title: Deciphering the responses of root border-like cells of Arabidopsis and flax to pathogen-derived elicitors.
abstract: Plant pathogens including fungi and bacteria cause many of the most serious crop diseases. The plant innate immune response is triggered upon recognition of microbe-associated molecular patterns (MAMPs) such as flagellin22 and peptidoglycan. To date, very little is known of MAMP-mediated responses in roots. Root border cells are cells that originate from root caps and are released individually into the rhizosphere. Root tips of Arabidopsis (Arabidopsis thaliana) and flax (Linum usitatissimum) release cells known as "border-like cells." Whereas root border cells of pea (Pisum sativum) are clearly involved in defense against fungal pathogens, the function of border-like cells remains to be established. In this study, we have investigated the responses of root border-like cells of Arabidopsis and flax to flagellin22 and peptidoglycan. We found that both MAMPs triggered a rapid oxidative burst in root border-like cells of both species. The production of reactive oxygen species was accompanied by modifications in the cell wall distribution of extensin epitopes. Extensins are hydroxyproline-rich glycoproteins that can be cross linked by hydrogen peroxide to enhance the mechanical strength of the cell wall. In addition, both MAMPs also caused deposition of callose, a well-known marker of MAMP-elicited defense. Furthermore, flagellin22 induced the overexpression of genes involved in the plant immune response in root border-like cells of Arabidopsis. Our findings demonstrate that root border-like cells of flax and Arabidopsis are able to perceive an elicitation and activate defense responses. We also show that cell wall extensin is involved in the innate immunity response of root border-like cells.
authors.affiliation: Laboratoire Glycobiologie et Matrice Extracellulaire Végétale, Equipe d'Accueil 4358, Grand Réseau de Recherche Végétal, Agronomie, Sols et Innovation Université de Rouen, 76821 Mont Saint Aignan, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Plancot
authors.forename: Catherine
authors.initials: C
authors.lastname: Santaella
authors.forename: Rim
authors.initials: R
authors.lastname: Jaber
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Kiefer-Meyer
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Follet-Gueye
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leprince
authors.forename: Isabelle
authors.initials: I
authors.lastname: Gattin
authors.forename: Céline
authors.initials: C
authors.lastname: Souc
authors.forename: Azeddine
authors.initials: A
authors.lastname: Driouich
authors.forename: Maïté
authors.initials: M
authors.lastname: Vicré-Gibouin
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D015415:Biomarkers / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002473:Cell Wall / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure; D000939:Epitopes / Q000276:immunology; D005408:Flagellin / Q000494:pharmacology; D019597:Flax / Q000166:cytology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005936:Glucans / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology; D010457:Peptidoglycan / Q000494:pharmacology; D059828:Plant Cells / Q000187:drug effects / Q000276:immunology* / Q000382:microbiology* / Q000648:ultrastructure; D010940:Plant Proteins / Q000276:immunology; D018517:Plant Roots / Q000166:cytology* / Q000187:drug effects / Q000276:immunology / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D051192:Receptors, Pattern Recognition / Q000276:immunology; D013997:Time Factors
chemical_list: D015415:Biomarkers; D000939:Epitopes; D005936:Glucans; D006023:Glycoproteins; D010457:Peptidoglycan; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D051192:Receptors, Pattern Recognition; C005488:extensin protein, plant; D005408:Flagellin; C048306:callose