Zavala, DiegoFuenzalida, IsabelGangas, María VictoriaPeppino Margutti, MicaelaBartoli, ClaudiaRoux, FabriceMeneses, ClaudioHerrera Vásquez, ArielBlanco Herrera, Francisca2022-07-062022-07-062022-03Microorganisms Volume 10, Issue 4April 2022 Article number 7072076-2607https://repositorio.unab.cl/xmlui/handle/ria/23202Indexación: ScopusEnvironmental fluctuations such as increased temperature, water availability, and air CO2 concentration triggered by climate change influence plant disease dynamics by affecting hosts, pathogens, and their interactions. Here, we describe a newly discovered Pseudomonas syringae strain found in a natural population of Arabidopsis thaliana collected from the southwest of France. This strain, called Psy RAYR-BL, is highly virulent on natural Arabidopsis accessions, Arabidopsis model accession Columbia 0, and tobacco plants. Despite the severe disease phenotype caused by the Psy RAYR-BL strain, we identified a reduced repertoire of putative Type III virulence effectors by genomic sequencing compared to P. syringae pv tomato (Pst) DC3000. Furthermore, hopBJ1Psy is found exclusively on the Psy RAYR-BL genome but not in the Pst DC3000 genome. The plant expression of HopBJ1Psy induces ROS accumulation and cell death. In addition, HopBJ1Psy participates as a virulence factor in this plant-pathogen interaction, likely explaining the severity of the disease symptoms. This research describes the characterization of a newly discovered plant pathogen strain and possible virulence mechanisms underlying the infection process shaped by natural and changing environmental conditions. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.enArabidopsis thalianaDisease emergenceHopBJ1Pathogenic reservoirsPseudomonas syringaeT3SSVirulence factorArtículoAtribución 4.0 Internacional (CC BY 4.0)10.3390/microorganisms10040707