Skip to main content
PMC home page
Genetics logoLink to Genetics
. 1998 Apr;148(4):1689–1700. doi: 10.1093/genetics/148.4.1689

Regulation of phosphate assimilation in Rhizobium (Sinorhizobium) meliloti.

S D Bardin 1, T M Finan 1
PMCID: PMC1460103  PMID: 9560387

Abstract

We report the isolation of phoB and phoU mutants of the bacterium Rhizobium (Sinorhizobium) meliloti. These mutants form N2-fixing nodules on the roots of alfalfa plants. R. meliloti mutants defective in the phoCDET (ndvF) encoded phosphate transport system grow slowly in media containing 2 mM Pi, and form nodules which fail to fix nitrogen (Fix-). We show that the transfer of phoB or phoU insertion mutations into phoC mutant strains restores the ability of these mutants to: (i) form normal N2-fixing root-nodules, and (ii) grow like the wild type in media containing 2 mM Pi. We also show that expression of the alternate orfA pit encoded Pi transport system is negatively regulated by the phoB gene product, whereas phoB is required for phoCDET expression. We suggest that in R. meliloti cells growing under Pi limiting conditions, PhoB protein activates phoCDET transcription and represses orfA pit transcription. Our results suggest that there are major differences between the Escherichia coli and R. meliloti phosphate regulatory systems.

