IAA-oxidase in Impatiens balsamina affected by GA₃ and tannic acid

Abstract

The activity of IAA-oxidase increased in the leaves of Impatiens balsamina plants receiving inductive photoperiodic cycles and in plants receiving treatments with gibberellic acid (GA₃) and/or tannic acid (TA), even under non-inductive photoperiods; the activity also increased in the stem receiving inductive photoperiodic cycles (8 h). Treatment with GA₃ and TA mimics the effect of SD cycles in the development of some isoenzymes of IAA-oxidase. Thus a new isoenzyme at R_f 0.48 developed in the leaves and one at R_f 0.82 developed in both the stem and the leaves of all plants receiving inductive treatments – photoperiodic or chemical – but not in water-treated controls under non-inductive photoperiods. Another isoenzyme at R_f 0.68 developed only in the stems.