Non-host resistance genes in Brachypodium distachyon against the rust pathogen Puccinia graminis
F. LI (1), V. Omidvar (1), R. Milne (2), S. Kianian (3), J. Vogel (4), M. Ayliffe (5), M. Moscou (6), P. Dodds (2), E. Lagudah (2), M. Figueroa (1) (1) University of Minnesota, U.S.A.; (2) CSIRO Agriculture, Australia; (3) USDA-ARS Cereal Disease Laboratory, U.S.A.; (4) Joint Genome Institute, U.S.A.; (5) CSIRO Agriculture, U.S.A.; (6) The Sainsbury Laboratory, United Kingdom

Non-host resistance offers the possibility to provide durable resistance against a broad-spectrum of pathogens. Rust fungi cause devastating disease in cereals, and there is an ongoing need for new resources to improve rust resistance. Therefore we have established the grass Brachypodium distachyon as a prime system to study the basis of non-host resistance against multiple cereal rust species, including Puccinia graminis f.sp. tritici (Pgt). Pgt is the causal agent of stem rust and poses a serious threat to the global production of wheat and barley. Because of the phylogenetic relatedness of the B. distachyon to wheat and barley, this species has potential applications to translational research and food security. Taking a functional genomics approach, we initially characterized transcriptional changes observed after challenging B. distachyon with stem rust isolates by RNAseq analysis. This identified a list of candidate genes that may govern responses associated with plant-pathogen incompatibility. We are now using a collection of T-DNA insertion lines in B. distachyon to assess the role of these candidate genes in controlling non-host resistance against Pgt. Our disease screening platform involves genotyping T-DNA mutant lines of interest to confirm the postulated mutations, determining their rust infection phenotypes and selfing to produce homozygous lines. Preliminary data have identified two genes that may contribute to disease outcomes; a WRKY transcription factor and the ortholog of the wheat gene Lr67, which confers multi-pathogen resistance in wheat. Current work on the functional and molecular characterization of these genes will be presented.

Abstract Number: P17-557
Session Type: Poster