Arms race co-evolution of Magnaporthe oryzae AVR-Pik and rice Pik genes driven by their physical interactions

Plant J. 2012 Dec;72(6):894-907. doi: 10.1111/j.1365-313X.2012.05110.x. Epub 2012 Oct 19.


Attack and counter-attack impose strong reciprocal selection on pathogens and hosts, leading to development of arms race evolutionary dynamics. Here we show that Magnaporthe oryzae avirulence gene AVR-Pik and the cognate rice resistance (R) gene Pik are highly variable, with multiple alleles in which DNA replacements cause amino acid changes. There is tight recognition specificity of the AVR-Pik alleles by the various Pik alleles. We found that AVR-Pik physically binds the N-terminal coiled-coil domain of Pik in a yeast two-hybrid assay as well as in an in planta co-immunoprecipitation assay. This binding specificity correlates with the recognition specificity between AVR and R genes. We propose that AVR-Pik and Pik are locked into arms race co-evolution driven by their direct physical interactions.

Keywords: Magnaporthe oryzae; Oryza sativa; arms race; avirulence gene; coevolution; population genetics; resistance gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Disease Resistance
  • Evolution, Molecular
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Fungal
  • Gene Expression Regulation, Plant
  • Host-Pathogen Interactions*
  • Magnaporthe / genetics*
  • Magnaporthe / pathogenicity
  • Models, Biological
  • Mutation
  • Oryza / genetics*
  • Oryza / microbiology
  • Plant Diseases / microbiology*
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Protein Structure, Tertiary
  • Sequence Analysis, DNA
  • Two-Hybrid System Techniques
  • Virulence


  • Fungal Proteins
  • Plant Proteins