INDOLE ACETIC ACID OXIDASE AND PEROXIDASE ACTIVITIES IN NORMAL AND CROWN GALL TISSUE CULTURES OF PARTHENOCISSUS TRICUSPIDATA

Lipetz , Jacques , and Arthur W. Galston . (Yale U., New Haven.) Indole acetic acid oxidase and peroxidase activities in normal and crown gall tissue cultures of Parthenocissus tricuspidata. Amer. Jour. Bot. 46(3) : 193-196. Illus. 1959.—Normal and crown gall cells of P. tricuspidata grown in pure culture were examined for IAA oxidase and peroxidase activities. No IAA oxidase activity could be demonstrated in dialyzed or undialyzed homogenates of either tissue; however, crown gall tissue, but not normal tissue, was found to produce an extracellular IAA oxidase which required Mn⁺⁺ and DCP as co-factors. Normal tissue, but not crown gall tissue was found to contain high levels of substances which spared IAA from destruction by a pea IAA oxidase preparation. Peroxidase activity was found to be higher in normal than in crown gall homogenates, but crown gall tissue released considerably more peroxidase into the external medium. The differences in the auxin requirements and growth rate between normal and crown gall cells appear not to be easily explicable in terms of differential auxin destruction.