Effector specialization in a lineage of the Irish potato famine pathogen

Science. 2014 Jan 31;343(6170):552-5. doi: 10.1126/science.1246300.


Accelerated gene evolution is a hallmark of pathogen adaptation following a host jump. Here, we describe the biochemical basis of adaptation and specialization of a plant pathogen effector after its colonization of a new host. Orthologous protease inhibitor effectors from the Irish potato famine pathogen, Phytophthora infestans, and its sister species, Phytophthora mirabilis, which is responsible for infection of Mirabilis jalapa, are adapted to protease targets unique to their respective host plants. Amino acid polymorphisms in both the inhibitors and their target proteases underpin this biochemical specialization. Our results link effector specialization to diversification and speciation of this plant pathogen.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence / genetics
  • Amino Acid Substitution / genetics
  • Evolution, Molecular
  • Mirabilis / enzymology*
  • Mirabilis / microbiology*
  • Phylogeny
  • Phytophthora infestans / genetics
  • Phytophthora infestans / pathogenicity*
  • Plant Diseases / microbiology*
  • Plant Proteins / classification
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Polymorphism, Genetic
  • Proteinase Inhibitory Proteins, Secretory / classification
  • Proteinase Inhibitory Proteins, Secretory / genetics
  • Proteinase Inhibitory Proteins, Secretory / metabolism*
  • Solanum tuberosum / enzymology*
  • Solanum tuberosum / microbiology*
  • Species Specificity


  • Plant Proteins
  • Proteinase Inhibitory Proteins, Secretory