title: Alterations of iron distribution in Arabidopsis tissues infected by Dickeya dadantii.
abstract: Dickeya dadantii is a plant-pathogenic enterobacterium responsible for plant soft rot disease in a wide range of hosts, including the model plant Arabidopsis thaliana. Iron distribution in infected A. thaliana was investigated at the cellular scale using the Perls'-diaminobenzidine-H2 O2 (PDH) method. Iron visualization during infection reveals a loss of iron from cellular compartments and plant cell walls. During symptom progression, two distinct zones are clearly visible: a macerated zone displaying weak iron content and a healthy zone displaying strong iron content. Immunolabelling of cell wall methylated pectin shows that pectin degradation is correlated with iron release from cell walls, indicating a strong relationship between cell wall integrity and iron in plant tissues. Using a D. dadantii lipopolysaccharide antibody, we show that bacteria are restricted to the infected tissue, and that they accumulate iron in planta. In conclusion, weak iron content is strictly correlated with bacterial cell localization in the infected tissues, indicating a crucial role of this element during the interaction. This is the first report of iron localization at the cellular level during a plant-microbe interaction and shows that PDH is a method of choice in this type of investigation.
authors.affiliation: AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026, Versailles, France; Sorbonne Universités, UPMC, Université Paris 06, UFR927, F-75005, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Aznar
authors.forename: Oriane
authors.initials: O
authors.lastname: Patrit
authors.forename: Adeline
authors.initials: A
authors.lastname: Berger
authors.forename: Alia
authors.initials: A
authors.lastname: Dellagi
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000382:microbiology* / Q000648:ultrastructure; D002473:Cell Wall / Q000382:microbiology; D004755:Enterobacteriaceae / Q000378:metabolism*; D005293:Ferritins / Q000378:metabolism; D007501:Iron / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000378:metabolism / Q000382:microbiology / Q000648:ultrastructure; D021381:Protein Transport
chemical_list: D005293:Ferritins; D007501:Iron
keywords: Arabidopsis; Dickeya dadantii; Perls'-DAB-H2O2; histochemical staining; infection; iron