title: Iron depletion affects nitrogenase activity and expression of nifH and nifA genes in Herbaspirillum seropedicae.
abstract: Herbaspirillum seropedicae Z67 is a nitrogen-fixing bacterium able to colonize the rhizosphere and the interior of several plants. As iron is a key element for nitrogen fixation, we examined the response of this microorganism to iron deficiency under nitrogen fixing conditions. We identified a H. seropedicae exbD gene that was induced in response to iron limitation and is involved in iron homeostasis. We found that an exbD mutant grown in iron-chelated medium is unable to fix nitrogen. Moreover, we provide evidence that expression of the nifH and nifA genes is iron dependent in a H. seropedicae genetic background.
authors.affiliation: Laboratorio de Ecología Microbiana, Instituto de Investigaciones Biológicas Clemente Estable-MEC, Unidad Asociada a Facultad de Ciencias-UdelaR, Montevideo, Uruguay.
authors.forename: Federico
authors.initials: F
authors.lastname: Rosconi
authors.forename: Emanuel M
authors.initials: EM
authors.lastname: Souza
authors.forename: Fabio O
authors.initials: FO
authors.lastname: Pedrosa
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Platero
authors.forename: Cecilia
authors.initials: C
authors.lastname: González
authors.forename: Marcela
authors.initials: M
authors.lastname: González
authors.forename: Silvia
authors.initials: S
authors.lastname: Batista
authors.forename: Paul R
authors.initials: PR
authors.lastname: Gill
authors.forename: Elena R
authors.initials: ER
authors.lastname: Fabiano
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D042803:Herbaspirillum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000235:genetics / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; C061338:NifA protein, Bacteria; D014157:Transcription Factors; D007501:Iron; D010088:Oxidoreductases; D009591:Nitrogenase; C029130:nitrogenase reductase