naphthylphthalamic acid (naptalam) than untreated plants. All concentrations of GA from 2.9 × 10−6 to 8.6 × 10−4M were effective; peak influence occurred at 6 × 10−4M. Plants pretreated with this concentration took up 58% more naptalam than untreated plants. When the different parts of the plant were analyzed for naptalam separately, the leaf area (on a per g dry weight basis) was influenced most by GA pretreatment. The leaf area of bean plants pretreated with 2.9 × 10−4M contained 212% more naptalam than the leaf area of untreated plants. The leaf area also included all stem and petiole tissue above and including the first true leaves.