Submitted to: Plant Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2009
Publication Date: March 6, 2009
Citation: Scofield, S.R. 2009. Functional dissection of wheat disease resistance pathways. Plant Genome Conference Proceedings. Interpretive Summary: This presentation discusses the difficulties in identifying the functions of genes in wheat. To overcome these issues we have developed a virus-induced gene silencing system for wheat. We have utilized this system to find genes that have essential functions in 3 different disease resistance pathways in wheat. The presentation will describe the work probing these resistance pathways and use it to illustrate the strengths and limitations of the technique.
Technical Abstract: Wheat is an essential component of human food supply. We are working to identify genes that mediate resistance to the most significant pathogens of wheat, so that ultimately, we can engineer improved disease resistance. We are employing virus-induced gene silencing (VIGS) to test if candidate genes have essential functions in disease resistance pathways. VIGS is particularly useful for functional genomics in wheat for two reasons: 1) most cultivated wheat is hexaploid, which greatly complicates gene identification through mutant analysis and 2) wheat is very recalcitrant to transformation, which makes gene identification strategies based on creating transgenic plants very difficult. We have utilized VIGS to study three different modes of disease resistance: gene-for-gene based resistance to leaf rust, non-host resistance to Cochliobolus carbonum race 1 and resistance to Fusarium head blight conditioned by quantitative trait loci (QTLs). While VIGS is proving to be a very useful tool for identification of wheat gene function, we are frequently encountering obstacles due to the lack of wheat genomic sequence and its hexaploidy. This presentation will discuss the strengths and weaknesses of this approach to functional genomics in wheat.