ESCRT-I mediates FLS2 endosomal sorting and plant immunity

PLoS Genet. 2013;9(12):e1004035. doi: 10.1371/journal.pgen.1004035. Epub 2013 Dec 26.

Abstract

The plant immune receptor FLAGELLIN SENSING 2 (FLS2) is present at the plasma membrane and is internalized following activation of its ligand flagellin (flg22). We show that ENDOSOMAL SORTING COMPLEX REQUIRED FOR TRANSPORT (ESCRT)-I subunits play roles in FLS2 endocytosis in Arabidopsis. VPS37-1 co-localizes with FLS2 at endosomes and immunoprecipitates with the receptor upon flg22 elicitation. Vps37-1 mutants are reduced in flg22-induced FLS2 endosomes but not in endosomes labeled by Rab5 GTPases suggesting a defect in FLS2 trafficking rather than formation of endosomes. FLS2 localizes to the lumen of multivesicular bodies, but this is altered in vps37-1 mutants indicating compromised endosomal sorting of FLS2 by ESCRT-I loss-of-function. VPS37-1 and VPS28-2 are critical for immunity against bacterial infection through a role in stomatal closure. Our findings identify that VPS37-1, and likewise VPS28-2, regulate late FLS2 endosomal sorting and reveals that ESCRT-I is critical for flg22-activated stomatal defenses involved in plant immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / immunology
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cell Membrane / genetics
  • Cell Membrane / metabolism
  • Endocytosis / genetics*
  • Endosomal Sorting Complexes Required for Transport / genetics*
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Endosomes / genetics
  • Endosomes / metabolism
  • Plant Immunity / genetics*
  • Protein Kinases / genetics*
  • Protein Kinases / metabolism
  • rab5 GTP-Binding Proteins / genetics

Substances

  • Arabidopsis Proteins
  • Endosomal Sorting Complexes Required for Transport
  • Protein Kinases
  • FLS2 protein, Arabidopsis
  • rab5 GTP-Binding Proteins

Grants and funding

TS and MB were supported by a grant of the Deutsche Forschungsgemeinschaft (SPP1212; postdoctoral fellow), SSa by a fellowship of the Max-Planck-Institute for Plant Breeding Research (Cologne), and research by SR is supported by the Gatsby Charitable Foundation and a grant by the European Research Council (ERC STORM). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.