Submitted to: Phytopathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/15/2001
Publication Date: N/A
Citation: Interpretive Summary: A significant portion of harvested produce is lost to decay organisms before it reaches the consumer. Limiting losses relies principally on storage monitoring and use of fungicides. Additional methods are needed which provide an effective control at minimal cost. One method involves the use of naturally occurring microbes which are found on the surface of fruits and vegetables. While these microbes are not very effective on their own they can be enhanced through genetic engineering to become very effective. Enhancement was demonstrated by adding a gene for a small protein that is found in nature. When the yeast Saccharomyces has the extra gene it can defend tomato fruits from rotting caused by the fungus Colletotrichum. This method may prove to be a widely used alternative to use of chemical fungicides, benefiting producers through reduced postharvest losses and benefiting consumers through reduced fungicide exposure and longer produce shelf life.
Technical Abstract: A cecropin B-based peptide inhibited germination of C. coccodes at 50 micromolar. The DNA sequence encoding the peptide was cloned in pRS413, using the Saccharomyces invertase leader sequence for secretion of the peptide, and expressed in yeast. Supernatants from liquid media in which the transformants grew inhibited the growth of germinated C. coccodes spores, and inhibited decay development caused by C. coccodes in tomato fruits. Expression of the antifungal peptide in yeast therefore represents a new approach for the biological control of postharvest diseases.