Patrick Schweizer
Race-nonspecific resistance of barley to powdery mildew: one trait – many genes
Leibniz Institute of Plant Genetics and Crop Plant Research, 06466 Gatersleben, Germany
Race-nonspecific (basal) pathogen resistance is of high importance to plant breeders due to its durability. However, it is usually controlled by multiple quantitative trait loci. Knowing about the underlying genes would allow more targeted exploitation in practice by allele introgressions. In order to identify genes that mediate race-nonspecific resistance of barley to the powdery mildew fungus Blumeria graminis f.sp. hordei we combined a functional-genomics approach based on genomewide transcript profiling and transient-induced gene silencing (TIGS, 1400 genes) with association-genetic (re-sequencing) and meta-QTL mapping approaches. This guided us to a shortlist of 50 candidates with converging evidence for an important role in race-nonspecific resistance of barley. Candidates of special interest encode proteins involved in cell-death regulation such as HvLsd1a and in cell-wall re-shaping such as Germin-like proteins or cellulose-synthase like proteins. In general, we believe that the integration of functional-genomic with genetic approaches allows for a targetted and accelerated discovery of genes underlying complex, quantitative traits in barley and in other crop plants, with the prospect to utilize and combine favourable alleles in a knowledge-driven approach.