title: CitB is required for full virulence of Xanthomonas oryzae pv. oryzae.
abstract: To identify novel virulence associated genes in Xanthomonas oryzae pv. oryzae (Xoo), a Xoo isolate (XooIR42), obtained from north of Iran, was selected to generate a mini-Tn5 transposon mutation library. One mutant (XooM176) that indicated reduced virulence on rice plants, while grew similar to wild type was selected. This mutant had an insertion in a coding region with 96% amino acid identity to a response regulator of Xoo KACC10331, citB (Xoo_RS12710). Genome analysis of Xoo KACC10331 indicated several genes including a flagelin protein (FlgL) and a chemotaxis protein (Xoo_RS12720) which were identified as virulence genes 4297 and 1403 nucleotides from the citB, respectively. The swarming motility, resistance to hydrogen peroxide, induced a hypersensitive response, in planta growth and pathogenicity were reduced in XooM176 mutant compared to that of wild-type. A plasmid containing the full citB gene of Xoo KACC10331was sufficient to complement the XooM176 mutant for lesion formation and resistance to hydrogen peroxide. We therefore propose that Xoo requires CitB for full pathogenicity in rice plants and also for protection against oxidative stress.
authors.affiliation: Laboratory of Phytopathology, Department of Crop Protection, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Masood
authors.initials: M
authors.lastname: Sahebi
authors.affiliation: Laboratory of Phytopathology, Department of Crop Protection, Ferdowsi University of Mashhad, Mashhad, Iran.
authors.forename: Elaheh
authors.initials: E
authors.lastname: Taheri
authors.affiliation: Laboratory of Phytopathology, Department of Crop Protection, Ferdowsi University of Mashhad, Mashhad, Iran. starighi@um.ac.ir.|Laboratory of Plant Pathology, Department of Crop Protection, Ferdowsi University of Mashhad, Mashhad, Iran. starighi@um.ac.ir.
authors.forename: Saeed
authors.initials: S
authors.lastname: Tarighi
mesh_terms: D004251:DNA Transposable Elements; D004361:Drug Tolerance; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide / Q000633:toxicity; D007492:Iran; D016254:Mutagenesis, Insertional; D012275:Oryza / Q000382:microbiology; D018384:Oxidative Stress; D010935:Plant Diseases / Q000382:microbiology*; D013312:Stress, Physiological; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism*; D014974:Xanthomonas / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*
chemical_list: D004251:DNA Transposable Elements; D037521:Virulence Factors; D006861:Hydrogen Peroxide
keywords: Bacterial blight; Oxidative stress; Pathogenicity; Rice