CHARACTERIZATION OF AN EXTRACELLULAR BETA-1,3-GLUCANASE OF CLAVICEPS-PURPUREA

The phytopathogenic fungus Claviceps purpurea produces an extracellular β-1,3-glucanase in axenic culture. The enzyme was purified and characterized. It is a glycoprotein with a pH optimum of 4·5, a molecular weight of about 90 kDa, and an isoelectric point of 9·0. The latter two properties are unusual for a fungal β-1,3-glucanase. Analysis of substrate specificity confirmed that the enzyme is a specific endo-β-1,3-glucanase. A comparable enzyme was also detected in honeydew of infected plants. A possible role for this enzyme in host-parasite interaction (degradation of callose protecting the host's vascular tissue) is discussed. © 1992.