Abstract
Resistance to stripe rust in wheat is a preferred method of disease prevention. Race-specific all-stage resistance usually provides complete protection; thus an understanding of the molecular control of race-specific resistance is important. To build on previous studies of race-specific resistance controlled by the Yr5 gene, this study reports the construction and use of a custom oligonucleotide microarray to perform a meta-analysis of the transcriptional response involved in race-specific resistance conferred by Yr1, Yr5, Yr7, Yr8, Yr9, Yr10, Yr15, and Yr17. By profiling the response of eight resistance genes in a common background, we identified 28 transcripts significantly involved in the resistance phenotype across all genotypes. The most significant of these were annotated as blue copper-binding protein, heat-stress transcription factor, pathogen-induced WIR1A protein, and ent-kaurene synthase transcripts. Unique transcripts significant in each genotype were also identified, which highlighted some transcriptional events specific to certain genotypes. The approach was effective in narrowing down the list of candidate genes in comparison to studying individual genotypes. Annotation revealed key gene expression events involved in race-specific resistance. The results confirm the activity of known R-gene-mediated pathway race-specific resistance, including an oxidative burst that likely contributes to a hypersensitive response, as well as pathogenesis-related protein expression and activity of the phenylpropanoid pathway. However, several identified transcripts remained unknown and may prove interesting candidates for further characterization.
