Role of Pectic Enzymes in the Verticillium Wilt Disease of Cotton

Abstract

THE mechanism by which Verticillium dahliae produces symptoms of wilt disease in young cotton plants has been investigated by assaying solutions from cultures of the pathogen on liquid media for the following activities: (a) protopectinase, from the time taken to macerate standard slices of potato tuber tissue; (b) pectinesterase, from the rate of liberation of acidic groups from a solution of a high methoxyl pectin; (c) toxicity, from the rate of killing of parenchyma cells of potato tuber slices; (d) wilting, from the time taken to cause irreversible wilting of cotton shoots; (e) vascular browning, from the degree of discoloration of the vascular elements of cotton shoots.