Submitted to: Mycopathologia
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/8/2001
Publication Date: 10/15/2003
Citation: BRANDHORST, T., DOWD, P.F., KENEALY, W.R. THE EFFECT OF FUNGAL RIBOSOME INACTIVATING PROTEINS UPON FEEDING CHOICE IN C. FREEMANI, AND INDICATIONS OF A MUTUALISTIC RELATIONSHIP WITH A. RESTRICTUS. ENVIRONMENTAL MYCOLOGY. MYCOPATHOLOGIA. 2000. v. 152. p. 155-158. Interpretive Summary: Insects cause hundreds of millions of dollars in crop losses each year. They also can play a role in increasing the levels of mold toxins in corn and other crops, which additionally increases crop losses by hundreds of millions of dollars. New strategies for insect control may help reduce these losses. A gene coding for a protein produced by one species of fungus was transferred to another fungus species used as a model system that did not produce this protein. The transformed fungus had increased resistance to feeding by a beetle pest that damages corn and spreads molds that produced toxins in corn, compared to corresponding untransformed fungal strains. This protein may have value in controlling insect pests when expressed in relevant plant tissues, but further testing in plant systems and for potential allergenicity is necessary.
Technical Abstract: Carpophilus freemani beetles feeding on the fungus Aspergillus nidulans was substantially inhibited when A. nidulans was transformed and induced to secrete the ribosome inactivating protein, restrictocin. No inhibition was observed when the transformed fungi produced an inactive form of restrictocin with a single amino-acid substitution in the active site. Feeding inhibition of C. freemani by restrictocin requires that the ribonuclease be active and is not due to other characteristics of the protein.