Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 15, 2002
Publication Date: September 1, 2002
Citation: Chlan, C.A., Cary, J.W., Rajasekaran, K., Cleveland, T.E. 2002. Construction of expression cassettes to confer resistance to Aspergillus flavus in cotton. Proceedings of the 14th Aflatoxin Elimination Workshops, October 23-26, 2001, Phoenix, Arizona. p. 143. Technical Abstract: We have been working to develop cotton that is resistant to the fungal pathogen Aspergillus flavus using a genetic engineering approach. Success of this project depends upon the identification of appropriate regulatory elements, as well as structural genes that can be linked to confer a new pathogen resistant phenotype to cotton. Based on our previous studies, we have identified several regulatory elements (promoters) that will be useful tools in this approach. These promoter components include native cotton promoter elements derived from a cottonseed storage protein vicilin promoter and the cotton chitinase gene promoter, as well as heterologous promoter elements that are constitutively expressed, such as the ubiquitin and Cauliflower Mosaic Virus promoters. A variety of candidate structural genes whose products may confer resistance to A. flavus have been identified. These include a haloperoxidase gene, a lytic peptide coding sequence, the corn trypsin inhibitor gene, and a cotton chitinase gene. Previously, we presented detailed studies characterizing natural cotton defense gene, a neutral cotton chitinase. We also continued our studies in transgenic plants to determine expression levels and efficacy of a variety of promoter/structural gene combinations against different pathogens. Currently, we are focusing on generating different promoter/structural gene combinations in the final phase of developing cotton with resistance to A. flavus.