The isolation and partial characterization of monilicolin A, a polypeptide with phaseollin-inducing activity from Monilinia Fructicola

Abstract

The isolation and partial characterization of a polypeptide (mol.wt. ca 8,000) designated as monilicolin A is reported from mycelium of Monilinia fructicola. Monilicolin A is a sulphur-containing, highly water soluble peptide with ca 65 amino acid residues. No evidence for the presence of non amino acid groups was obtained. Monilicolin A is active as a phytoalexin-inducing agent at very low concentrations (ED50 = 8 × 10-9 M). Its action appears to be specific for phaseollin-induction in as far as it has been assayed at present. It is neither phytotoxic nor fungitoxic. The use of monilicolin A in studies on the induction of phaseollin biosynthesis is briefly discussed. © 1968.