title: Characterization of the hrpZ gene from Pseudomonas syringae pv. maculicola M2.
abstract: Pseudomonas syringae pv. maculicola is a natural pathogen of members of the Brassicaceae plant family. Using a transposon-based mutagenesis strategy in Pseudomonas syringaepv. maculicola M2 (PsmM2), we conducted a genetic screen to identify mutants that were capable of growing in M9 medium supplemented with a crude extract from the leaves of Arabidopsis thaliana. A mutant containing a transposon insertion in the hrpZ gene (PsmMut8) was unable to infect adult plants from Arabidopsis thaliana or Brassica oleracea, suggesting a loss of pathogenicity. The promotorless cat reporter present in the gene trap was expressed if PsmMut8 was grown in minimal medium (M9) supplemented with the leaf extract but not if grown in normal rich medium (KB). We conducted phylogenetic analysis using hrpAZB genes, showing the classical 5-clade distribution, and nucleotide diversity analysis, showing the putative position for selective pressure in this operon. Our results indicate that the hrpAZB operon from Pseudomonas syringaepv. maculicola M2 is necessary for its pathogenicity and that its diversity would be under host-mediated diversifying selection.
authors.affiliation: Instituto Tecnológico Superior de Irapuato Plantel Abasolo, Guanajuato, México .
authors.forename: César
authors.initials: C
authors.lastname: Álvarez-Mejía
authors.affiliation: Departamento de Ingeniería Genética de Plantas, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Guanajuato, México .
authors.forename: Dalia
authors.initials: D
authors.lastname: Rodríguez-Ríos
authors.affiliation: División de Ciencias de la Vida, Universidad de Guanajuato, Guanajuato, México .
authors.forename: Gustavo
authors.initials: G
authors.lastname: Hernández-Guzmán
authors.affiliation: Instituto Tecnológico Superior de Irapuato, Guanajuato, México .
authors.forename: Varinia
authors.initials: V
authors.lastname: López-Ramírez
authors.affiliation: Departamento de Plásticos en Agricultura, Centro de Investigación en Química Aplicada, Coahuila, México.
authors.forename: Humberto
authors.initials: H
authors.lastname: Valenzuela-Soto
authors.affiliation: Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F. México, México .
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Marsch
mesh_terms: D017360:Arabidopsis / Q000382:microbiology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D001937:Brassica / Q000382:microbiology*; D003470:Culture Media; D004251:DNA Transposable Elements / Q000235:genetics; D005798:Genes, Bacterial; D009154:Mutation / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D044224:Pseudomonas syringae / Q000235:genetics* / Q000472:pathogenicity*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D003470:Culture Media; D004251:DNA Transposable Elements; C087295:HrpZ protein, Pseudomonas syringae
keywords: Tn5; hrpZ; mutant non-pathogenic; phylogenetic; transmid