Iron depletion affects nitrogenase activity and expression of nifH and nifA genes in Herbaspirillum seropedicae.

FEMS Microbiol Lett

Laboratorio de Ecología Microbiana, Instituto de Investigaciones Biológicas Clemente Estable-MEC, Unidad Asociada a Facultad de Ciencias-UdelaR, Montevideo, Uruguay.

Published: May 2006

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.

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http://dx.doi.org/10.1111/j.1574-6968.2006.00218.xDOI Listing

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