Molecular identification and characterization of the tomato flagellin receptor LeFLS2, an orthologue of Arabidopsis FLS2 exhibiting characteristically different perception specificities.
Bacterial flagellin is known to stimulate host immune responses in mammals and plants. In Arabidopsis thaliana, the receptor kinase FLS2 mediates flagellin perception through physical interaction with a highly conserved epitope in the N-terminus of flagellin, represented by the peptide flg22 derived from Pseudomonas syringae. The peptide flg22 is highly active as an elicitor in many plant species. In contrast, a shortened version of the same epitope derived from Escherichia coli, flg15(E coli), is highly active as an elicitor in tomato but not in A. thaliana or Nicotiana benthamiana. Here, we make use of these species-specific differences in flagellin perception abilities to identify LeFLS2 as the flagellin receptor in tomato. LeFLS2 is most closely related to AtFLS2, indicating that it may represent the flagellin receptor of tomato. Expression of the LeFLS2 gene in Arabidopsis did not result in accumulation of its corresponding gene product, as indicated by experiments with LeFLS2-GFP fusions. In contrast, expression of LeFLS2-GFP fusions in N. benthamiana, a species that, like tomato, belongs to the Solanaceae, was obviously functional. N. benthamiana plants transiently expressing a LeFLS2-GFP fusion acquired responsiveness to flg15(E coli) to which they are normally unresponsive. Thus, LeFLS2 encodes a functional, specific flagellin receptor, the first to be identified in a plant family other than the Brassicaceae.
Robatzek
Silke
S
Zürich-Basel Plant Science Center, Botanical Institute, University Basel, Hebelstrasse 1, Basel, 4056, Switzerland. robatzek@mpiz-koeln.mpg.de
Bittel
Pascal
P
Chinchilla
Delphine
D
Köchner
Petra
P
Felix
Georg
G
Shiu
Shin-Han
SH
Boller
Thomas
T
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000502:physiology; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D004926:Escherichia coli / Q000502:physiology; D029968:Escherichia coli Proteins / Q000502:physiology; D005408:Flagellin / Q000378:metabolism*; D017930:Genes, Reporter; D018551:Solanum lycopersicum / Q000235:genetics*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics*; D044224:Pseudomonas syringae / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D005408:Flagellin; D011494:Protein Kinases; C411853:FLS2 protein, Arabidopsis