NEW PROTEIN, GENE CODING FOR THE PROTEIN AND THEIR USE

摘要

PROBLEM TO BE SOLVED: To screen and identify a new antifungal protein which can inhibit, at a relatively low concentration, the growth of plant pathogenic fungi such as Pyricularia oryzae and Rhizoctonia solani both of which cause two major diseases for Oryza sativa, and to clone a gene coding for the protein. SOLUTION: This protein can be obtained from a fraction which precipitates from an aqueous extract from Tricholoma matsutake by ammonium sulfate precipitation, has an antifungal activity against at least Pyricularia oryzae or Rhizoctonia solani, a molecular weight of about 210 kD as determined by gel filtration, gives components having molecular weights of about 50 kD and about 15 kD as determined by SDS-PAGE. The activity is not lost by the heat treatment in a neutral solution at 60 deg.C for 10 min, but lost by the heat treatment in a neutral solution at 80 deg.C for 10 min.