The liberation of inhibitors of indoleacetic acid oxidase activity out of Coleus internodes treated with potassium hydroxide or sulphuric acid

The presence of indoleacetic acid as the natural growth substance in Coleus has been demonstrated by Scott & Jacobs (1964), whereas indoleacetic acid oxidase activity of preparations of Coleus has been reported by Kaminski (1966). In earlier experiments (Soekarjo 1965), it was shown that treatment of cuttings of Coleus with potassium hydroxide or sulphuric acid results in a stimulation of the formation of adventitious roots. It seemed possible that the mechanism by which these treatments caused the enhanced formation of adventitious roots depended upon interference with the concentration of endogenous auxin. Therefore, we investigated the effect of the diffusate of treated internodes on the activity of indoleacetic acid oxidase.