Evidence for close association of peroxidase, polyphenol oxidase, and IAA oxidase isozymes of peanut suspension culture medium

Abstract

Peroxidase, polyphenol oxidase, and indole-3-acetic acid (IAA) oxidase were detected in a 7-day-old medium of a peanut cotyledon cell suspension culture. Preliminary separation of the isozymes of these three enzymes was achieved by acetone fractionation and acetic acid extraction. By means of zymograms on polyacrylamide gels, five anionic and two cationic peroxidase isozymes were identified. Staining of the gels for polyphenol oxidase and IAA oxidase revealed an Rf pattern for a number of isozymes that was identical with that found for peroxidase. These isozymes were separated using ion-exchange chromatography. Again the elution pattern for the isozymes of the three enzymes was so similar that it can be regarded as an enzyme possessing all the three types of activity.