Search for: All records

Stem rust is an important disease of wheat that can be controlled using resistance genes. The geneSuSr-D1identified in cultivar ‘Canthatch’ suppresses stem rust resistance.SuSr-D1mutants are resistant to several races of stem rust that are virulent on wild-type plants. Here we identifySuSr-D1by sequencing flow-sorted chromosomes, mutagenesis, and map-based cloning. The gene encodes Med15, a subunit of the Mediator Complex, a conserved protein complex in eukaryotes that regulates expression of protein-coding genes. Nonsense mutations in Med15b.D result in expression of stem rust resistance. Time-course RNAseq analysis show a significant reduction or complete loss of differential gene expression at 24 h post inoculation inmed15b.Dmutants, suggesting that transcriptional reprogramming at this time point is not required for immunity to stem rust. Suppression is a common phenomenon and this study provides novel insight into suppression of rust resistance in wheat.