The effect of ethylene and ionizing radiation on Saintpaulia peroxidase activity

Ethylene gas and X rays, alone and in combination, were applied to petioles of Saintpaulia ionantha Wendl. to test their effect on peroxidase activity. Both agents increased peroxidase activity, although ethylene was the most effective. X ray treatment of petioles at five different peroxidase levels showed that as the initial activity of peroxidase increased the effect of a given dose of radiation decreased. Also, high doses, near the lethal limit for the species, were proportionately less effective in inducing peroxidase activity than were lower doses. Polyacrylamide disc electrophoresis showed no change in isozyme patterns with increases in peroxidase activity.