Bacterial medium-chain 3-hydroxy fatty acid metabolites trigger immunity in Arabidopsis plants

Science. 2019 Apr 12;364(6436):178-181. doi: 10.1126/science.aau1279.


In plants, cell-surface immune receptors sense molecular non-self-signatures. Lipid A of Gram-negative bacterial lipopolysaccharide is considered such a non-self-signature. The receptor kinase LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION (LORE) mediates plant immune responses to Pseudomonas and Xanthomonas but not enterobacterial lipid A or lipopolysaccharide preparations. Here, we demonstrate that synthetic and bacterial lipopolysaccharide-copurified medium-chain 3-hydroxy fatty acid (mc-3-OH-FA) metabolites elicit LORE-dependent immunity. The mc-3-OH-FAs are sensed in a chain length- and hydroxylation-specific manner, with free (R)-3-hydroxydecanoic acid [(R)-3-OH-C10:0] representing the strongest immune elicitor. By contrast, bacterial compounds comprising mc-3-OH-acyl building blocks but devoid of free mc-3-OH-FAs-including lipid A or lipopolysaccharide, rhamnolipids, lipopeptides, and acyl-homoserine-lactones-do not trigger LORE-dependent responses. Hence, plants sense low-complexity bacterial metabolites to trigger immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyl-Butyrolactones / metabolism
  • Arabidopsis / immunology*
  • Arabidopsis / microbiology*
  • Decanoic Acids / chemistry
  • Decanoic Acids / metabolism*
  • Glycolipids / metabolism
  • Lipid A / metabolism
  • Lipopeptides / metabolism
  • Pseudomonas aeruginosa / metabolism*


  • Acyl-Butyrolactones
  • Decanoic Acids
  • Glycolipids
  • Lipid A
  • Lipopeptides
  • rhamnolipid
  • myrmicacin