ARS | Publication request: Virus-Induced Gene Silencing in Hexaploid Wheat

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2006
Publication Date: January 13, 2007
Citation: Scofield, S.R., Cakir, C., Brandt, A.S., Kong, L., Anderson, J.M. 2007. Virus-Induced Gene Silencing in Hexaploid Wheat. Plant and Animal Genome VX Conference Abstracts. p. 794.

Technical Abstract: Functional genomics analysis in hexaploid wheat is greatly impeded by the genetic redundancy of polyploidy and the difficulties in generating large numbers of transgenic plants required in insertional mutagenesis strategies. Virus-induced gene silencing (VIGS), however, is a strategy for creating gene knockouts that overcomes both of these impediments: 1) Being a homology-dependent silencing process, it can suppress expression any redundant gene copies that share at least ~85% sequence homology. 2) VIGS is initiated by viral infection, which is a rapid and easy process, unlike regenerating transformed wheat plants. For these reasons we have worked to develop a VIGS system for creating gene knockout phenotypes in hexaploid wheat. Our VIGS system is based on Barley stripe mosaic virus (BSMV). Data will be presented describing the general properties of this silencing system. We are particularly interested in functionally identifying genes that are essential for disease resistance responses in wheat. To this end, we have developed protocols for silencing candidate genes so that we can test if their expression is essential for resistance. We have successfully employed this system to analyze genes required in resistance pathways to leaf rust and several other foliar pathogens of wheat. Very recently, we have developed protocols for silencing genes in the spikes and heads of wheat and are now using BSMV-VIGS to identify genes essential for resistance to Fusarium head blight.