High Throughput Screening of Antifungal Toxins Targeted Against Plant Pathogenic Fungi

Twenty five percent of the world’s food crops are thought to be lost every year due to disease and spoilage caused by fungi. Management efforts that control fungal growth are being utilized, but can be ineffective due to a resistance to commercial fungicides. A potential answer to this problem lies in certain fungi, specifically yeast, which produce a variety of secreted protein toxins (“killer toxins”), which are a fungicidal to many different plant pathogens. Using high throughput screening methods, we have screened forty-seven known “killer” yeasts for activity against the plant pathogen Botrytis cinerea and found nineteen that inhibited growth. These candidates were then tested individually to confirm the production of a proteinaceous killer toxin. In addition to Botrytis cinerea, this method will be used to screen hundreds of yeast strains as biological control agents against a variety of pathogenic fungi. This project is the first critical step in developing the fungicidal properties of killer toxin producing yeast as a control strategy to mitigate crop loss