Full Text

The Full Text of this article is available as a PDF (208.8 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Amemura M., Shinagawa H., Makino K., Otsuji N., Nakata A. Cloning of and complementation tests with alkaline phosphatase regulatory genes (phoS and phoT) of Escherichia coli. J Bacteriol. 1982 Nov;152(2):692–701. doi: 10.1128/jb.152.2.692-701.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Anba J., Bidaud M., Vasil M. L., Lazdunski A. Nucleotide sequence of the Pseudomonas aeruginosa phoB gene, the regulatory gene for the phosphate regulon. J Bacteriol. 1990 Aug;172(8):4685–4689. doi: 10.1128/jb.172.8.4685-4689.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bardin S., Dan S., Osteras M., Finan T. M. A phosphate transport system is required for symbiotic nitrogen fixation by Rhizobium meliloti. J Bacteriol. 1996 Aug;178(15):4540–4547. doi: 10.1128/jb.178.15.4540-4547.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Charles T. C., Finan T. M. Analysis of a 1600-kilobase Rhizobium meliloti megaplasmid using defined deletions generated in vivo. Genetics. 1991 Jan;127(1):5–20. doi: 10.1093/genetics/127.1.5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Charles T. C., Newcomb W., Finan T. M. ndvF, a novel locus located on megaplasmid pRmeSU47b (pEXO) of Rhizobium meliloti, is required for normal nodule development. J Bacteriol. 1991 Jul;173(13):3981–3992. doi: 10.1128/jb.173.13.3981-3992.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cox G. B., Webb D., Godovac-Zimmermann J., Rosenberg H. Arg-220 of the PstA protein is required for phosphate transport through the phosphate-specific transport system in Escherichia coli but not for alkaline phosphatase repression. J Bacteriol. 1988 May;170(5):2283–2286. doi: 10.1128/jb.170.5.2283-2286.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cox G. B., Webb D., Rosenberg H. Specific amino acid residues in both the PstB and PstC proteins are required for phosphate transport by the Escherichia coli Pst system. J Bacteriol. 1989 Mar;171(3):1531–1534. doi: 10.1128/jb.171.3.1531-1534.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Finan T. M., Hartweig E., LeMieux K., Bergman K., Walker G. C., Signer E. R. General transduction in Rhizobium meliloti. J Bacteriol. 1984 Jul;159(1):120–124. doi: 10.1128/jb.159.1.120-124.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Finan T. M., Kunkel B., De Vos G. F., Signer E. R. Second symbiotic megaplasmid in Rhizobium meliloti carrying exopolysaccharide and thiamine synthesis genes. J Bacteriol. 1986 Jul;167(1):66–72. doi: 10.1128/jb.167.1.66-72.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Finan T. M., Oresnik I., Bottacin A. Mutants of Rhizobium meliloti defective in succinate metabolism. J Bacteriol. 1988 Aug;170(8):3396–3403. doi: 10.1128/jb.170.8.3396-3403.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Furuichi T., Inouye M., Inouye S. Novel one-step cloning vector with a transposable element: application to the Myxococcus xanthus genome. J Bacteriol. 1985 Oct;164(1):270–275. doi: 10.1128/jb.164.1.270-275.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kato J., Sakai Y., Nikata T., Ohtake H. Cloning and characterization of a Pseudomonas aeruginosa gene involved in the negative regulation of phosphate taxis. J Bacteriol. 1994 Sep;176(18):5874–5877. doi: 10.1128/jb.176.18.5874-5877.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Klein S., Lohman K., Clover R., Walker G. C., Signer E. R. A directional, high-frequency chromosomal mobilization system for genetic mapping of Rhizobium meliloti. J Bacteriol. 1992 Jan;174(1):324–326. doi: 10.1128/jb.174.1.324-326.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Makino K., Amemura M., Kawamoto T., Kimura S., Shinagawa H., Nakata A., Suzuki M. DNA binding of PhoB and its interaction with RNA polymerase. J Mol Biol. 1996 May 31;259(1):15–26. doi: 10.1006/jmbi.1996.0298. [DOI] [PubMed] [Google Scholar]
  15. Makino K., Shinagawa H., Amemura M., Kawamoto T., Yamada M., Nakata A. Signal transduction in the phosphate regulon of Escherichia coli involves phosphotransfer between PhoR and PhoB proteins. J Mol Biol. 1989 Dec 5;210(3):551–559. doi: 10.1016/0022-2836(89)90131-9. [DOI] [PubMed] [Google Scholar]
  16. Oresnik I. J., Charles T. C., Finan T. M. Second site mutations specifically suppress the Fix- phenotype of Rhizobium meliloti ndvF mutations on alfalfa: identification of a conditional ndvF-dependent mucoid colony phenotype. Genetics. 1994 Apr;136(4):1233–1243. doi: 10.1093/genetics/136.4.1233. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Parkinson J. S. Signal transduction schemes of bacteria. Cell. 1993 Jun 4;73(5):857–871. doi: 10.1016/0092-8674(93)90267-t. [DOI] [PubMed] [Google Scholar]
  18. Ronson C. W., Nixon B. T., Ausubel F. M. Conserved domains in bacterial regulatory proteins that respond to environmental stimuli. Cell. 1987 Jun 5;49(5):579–581. doi: 10.1016/0092-8674(87)90530-7. [DOI] [PubMed] [Google Scholar]
  19. Smith M. W., Payne J. W. Expression of periplasmic binding proteins for peptide transport is subject to negative regulation by phosphate limitation in Escherichia coli. FEMS Microbiol Lett. 1992 Dec 15;100(1-3):183–190. doi: 10.1111/j.1574-6968.1992.tb14038.x. [DOI] [PubMed] [Google Scholar]
  20. Tommassen J., de Geus P., Lugtenberg B., Hackett J., Reeves P. Regulation of the pho regulon of Escherichia coli K-12. Cloning of the regulatory genes phoB and phoR and identification of their gene products. J Mol Biol. 1982 May 15;157(2):265–274. doi: 10.1016/0022-2836(82)90233-9. [DOI] [PubMed] [Google Scholar]
  21. Van Veen H. W., Abee T., Kortstee G. J., Konings W. N., Zehnder A. J. Characterization of two phosphate transport systems in Acinetobacter johnsonii 210A. J Bacteriol. 1993 Jan;175(1):200–206. doi: 10.1128/jb.175.1.200-206.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. VanBogelen R. A., Olson E. R., Wanner B. L., Neidhardt F. C. Global analysis of proteins synthesized during phosphorus restriction in Escherichia coli. J Bacteriol. 1996 Aug;178(15):4344–4366. doi: 10.1128/jb.178.15.4344-4366.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Wanner B. L. Is cross regulation by phosphorylation of two-component response regulator proteins important in bacteria? J Bacteriol. 1992 Apr;174(7):2053–2058. doi: 10.1128/jb.174.7.2053-2058.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Wanner B. L., Wilmes-Riesenberg M. R. Involvement of phosphotransacetylase, acetate kinase, and acetyl phosphate synthesis in control of the phosphate regulon in Escherichia coli. J Bacteriol. 1992 Apr;174(7):2124–2130. doi: 10.1128/jb.174.7.2124-2130.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Willsky G. R., Malamy M. H. Characterization of two genetically separable inorganic phosphate transport systems in Escherichia coli. J Bacteriol. 1980 Oct;144(1):356–365. doi: 10.1128/jb.144.1.356-365.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Willsky G. R., Malamy M. H. Control of the synthesis of alkaline phosphatase and the phosphate-binding protein in Escherichia coli. J Bacteriol. 1976 Jul;127(1):595–609. doi: 10.1128/jb.127.1.595-609.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Zhan H. J., Lee C. C., Leigh J. A. Induction of the second exopolysaccharide (EPSb) in Rhizobium meliloti SU47 by low phosphate concentrations. J Bacteriol. 1991 Nov;173(22):7391–7394. doi: 10.1128/jb.173.22.7391-7394.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. van Veen H. W., Abee T., Kortstee G. J., Konings W. N., Zehnder A. J. Mechanism and energetics of the secondary phosphate transport system of Acinetobacter johnsonii 210A. J Biol Chem. 1993 Sep 15;268(26):19377–19383. [PubMed] [Google Scholar]
  29. van Veen H. W., Abee T., Kortstee G. J., Konings W. N., Zehnder A. J. Translocation of metal phosphate via the phosphate inorganic transport system of Escherichia coli. Biochemistry. 1994 Feb 22;33(7):1766–1770. doi: 10.1021/bi00173a020. [DOI] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES