title: Both the Jasmonic Acid and the Salicylic Acid Pathways Contribute to Resistance to the Biotrophic Clubroot Agent Plasmodiophora brassicae in Arabidopsis.
abstract: The role of salicylic acid (SA) and jasmonic acid (JA) signaling in resistance to root pathogens has been poorly documented. We assessed the contribution of SA and JA to basal and partial resistance of Arabidopsis to the biotrophic clubroot agent Plasmodiophora brassicae. SA and JA levels as well as the expression of the SA-responsive genes PR2 and PR5 and the JA-responsive genes ARGAH2 and THI2.1 were monitored in infected roots of the accessions Col-0 (susceptible) and Bur-0 (partially resistant). SA signaling was activated in Bur-0 but not in Col-0. The JA pathway was weakly activated in Bur-0 but was strongly induced in Col-0. The contribution of both pathways to clubroot resistance was then assessed using exogenous phytohormone application and mutants affected in SA or JA signaling. Exogenous SA treatment decreased clubroot symptoms in the two Arabidopsis accessions, whereas JA treatment reduced clubroot symptoms only in Col-0. The cpr5-2 mutant, in which SA responses are constitutively induced, was more resistant to clubroot than the corresponding wild type, and the JA signaling-deficient mutant jar1 was more susceptible. Finally, we showed that the JA-mediated induction of NATA1 drove N(δ)-acetylornithine biosynthesis in infected Col-0 roots. The 35S::NATA1 and nata1 lines displayed reduced or enhanced clubroot symptoms, respectively, thus suggesting that in Col-0 this pathway was involved in the JA-mediated basal clubroot resistance. Overall, our data support the idea that, depending on the Arabidopsis accession, both SA and JA signaling can play a role in partial inhibition of clubroot development in compatible interactions with P. brassicae.
authors.affiliation: INRA, UMR1349 IGEPP, F-35653 Le Rheu, France antoine.gravot@univ-rennes1.fr.
authors.forename: Séverine
authors.initials: S
authors.lastname: Lemarié
authors.affiliation: INRA, UMR1349 IGEPP, F-35653 Le Rheu, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Robert-Seilaniantz
authors.affiliation: INRA, UMR1349 IGEPP, F-35653 Le Rheu, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Lariagon
authors.affiliation: INRA, UMR1349 IGEPP, F-35653 Le Rheu, France.
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Lemoine
authors.affiliation: Plateau de Profilage Métabolique et Métabolomique (P2M2) Centre de Recherche Angers Nantes BIA, INRA de Rennes, F-35653 Le Rheu, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Marnet
authors.affiliation: AGROCAMPUS OUEST, UMR1349 IGEPP, F-35000 Rennes, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Jubault
authors.affiliation: AGROCAMPUS OUEST, UMR1349 IGEPP, F-35000 Rennes, France.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Manzanares-Dauleux
authors.affiliation: Université Rennes 1, UMR1349 IGEPP, F-35000 Rennes, France antoine.gravot@univ-rennes1.fr.
authors.forename: Antoine
authors.initials: A
authors.lastname: Gravot
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000469:parasitology*; D003517:Cyclopentanes / Q000378:metabolism*; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology / Q000469:parasitology; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D056909:Plasmodiophorida / Q000502:physiology*; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; D020156:Salicylic Acid
keywords: Arabidopsis thaliana; Clubroot; Jasmonic acid; Partial resistance; Plasmodiophora brassicae; Salicylic acid