The AvrPm3-Pm3 effector-NLR interactions control both race-specific resistance and host-specificity of cereal mildews on wheat

Nat Commun. 2019 May 23;10(1):2292. doi: 10.1038/s41467-019-10274-1.

Abstract

The wheat Pm3 resistance gene against the powdery mildew pathogen occurs as an allelic series encoding functionally different immune receptors which induce resistance upon recognition of isolate-specific avirulence (AVR) effectors from the pathogen. Here, we describe the identification of five effector proteins from the mildew pathogens of wheat, rye, and the wild grass Dactylis glomerata, specifically recognized by the PM3B, PM3C and PM3D receptors. Together with the earlier identified AVRPM3A2/F2, the recognized AVRs of PM3B/C, (AVRPM3B2/C2), and PM3D (AVRPM3D3) belong to a large group of proteins with low sequence homology but predicted structural similarities. AvrPm3b2/c2 and AvrPm3d3 are conserved in all tested isolates of wheat and rye mildew, and non-host infection assays demonstrate that Pm3b, Pm3c, and Pm3d are also restricting the growth of rye mildew on wheat. Furthermore, divergent AVR homologues from non-adapted rye and Dactylis mildews are recognized by PM3B, PM3C, or PM3D, demonstrating their involvement in host specificity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ascomycota / isolation & purification
  • Ascomycota / pathogenicity
  • Ascomycota / physiology*
  • Dactylis / microbiology
  • Disease Resistance / immunology
  • Edible Grain / immunology
  • Edible Grain / microbiology
  • Fungal Proteins / genetics
  • Fungal Proteins / immunology*
  • Fungal Proteins / metabolism
  • Genome, Fungal
  • Genome-Wide Association Study
  • Host Specificity*
  • NLR Proteins / immunology
  • NLR Proteins / metabolism
  • Nicotiana / genetics
  • Nicotiana / microbiology
  • Plant Diseases / immunology*
  • Plant Diseases / microbiology
  • Plant Proteins / immunology*
  • Plant Proteins / metabolism
  • Plants, Genetically Modified
  • Secale / microbiology
  • Triticum / immunology*
  • Triticum / microbiology

Substances

  • Fungal Proteins
  • NLR Proteins
  • Plant Proteins
  • Pm3b protein, Triticum aestivum