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 Rf 0.48 developed in the leaves and one at Rf 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 Rf 0.68 developed only in the stems.