title: The bacterial lipopeptide surfactin targets the lipid fraction of the plant plasma membrane to trigger immune-related defence responses.
abstract: The lipopeptide surfactin secreted by plant-beneficial bacilli has crucial biological functions among which the ability to stimulate immune-related responses in host tissues. This phenomenon is important for biological control of plant diseases but its molecular basis is still poorly understood. In this work, we used various approaches to study the mechanism governing the perception of this biosurfactant at the plant cell surface. Combining data on oxidative burst induction in tobacco cells, structure/activity relationship, competitive inhibition, insertion kinetics within plant membranes and thermodynamic determination of binding parameters on model membranes globally indicates that surfactin perception relies on a lipid-driven process at the plasma membrane level. Such a sensor role of the lipid bilayer is quite uncommon considering that plant basal immunity is usually triggered upon recognition of microbial molecular patterns by high-affinity proteic receptors.
authors.affiliation: Walloon Center for Industrial Biology             Unité de Chimie Biologique Industrielle, University of Liège/Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Henry
authors.forename: Magali
authors.initials: M
authors.lastname: Deleu
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jourdan
authors.forename: Philippe
authors.initials: P
authors.lastname: Thonart
authors.forename: Marc
authors.initials: M
authors.lastname: Ongena
mesh_terms: D001407:Bacillus / Q000737:chemistry* / Q000276:immunology*; D002462:Cell Membrane / Q000187:drug effects*; D055666:Lipopeptides / Q000302:isolation & purification / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism*; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000302:isolation & purification / Q000378:metabolism*; D014026:Nicotiana / Q000276:immunology* / Q000382:microbiology*
chemical_list: D055666:Lipopeptides; D008563:Membrane Lipids; D010456:Peptides, Cyclic; C009365:surfactin peptide