title: The Phytophthora parasitica RXLR effector penetration-specific effector 1 favours Arabidopsis thaliana infection by interfering with auxin physiology.
abstract: Pathogenic oomycetes have evolved RXLR effectors to thwart plant defense mechanisms and invade host tissues. We analysed the function of one of these effectors (Penetration-Specific Effector 1 (PSE1)) whose transcript is transiently accumulated during penetration of host roots by the oomycete Phytophthora parasitica. Expression of PSE1 protein in tobacco (Nicotiana tabacum and Nicotiana benthamiana) leaves and in Arabidopsis thaliana plants was used to assess the role of this effector in plant physiology and in interactions with pathogens. A pharmacological approach and marker lines were used to charcterize the A. thaliana phenotypes. Expression of PSE1 in A. thaliana led to developmental perturbations associated with low concentrations of auxin at the root apex. This modification of auxin content was associated with an altered distribution of the PIN4 and PIN7 auxin efflux carriers. The PSE1 protein facilitated plant infection: it suppressed plant cell death activated by Pseudomonas syringae avirulence gene AvrPto and Phytophthora cryptogea elicitin cryptogein in tobacco and exacerbated disease symptoms upon inoculation of transgenic A. thaliana plantlets with P. parasitica in an auxin-dependant manner. We propose that P. parasitica secretes the PSE1 protein during the penetration process to favour the infection by locally modulating the auxin content. These results support the hypothesis that effectors from plant pathogens may act on a limited set of targets, including hormones.
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Edouard
authors.initials: E
authors.lastname: Evangelisti
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Govetto
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Naïma
authors.initials: N
authors.lastname: Minet-Kebdani
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Kuhn
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Attard
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Ponchet
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Panabières
authors.affiliation: UMR Institut Sophia Agrobiotech, INRA 1355 - CNRS 7254 - Université de Nice Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Gourgues
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000469:parasitology* / Q000502:physiology*; D016923:Cell Death; D005656:Fungal Proteins / Q000378:metabolism; D005816:Genetic Complementation Test; D007210:Indoleacetic Acids / Q000378:metabolism*; D010641:Phenotype; D010838:Phytophthora / Q000378:metabolism*; D018517:Plant Roots / Q000469:parasitology; D030821:Plants, Genetically Modified; D011506:Proteins / Q000378:metabolism*; D011549:Pseudomonas / Q000502:physiology
chemical_list: D005656:Fungal Proteins; D007210:Indoleacetic Acids; D011506:Proteins; C061032:cryptogein protein, Phytophthora cryptogea