Barley MLA3 recognizes the host-specificity effector Pwl2 from Magnaporthe oryzae

Plant Cell. 2024 Jan 30;36(2):447-470. doi: 10.1093/plcell/koad266.


Plant nucleotide-binding leucine-rich repeat (NLRs) immune receptors directly or indirectly recognize pathogen-secreted effector molecules to initiate plant defense. Recognition of multiple pathogens by a single NLR is rare and usually occurs via monitoring for changes to host proteins; few characterized NLRs have been shown to recognize multiple effectors. The barley (Hordeum vulgare) NLR gene Mildew locus a (Mla) has undergone functional diversification, and the proteins encoded by different Mla alleles recognize host-adapted isolates of barley powdery mildew (Blumeria graminis f. sp. hordei [Bgh]). Here, we show that Mla3 also confers resistance to the rice blast fungus Magnaporthe oryzae in a dosage-dependent manner. Using a forward genetic screen, we discovered that the recognized effector from M. oryzae is Pathogenicity toward Weeping Lovegrass 2 (Pwl2), a host range determinant factor that prevents M. oryzae from infecting weeping lovegrass (Eragrostis curvula). Mla3 has therefore convergently evolved the capacity to recognize effectors from diverse pathogens.

MeSH terms

  • Ascomycota*
  • Eragrostis* / metabolism
  • Hordeum* / genetics
  • Host Specificity
  • Magnaporthe*
  • Plant Diseases / microbiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plants / metabolism
  • Virulence / genetics


  • Plant Proteins

Supplementary concepts

  • Pyricularia oryzae