Peroxidase and Polyphenol Oxidase Associated with, Induced Resistance of Mung Bean to Rhizoctonia solani Kuhn

Abstract Peroxidase and polyphenol oxidase activities and peroxidase isozyme patterns were determined at different stages of hypocotyls of mung bean infected with Rhizoctonia solani. The effect of ethephon (2‐chloroethyl phosphonic acid) has been studied. Peroxidase activity increased at 24 h after inoculation as compared with controls followed by a decline later. It increased at 120 h. Polyphenol oxidase activities increased after inoculation. Ethephon treatment increased the resistance to Rhizoctonia solani and enhanced peroxidase and polyphenol oxidase activities. Peroxidase isozyme pattern was found to change as a result of inoculation and ethephon treatment. The results indicated that ethephon‐induced resistance was related to peroxidase and polyphenol oxidase activities.