title: Salmonella enterica strains belonging to O serogroup 1,3,19 induce chlorosis and wilting of Arabidopsis thaliana leaves.
abstract: The number of outbreaks and illness linked to the consumption of contaminated salad leaves have increased dramatically in the last decade. Escherichia coli and Salmonella enterica are the most common food-borne pathogens linked to consumption of fresh produce. Different serovars of S. enterica subspecies enterica have been shown to bind the surface of salad leaves, to exhibit tropism towards the stomata and to invade leaves and reach the underlying mesophyll. However the consequences of leaf invasion are not known. Here we show that following infiltration, serovars Typhimurium, Enteritidis, Heidelberg and Agona, as well as strains of S. enterica subspecies arizonae and diarizonae, survive in the mesophyll of Arabidopsis thaliana leaves but induce neither leaf chlorosis nor wilting. In contrast, S. Senftenberg induced strong leaf wilting 4 days post infiltration in A. thaliana accession Col-0 but not in accession Ws-0. Dead S. Senftenberg and bacterial lysates also induced leaf wilting. We found that mutations in the Arabidopsis pathogen associated molecular pattern (PAMP) recognition receptors (PRRs) FLS2, which recognizes flagellin, and EFR, which recognizes the bacterial elongation factor EF-Tu, had no effect on the wilting response of A. thaliana to S. Senftenberg. Infiltration of A. thaliana leaves with serovars Cannstatt, Krefeld and Liverpool, which like Senftenberg belong to Salmonella serogroup E(4) (O:1,3,19), also resulted in rapid leaf wilting, while all tested rough S. Senftenberg strains (lacking the O antigen) failed to elicit leaf wilting. These results suggest that the Salmonella O antigen 1,3,19 specifically triggers leaf chlorosis and wilting in A. thaliana.
authors.affiliation: Divisions of Cell and Molecular Biology, Imperial College London, London, UK.
authors.forename: Cedric N
authors.initials: CN
authors.lastname: Berger
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Brown
authors.forename: Robert K
authors.initials: RK
authors.lastname: Shaw
authors.forename: Florencia
authors.initials: F
authors.lastname: Minuzzi
authors.forename: Bart
authors.initials: B
authors.lastname: Feys
authors.forename: Gad
authors.initials: G
authors.lastname: Frankel
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics; D005408:Flagellin / Q000378:metabolism; D014644:Genetic Variation; D019081:O Antigens / Q000378:metabolism; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology*; D011494:Protein Kinases / Q000235:genetics; D051192:Receptors, Pattern Recognition / Q000235:genetics; D019779:Salmonella enterica / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D029681:Arabidopsis Proteins; D019081:O Antigens; D051192:Receptors, Pattern Recognition; D005408:Flagellin; D011494:Protein Kinases; C411853:FLS2 protein, Arabidopsis; D010444:Peptide Elongation Factor Tu