Peroxidase and polyphenol oxidase activity in malformed mango inflorescence caused by Fusarium moniliforme var. subglutinans.
Chattopadhyay N. C., Nandi B.
Author Affiliation: Burdwan University, Burdwan, West Bengal, India.
Biologia Plantarum 18 : 321-326
Abstract : Peroxidase and polyphenol oxidase activities in malformed inflorescences of the mango cvs. Himsagar and Bombay Green increased considerably following infection by F. moniliforme var. subglutinans. It is not known whether such increased activities were due to their synthesis by the pathogen or the host, or both, although it was found that the pathogen was incapable of producing the enzymes in vitro. The activities of both enzymes in infected tissues increased considerably during the experimental period. Polyphenol oxidase activity was inhibited by sodium diethyldithiocarbamate or phenylthiourea; the former acted as a chelating agent of enzyme Cu and the latter as a competitive inhibitor. Similarly, peroxidase activity was inhibited by cycloheximide, which acted as an inhibitor of enzyme protein synthesis. Himsagar showed greater enzyme activity than Bombay Green and may have higher resistance to the pathogen.