Expression of Plant Genes in Neurospora crassa

Plants represent a largely untapped reservoir of therapeutic and other agents. Of the 250,000 to 300,000 plant species, only 5000 have been examined for medically useful compounds. Agents discovered include cardioactive steroids, vasoactive compounds, antineoplastic agents, e.g., taxol, insecticides (pyrethrins), ribosome inactivating proteins (e.g., ricin), abortifacient proteins (Karasuring) and antifungal proteins (chitinases, glucanases and permatins). However, many species producing useful pharmaceuticals are not crop plants and are not capable of being grown in large scale. This necessitates the use of heterologous systems in order to obtain large quantities of the desired compound or protein. We propose in this Phase I application to test the idea that the simple eukaryotic fungus, Neurospora crassa, can be used for the expression and production of plant proteins of high value using conventional submerged fermentation. In this proposal, we will test the feasibility that chimeric DNA constructs containing the gene for an inducible, secreted N. crassa protein fused with Zsa mays gene coding for an antifungal protein, zeamatin, can be used to transform N. crassa and that transformants will express and secrete zeamatin when induced.