title: Discovery of genes affecting resistance of barley  to adapted and non-adapted powdery mildew  fungi.
abstract: BACKGROUND
  Non-host resistance, NHR, to non-adapted pathogens and quantitative host resistance, QR, confer durable protection to plants and are important for securing yield in a longer perspective. However, a more targeted exploitation of the trait usually possessing a complex mode of inheritance by many quantitative trait loci, QTLs, will require a better understanding of the most important genes and alleles.
  
  
  RESULTS
  Here we present results from a transient-induced gene silencing, TIGS, approach of candidate genes for NHR and QR in barley against the powdery mildew fungus Blumeria graminis. Genes were selected based on transcript regulation, multigene-family membership or genetic map position. Out of 1,144 tested RNAi-target genes, 96 significantly affected resistance to the non-adapted wheat- or the compatible barley powdery mildew fungus, with an overlap of four genes. TIGS results for QR were combined with transcript regulation data, allele-trait associations, QTL co-localization and copy number variation resulting in a meta-dataset of 51 strong candidate genes with convergent evidence for a role in QR.
  
  
  CONCLUSIONS
  This study represents an initial, functional inventory of approximately 3% of the barley transcriptome for a role in NHR or QR against the powdery mildew pathogen. The discovered candidate genes support the idea that QR in this Triticeae host is primarily based on pathogen-associated molecular pattern-triggered immunity, which is compromised by effector molecules produced by the compatible pathogen. The overlap of four genes with significant TIGS effects both in the NHR and QR screens also indicates shared components for both forms of durable pathogen resistance.
authors.forename: Dimitar
authors.initials: D
authors.lastname: Douchkov
authors.forename: Stefanie
authors.initials: S
authors.lastname: Lück
authors.forename: Annika
authors.initials: A
authors.lastname: Johrde
authors.forename: Daniela
authors.initials: D
authors.lastname: Nowara
authors.forename: Axel
authors.initials: A
authors.lastname: Himmelbach
authors.forename: Jeyaraman
authors.initials: J
authors.lastname: Rajaraman
authors.forename: Nils
authors.initials: N
authors.lastname: Stein
authors.forename: Rajiv
authors.initials: R
authors.lastname: Sharma
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kilian
authors.forename: Patrick
authors.initials: P
authors.lastname: Schweizer
mesh_terms: D000220:Adaptation, Biological; D001203:Ascomycota / Q000502:physiology*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D040641:Quantitative Trait Loci