title: A bacterial cysteine protease effector protein interferes with photosynthesis to suppress plant innate immune responses.
abstract: The bacterial pathogen Pseudomonas syringae pv tomato DC3000 suppresses plant innate immunity with effector proteins injected by a type III secretion system (T3SS). The cysteine protease effector HopN1, which reduces the ability of DC3000 to elicit programmed cell death in non-host tobacco, was found to also suppress the production of defence-associated reactive oxygen species (ROS) and callose when delivered by Pseudomonas fluorescens heterologously expressing a P. syringae T3SS. Purified His(6) -tagged HopN1 was used to identify tomato PsbQ, a member of the oxygen evolving complex of photosystem II (PSII), as an interacting protein. HopN1 localized to chloroplasts and both degraded PsbQ and inhibited PSII activity in chloroplast preparations, whereas a HopN1(D299A) non-catalytic mutant lost these abilities. Gene silencing of NtPsbQ in tobacco compromised ROS production and programmed cell death by DC3000. Our data reveal PsbQ as a contributor to plant immunity responses and a target for pathogen suppression.
authors.affiliation: Centro de Biotecnología y Genómica de Plantas (CBGP). Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria., Parque Científico y Tecnológico de la UPM. Campus de Montegancedo. 28223 Pozuelo de Alarcón, Madrid, Spain.
authors.forename: José J
authors.initials: JJ
authors.lastname: Rodríguez-Herva
authors.forename: Pablo
authors.initials: P
authors.lastname: González-Melendi
authors.forename: Raquel
authors.initials: R
authors.lastname: Cuartas-Lanza
authors.forename: María
authors.initials: M
authors.lastname: Antúnez-Lamas
authors.forename: Isabel
authors.initials: I
authors.lastname: Río-Alvarez
authors.forename: Ziduo
authors.initials: Z
authors.lastname: Li
authors.forename: Gema
authors.initials: G
authors.lastname: López-Torrejón
authors.forename: Isabel
authors.initials: I
authors.lastname: Díaz
authors.forename: Juan C
authors.initials: JC
authors.lastname: Del Pozo
authors.forename: Suma
authors.initials: S
authors.lastname: Chakravarthy
authors.forename: Alan
authors.initials: A
authors.lastname: Collmer
authors.forename: Pablo
authors.initials: P
authors.lastname: Rodríguez-Palenzuela
authors.forename: Emilia
authors.initials: E
authors.lastname: López-Solanilla
mesh_terms: D017209:Apoptosis; D001426:Bacterial Proteins / Q000378:metabolism; D057056:Cysteine Proteases / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D057131:Immune Evasion; D007113:Immunity, Innate; D018551:Solanum lycopersicum / Q000276:immunology / Q000382:microbiology*; D010788:Photosynthesis; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D025941:Protein Interaction Mapping; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000472:pathogenicity; D044224:Pseudomonas syringae / Q000201:enzymology* / Q000472:pathogenicity; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D045332:Photosystem II Protein Complex; D017382:Reactive Oxygen Species; D037521:Virulence Factors; D057056:Cysteine Proteases