Co-option of a default secretory pathway for plant immune responses

Nature. 2008 Feb 14;451(7180):835-40. doi: 10.1038/nature06545.

Abstract

Cell-autonomous immunity is widespread in plant-fungus interactions and terminates fungal pathogenesis either at the cell surface or after pathogen entry. Although post-invasive resistance responses typically coincide with a self-contained cell death of plant cells undergoing attack by parasites, these cells survive pre-invasive defence. Mutational analysis in Arabidopsis identified PEN1 syntaxin as one component of two pre-invasive resistance pathways against ascomycete powdery mildew fungi. Here we show that plasma-membrane-resident PEN1 promiscuously forms SDS-resistant soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) complexes together with the SNAP33 adaptor and a subset of vesicle-associated membrane proteins (VAMPs). PEN1-dependent disease resistance acts in vivo mainly through two functionally redundant VAMP72 subfamily members, VAMP721 and VAMP722. Unexpectedly, the same two VAMP proteins also operate redundantly in a default secretory pathway, suggesting dual functions in separate biological processes owing to evolutionary co-option of the default pathway for plant immunity. The disease resistance function of the secretory PEN1-SNAP33-VAMP721/722 complex and the pathogen-induced subcellular dynamics of its components are mechanistically reminiscent of immunological synapse formation in vertebrates, enabling execution of immune responses through focal secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • Arabidopsis / genetics
  • Arabidopsis / immunology*
  • Arabidopsis / microbiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Ascomycota / physiology
  • N-Glycosyl Hydrolases / genetics
  • N-Glycosyl Hydrolases / metabolism
  • Qa-SNARE Proteins / genetics
  • Qa-SNARE Proteins / metabolism
  • SNARE Proteins / genetics
  • SNARE Proteins / metabolism

Substances

  • ATP-Binding Cassette Transporters
  • Arabidopsis Proteins
  • PDR8 protein, Arabidopsis
  • PEN1 protein, Arabidopsis
  • Qa-SNARE Proteins
  • SNARE Proteins
  • N-Glycosyl Hydrolases
  • PEN2 protein, Arabidopsis