Analysis of flagellin perception mediated by flg22 receptor OsFLS2 in rice

Mol Plant Microbe Interact. 2008 Dec;21(12):1635-42. doi: 10.1094/MPMI-21-12-1635.


Plants have sensitive perception systems that recognize various pathogen-derived molecules. We previously reported that rice detects flagellin from a rice-incompatible strain of gram-negative phytopathogenic bacterium, Acidovorax avenae, which induces subsequent immune responses involving cell death. The mechanism of flagellin perception in rice, however, has remained obscure. In this study, we found that flg22, a peptide derived from the flagellin N-terminus, induced weak immune responses without cell death in cultured rice cells. To elucidate the mechanism by which flg22 induced signaling in rice, we characterized OsFLS2, the rice ortholog of AtFLS2, which mediates flg22 perception. Heterologous expression of OsFLS2 functions in Arabidopsis, showing the conservation of the flg22 signaling pathway across divergent plant taxa. OsFLS2-overexpressing rice cultured cells generated stronger immune responses with the induction of cell death following stimulation with flg22 and flagellin. However, examination of the growth rate of the compatible strain in inoculated OsFLS2-overexpressing rice could not confirm bacterial growth suppression compared with wild-type rice. These results suggest that rice possesses a conserved flagellin perception system utilizing the FLS2 receptor which, when upregulated, hardly affects resistance against compatible A. avenae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Cell Death*
  • Cells, Cultured
  • Comamonadaceae / immunology
  • Comamonadaceae / pathogenicity
  • Flagellin / immunology
  • Flagellin / metabolism*
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Hydrogen Peroxide / metabolism
  • Immunity, Innate
  • Molecular Sequence Data
  • Oryza / genetics*
  • Oryza / immunology
  • Oryza / metabolism
  • Oryza / microbiology
  • Plant Diseases / genetics
  • Plant Diseases / immunology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / immunology
  • Plants, Genetically Modified / metabolism
  • Plants, Genetically Modified / microbiology
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • RNA, Plant / genetics
  • Sequence Alignment
  • Substrate Specificity
  • Transformation, Genetic


  • Arabidopsis Proteins
  • Plant Proteins
  • RNA, Plant
  • Flagellin
  • Hydrogen Peroxide
  • Protein Kinases
  • FLS2 protein, Arabidopsis