2011 Annual Report 1a.Objectives (from AD-416) Assess the role of the ethylene signaling pathway in Fusarium head blight (FHB) resistance mechanism of wheat. 1b.Approach (from AD-416) Full length cDNAs of genes encoding ethylene-inducible signalling components will be generated. DNA constructs designed to overexpress these cDNAs will be constructed and transformed into wheat. The resulting transgenic wheat plants will be tested for improved FHB resistance. 3.Progress Report Identification of wheat genes involved in resistance to Fusarium head blight (FHB) has been very difficult for two major reasons. First, wheat has at least six copies of most genes so conventional mutagenesis cannot reveal the affect of the loss of gene function, because there are always other functional copies present that mask the mutation. Second, it is very difficult to transform wheat so T-DNA mutations or T-DNAs expressing RNAi constructs are not feasible. Our approach utilizes virus-induced gene silencing (VIGS) to simultaneously down-regulate the expression of all copies of chosen genes. As virus infection of wheat is very rapid, the results of VIGS experiments can be observed within one month of inoculating the plant with the VIGS construct. In the past year several new genes making significant contributions to FHB resistance have been identified through VIGS testing. We are now in the process of confirming the degree to which the candidate genes were silenced in the VIGS studies. The ADODR monitoring of this project is accomplished through frequent face-to-face meetings with the collaborator, whose laboratory is located in the same building.