The DeltafliD mutant of Pseudomonas syringae pv. tabaci, which secretes flagellin monomers, induces a strong hypersensitive reaction (HR) in non-host tomato cells.
To investigate the role of flagella and monomer flagellin in the interaction between Pseudomonas syringae pv. tabaci and plants, non-polar fliC and fliD mutants were produced. The ORFs for fliC and fliD are deleted in the DeltafliC and DeltafliD mutants, respectively. Both mutants lost all flagella and were non-motile. The DeltafliC mutant did not produce flagellin, whereas the DeltafliD mutant, which lacks the HAP2 protein, secreted large amounts of monomer flagellin into the culture medium. Inoculation of non-host tomato leaves with wild-type P. syringae pv. tabaci or the DeltafliD mutant induced a hypersensitive reaction (HR), whereas the DeltafliC mutant propagated and caused characteristic symptom-like changes. In tomato cells in suspension culture, wild-type P. syringae pv. tabaci induced slight, visible HR-like changes. The DeltafliC mutant did not induce HR, but the DeltafliD mutant induced a remarkably strong HR. Expression of the hsr203J gene was rapidly and strongly induced by inoculation with the DeltafliD mutant, compared to inoculation with wild-type P. syringae pv. tabaci. Furthermore, introduction of the fliC gene into the DeltafliC mutant restored motility and HR-inducing ability in tomato. These results, together with our previous study, suggest that the flagellin monomer of pv. tabaci acts as a strong elicitor to induce HR-associated cell death in non-host tomato cells.
Shimizu
R
R
Laboratory of Plant Pathology and Genetic Engineering, Faculty of Agriculture, Okayama University, 1-1-1 Tsushima-naka, 700-8530 Okayama, Japan.
Taguchi
F
F
Marutani
M
M
Mukaihara
T
T
Inagaki
Y
Y
Toyoda
K
K
Shiraishi
T
T
Ichinose
Y
Y
D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001483:Base Sequence; D002478:Cells, Cultured; D003470:Culture Media / Q000032:analysis; D005407:Flagella / Q000378:metabolism; D005408:Flagellin / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D005798:Genes, Bacterial; D018551:Solanum lycopersicum / Q000166:cytology / Q000382:microbiology*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010935:Plant Diseases / Q000382:microbiology; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D003470:Culture Media; D011994:Recombinant Proteins; C075462:harpin protein, Erwinia amylovora; D005408:Flagellin; C076733:FlaD protein, Bacteria; C087295:HrpZ protein, Pseudomonas syringae