title: An oxidative burst and its attenuation by bacterial peroxidase activity is required for optimal establishment of the Arachis hypogaea-Bradyrhizobium sp. symbiosis.
abstract: OBJECTIVE
  The main purpose of this study was to determine whether the Arachis hypogaea L. root oxidative burst, produced at early stages of its symbiotic interaction with Bradyrhizobium sp. SEMIA 6144, and the bacterial antioxidant system are required for the successful development of this interaction.
  
  
  RESULTS
  Pharmacological approaches were used to reduce both plant oxidative burst and bacterial peroxidase enzyme activity. In plants whose H2 O2 levels were decreased, a low nodule number, a reduction in the proportion of red nodules (%) and an increase in the bacteroid density were found. The symbiotic phenotype of plants inoculated with a Bradyrhizobium sp. SEMIA 6144 culture showing decreased peroxidase activity was also affected, since the biomass production, nodule number and percentage of red nodules in these plants were lower than in plants inoculated with Bradyrhizobium sp. control cultures.
  
  
  CONCLUSIONS
  We demonstrated for the first time that the oxidative burst triggered at the early events of the symbiotic interaction in peanut, is a prerequisite for the efficient development of root nodules, and that the antioxidant system of bradyrhizobial peanut symbionts, particularly the activity of peroxidases, is counteracting this oxidative burst for the successful establishment of the symbiosis.
  
  
  CONCLUSIONS
  Our results provide new insights into the mechanisms involved in the development of the symbiotic interaction established in A. hypogaea L. a legume infected in an intercellular way.
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
authors.forename: V
authors.identifier: http://orcid.org/0000-0003-2593-3109
authors.initials: V
authors.lastname: Muñoz
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
authors.forename: F
authors.initials: F
authors.lastname: Ibáñez
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
authors.forename: M S
authors.initials: MS
authors.lastname: Figueredo
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Fabra
mesh_terms: D010367:Arachis / Q000235:genetics / Q000382:microbiology* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020369:Bradyrhizobium / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000382:microbiology / Q000502:physiology; D016897:Respiratory Burst; D053204:Root Nodules, Plant / Q000382:microbiology; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D010544:Peroxidases
keywords: Arachis hypogaea L.; Bradyrhizobium sp.; antioxidant system; hydrogen peroxide; oxidative burst; symbiosis