Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/10/2006
Publication Date: 4/5/2006
Citation: Dowd, P.F., Holmes, R.A., Pinkerton, T.S., Johnson, E.T., Lagrimini, L.M., Boston, R.S. 2006. Relative activity of a tobacco hybrid expressing high levels of a tobacco anionic peroxidase and maize ribosome-inactivating protein against Helicoverpa zea and Lasioderma serricorne. Journal of Agricultural and Food Chemistry. 54(7):2629-2634. Interpretive Summary: Insect damage to crops causes considerable economic losses as well as losses due to contamination with associated mold toxins. Two insect resistance genes were combined by crossing individual tobacco plants expressing the individual genes at high levels as part of a model system. The crossed plants were significantly more resistant to feeding by representative caterpillar and beetle species compared to wild-type plants, and there were no obvious incompatibilities between the two proteins expressed by the genes. These genes appear to be useful candidates for combination into stable, multigenic insect resistance plant transformants, which should result in economic benefits for producers and healthier foods for consumers.
Technical Abstract: Tobacco (Nicotiana tabacum) plants grown from seed obtained by crossing a tobacco line that expressed maize ribosome-inactivating protein (RIP) with a line that overexpressed tobacco anionic peroxidase were tested for their effects on corn earworm Helicoverpa zea and cigarette beetle Lasioderma serricorne larvae compared to the wild-type plant cross. Significant feeding reductions were noted for transgenic compared to wild-type plants for both H. zea and L. serricorne. Significant increases in mortality were also noted for those insects fed on the transgenic cross compared to wild-type plants in some cases. Levels of both peroxidase and maize RIP were significantly higher in transgenic compared to wild-type plants (wild-type tobacco plants did not produce any maize RIP). The degree of feeding was significantly negatively correlated with the level of RIP or peroxidase individually.