Not “Ten Years After“ but “Twenty Years After“: Cloning of the barley Ror1 gene
R. PANSTRUGA (1), J. Acevedo (1), N. Ahmadinejad (2), K. Drwiega (1), M. Kwaaitaal (1), M. Mascher (3), K. Baumgarten (1), X. Dong (4), G. James (4), K. Schneeberger (4), N. Stein (3), P. Schulze-Lefert (4) (1) RWTH Aachen University, Germany; (2) University of Bonn, Germany; (3) IPK Gatersleben, Germany; (4) MPIPZ Köln, Germany

In barley, recessively inherited loss-of-function alleles of the Mildew resistance locus o (Mlo) gene confer broad-spectrum resistance against the powdery mildew pathogen Blumeria graminis f.sp. hordei. Immunity of mlo mutants is characterized by an early termination of fungal pathogenesis, prior to host cell entry. A genetic screen conducted in the mid 1990s identified two genes, designated Required for mlo-specified resistance 1 and 2 (Ror1 and Ror2), that are required for full mlo-based powdery mildew resistance. While Ror2 was cloned and found to encode a SNARE protein involved in vesicle fusion processes at the plasma membrane, the identity of Ror1 remained elusive. Here we report the cloning of Ror1, which is situated in a genetically unfavorable pericentromeric region of barley chromosome 1H that lacks synteny to other grass species. By the combination of classical mapping, YAC-based chromosome walking and whole transcriptome shotgun sequencing (RNAseq) of mutant alleles the gene was ultimately identified and found to encode an actin binding protein. Since genetic data suggest that Ror1 and Ror2 act in two separate genetic pathways, Ror1 may define a separate route required for antifungal broad-spectrum immunity in barley.

Abstract Number: P15-430
Session Type: Poster