Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 2/12/2008
Publication Date: 11/19/2008
Citation: Dowd, P.F., Johnson, E.T., Pinkerton, T.S., Hughes, S.R. 2008. Genetically modified plants containing plant-derived genes for broad spectrum insect control to reduce mycotoxins. In: Wolf, T.V. and Koch, T.J.P., editors. Bioactive Proteins. Hauppauge, NY: Nova Science Publishers. p. 127-150.
Technical Abstract: Mycotoxins are acutely toxic or carcinogenic compounds produced primarily by Aspergillus and Fusarium molds that infect seeds of high oil content in the field, such as maize, cotton seed, peanuts, and tree nuts. Damage by insects facilitates entry of the molds, and maize hybrids that express Bacillus thuringiensis (Bt) crystal protein at sufficiently high levels to provide near immunity to pests (such as the European corn borer) can have greatly reduced levels of mycotoxins such as fumonisin in the presence of these pests. However, the number of ear-damaging insect pests requires many different Bts, and the recent reports of European corn borer populations in the field with high levels of resistance to Bt cryIAb, suggest nonBt strategies for broad spectrum insect control may be valuable in the future. Our approach toward solving the mycotoxin problem involves the investigation of plant-derived genes alone and in combination that have the potential to provide high levels of resistance to insects, including those that can be used as selectable markers. We have investigated directly active proteins, such as ribosome inactivating proteins and N-acetyl hexosamindases, and demonstrated significant affects against both beetles and caterpillars when expressed transgenically. Broad spectrum resistance to insects in several different orders has been noted for plants producing enhanced levels of peroxidases, including in the field. A model anti-cell-death protein enhanced insect resistance when expressed in transgenic plants. Robotics has been used to develop antiinsectan peptides with enhanced activity over original forms. We have recently begun to introduce combinations of some of these directly active genes that produce proteins in different functional classes, and have identified plants with resistance greatly enhanced over that seen with the individual genes.