This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Brito, B.
Right arrow Articles by Palacios, J. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Brito, B.
Right arrow Articles by Palacios, J. M.
Agricola
Right arrow Articles by Brito, B.
Right arrow Articles by Palacios, J. M.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, March 2000, p. 937-942, Vol. 66, No. 3
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Nickel Availability and hupSL Activation by Heterologous Regulators Limit Symbiotic Expression of the Rhizobium leguminosarum bv. Viciae Hydrogenase System in Hupminus Rhizobia

Belén Brito,1 Jorge Monza,1,dagger Juan Imperial,1,2 Tomás Ruiz-Argüeso,1 and Jose Manuel Palacios1,*

Laboratorio de Microbiología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid,1 and Consejo Superior de Investigaciones Científicas,2 Ciudad Universitaria s/n, 28040 Madrid, Spain

Received 5 August 1999/Accepted 29 November 1999

A limited number of Rhizobium and Bradyrhizobium strains possess a hydrogen uptake (Hup) system that recycles the hydrogen released from the nitrogen fixation process in legume nodules. To extend this ability to rhizobia that nodulate agronomically important crops, we investigated factors that affect the expression of a cosmid-borne Hup system from Rhizobium leguminosarum bv. viciae UPM791 in R. leguminosarum bv. viciae, Rhizobium etli, Mesorhizobium loti, and Sinorhizobium meliloti Hup- strains. After cosmid pAL618 carrying the entire hup system of strain UPM791 was introduced, all recipient strains acquired the ability to oxidize H2 in symbioses with their hosts, although the levels of hydrogenase activity were found to be strain and species dependent. The levels of hydrogenase activity were correlated with the levels of nickel-dependent processing of the hydrogenase structural polypeptides and with transcription of structural genes. Expression of the NifA-dependent hupSL promoter varied depending on the genetic background, while the hyp operon, which is controlled by the FnrN transcriptional regulator, was expressed at similar levels in all recipient strains. With the exception of the R. etli-bean symbiosis, the availability of nickel to bacteroids strongly affected hydrogenase processing and activity in the systems tested. Our results indicate that efficient transcriptional activation by heterologous regulators and processing of the hydrogenase as a function of the availability of nickel to the bacteroid are relevant factors that affect hydrogenase expression in heterologous rhizobia.

* Corresponding author. Mailing address: Laboratorio de Microbiología, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain. Phone: 34-91-3365753. Fax: 34-91-3365757. E-mail: jpalacios{at}bit.etsia.upm.es.

dagger Present address: Departamento de Bioquímica, Facultad de Agronomía, Universidad de la República, CP 11600 Montevideo, Uruguay.

Applied and Environmental Microbiology, March 2000, p. 937-942, Vol. 66, No. 3
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Baginsky, C., Brito, B., Imperial, J., Ruiz-Argueso, T., Palacios, J. M. (2005). Symbiotic Hydrogenase Activity in Bradyrhizobium sp. (Vigna) Increases Nitrogen Content in Vigna unguiculata Plants. Appl. Environ. Microbiol. 71: 7536-7538 [Abstract] [Full Text]  
  • Ureta, A.-C., Imperial, J., Ruiz-Argueso, T., Palacios, J. M. (2005). Rhizobium leguminosarum Biovar viciae Symbiotic Hydrogenase Activity and Processing Are Limited by the Level of Nickel in Agricultural Soils. Appl. Environ. Microbiol. 71: 7603-7606 [Abstract] [Full Text]  
  • Baginsky, C., Brito, B., Imperial, J., Palacios, J.-M., Ruiz-Argueso, T. (2002). Diversity and Evolution of Hydrogenase Systems in Rhizobia. Appl. Environ. Microbiol. 68: 4915-4924 [Abstract] [Full Text]  
  • Brito, B., Palacios, J. M., Imperial, J., Ruiz-Argueso, T. (2002). Engineering the Rhizobium leguminosarum bv. viciae Hydrogenase System for Expression in Free-Living Microaerobic Cells and Increased Symbiotic Hydrogenase Activity. Appl. Environ. Microbiol. 68: 2461-2467 [Abstract] [Full Text]  
  • Báscones, E., Imperial, J., Ruiz-Argüeso, T., Palacios, J. M. (2000). Generation of New Hydrogen-Recycling Rhizobiaceae Strains by Introduction of a Novel hup Minitransposon. Appl. Environ. Microbiol. 66: 4292-4299 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»