Co-incidence of Damage and Microbial Patterns Controls Localized Immune Responses in Roots

Cell. 2020 Feb 6;180(3):440-453.e18. doi: 10.1016/j.cell.2020.01.013.


Recognition of microbe-associated molecular patterns (MAMPs) is crucial for the plant's immune response. How this sophisticated perception system can be usefully deployed in roots, continuously exposed to microbes, remains a mystery. By analyzing MAMP receptor expression and response at cellular resolution in Arabidopsis, we observed that differentiated outer cell layers show low expression of pattern-recognition receptors (PRRs) and lack MAMP responsiveness. Yet, these cells can be gated to become responsive by neighbor cell damage. Laser ablation of small cell clusters strongly upregulates PRR expression in their vicinity, and elevated receptor expression is sufficient to induce responsiveness in non-responsive cells. Finally, localized damage also leads to immune responses to otherwise non-immunogenic, beneficial bacteria. Damage-gating is overridden by receptor overexpression, which antagonizes colonization. Our findings that cellular damage can "switch on" local immune responses helps to conceptualize how MAMP perception can be used despite the presence of microbial patterns in the soil.

Keywords: Arabidopsis; damage-gating; localized response; microbe patterns; pattern-recognition receptors; root immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / growth & development
  • Arabidopsis / immunology*
  • Arabidopsis / microbiology
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins / metabolism
  • Arabidopsis Proteins / radiation effects
  • Ascorbate Peroxidases / metabolism
  • Ascorbate Peroxidases / radiation effects
  • Flagellin / pharmacology
  • Gene Expression Regulation, Plant / drug effects
  • Gene Expression Regulation, Plant / radiation effects
  • Laser Therapy / methods
  • Membrane Proteins / metabolism
  • Membrane Proteins / radiation effects
  • Microscopy, Confocal
  • Plant Diseases / immunology*
  • Plant Diseases / microbiology*
  • Plant Roots / growth & development
  • Plant Roots / immunology*
  • Plant Roots / microbiology
  • Plant Roots / radiation effects
  • Protein Kinases / metabolism
  • Protein Kinases / radiation effects
  • Receptors, Pattern Recognition / metabolism*
  • Receptors, Pattern Recognition / radiation effects
  • Signal Transduction / drug effects
  • Signal Transduction / radiation effects
  • Time-Lapse Imaging


  • Arabidopsis Proteins
  • Membrane Proteins
  • Receptors, Pattern Recognition
  • Flagellin
  • APX5 protein, Arabidopsis
  • Ascorbate Peroxidases
  • FRK1 protein, Arabidopsis
  • Protein Kinases