Multiple forms of polygalacturonase in two strains of Rhizoctonia solani.

An unspecialized strain of Rhizoctonia solani (FC895) produced in vitro seven isoenzymes (four major and three minor peaks) which were separated by isoelectric focusing over a narrow pH range. The same isoenzyme pattern was detected when hypocotyls of cauliflower seedlings inoculated with the fungus were used as the enzyme source. A specialized strain (FC1241) produced two isoenzymes (one major and one minor peak). The four major isoenzymes of FC895 and the major isoenzyme of FC1241 had the same pH optimum and mode of action on sodium polypectate.