Advertisement

The Journal of Microbiology

, Volume 46, Issue 2, pp 137–145 | Cite as

The GntR-type regulators GtrA and GtrB affect cell growth and nodulation of Sinorhizobium meliloti

  • Yi Wang
  • Ai-Min Chen
  • Ai-Yuan Yu
  • Li Luo
  • Guan-Qian Yu
  • Jia-Bi Zhu
  • Yan-Zhang WangEmail author
Articles

Abstract

GntR-type transcriptional regulators are involved in the regulation of various biological processes in bacteria, but little is known about their functions in Sinorhizobium meliloti. Here, we identified two GntR-type transcriptional regulator genes, gtrA and gtrB, from S. meliloti strain 1021. Both the gtrA1 mutant and the gtrB1 mutant had lower growth rates and maximal cell yields on rich and minimal media, as well as lower cell motility on swimming plates, than did the wild-type strain. Both mutants were also symbiotically deficient. Alfalfa plants inoculated with wild-type strain 1021 formed pink elongated nodules on primary roots. In contrast, the plants inoculated with the gtrA1 and gtrB1 mutants formed relatively smaller, round, light pink nodules mainly on lateral roots. During the first 3∼4 weeks post-inoculation, the plants inoculated with the gtrA1 and gtrB1 mutants were apparently stunted, with lower levels of nitrogenase activity, but there was a remarkable increase in the number of nodules compared to those inoculated with the wild-type strain. Moreover, the gtrA1 and gtrB1 mutants not only showed delayed nodulation, but also showed markedly reduced nodulation competition. These results demonstrated that both GtrA and GtrB affect cell growth and effective symbiosis of S. meliloti. Our work provides new insight into the functions of GntR-like transcriptional regulators.

Keywords

GntR-type transcriptional regulators GtrA GtrB cell growth nodulation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Ames, P., S.A. Schluederberg, and K. Bergman. 1980. Behavioral mutants of Rhizobium meliloti. J. Bacteriol. 141, 722–727.PubMedGoogle Scholar
  2. An, J.H. and Y.S. Kim. 1998. A gene cluster encoding malonyl-CoA decarboxylase (MatA), malonyl-CoA synthetase (MatB) and a putative dicarboxylate carrier protein (MatC) in Rhizobium trifolii-cloning, sequencing, and expression of the enzymes in Escherichia coli. Eur. J. Biochem. 257, 395–402.PubMedCrossRefGoogle Scholar
  3. An, J.H., H.Y. Lee, K.N. Ko, E.S. Kim, and Y.S. Kim. 2002. Symbiotic effects of ΔmatB Rhizobium leguminosarum bv. trifolii mutant on clovers. Mol. Cells 14, 261–266.PubMedGoogle Scholar
  4. Casali, N., A.M. White, and L.W. Riley. 2006. Regulation of the Mycobacterium tuberculosis mce1 operon. J. Bacteriol. 188, 441–449.PubMedCrossRefGoogle Scholar
  5. Denarie, J., F. Debelle, and J.C. Prome. 1996. Rhizobium lipo-chitooligosaccharide nodulation factors: signaling molecules mediating recognition and morphogenesis. Annu. Rev. Biochem. 65, 503–535.PubMedCrossRefGoogle Scholar
  6. Fujita, Y. and T. Fujita. 1987. The gluconate operon gnt of Bacillus subtilis encodes its own transcriptional negative regulator. Proc. Natl. Acad. Sci. USA 84, 4524–4528.PubMedCrossRefGoogle Scholar
  7. Galibert, F., T.M. Finan, S.R. Long, A. Puhler, P. Abola, F. Ampe, F. Barloy-Hubler, M.J. Barnett, A. Becker, P. Boistard, G. Bothe, M. Boutry, L. Bowser, J. Buhrmester, E. Cadieu, D. Capela, P. Chain, A. Cowie, R.W. Davis, S. Dreano, et al. 2001. The composite genome of the legume symbiont Sinorhizobium meliloti. Science 293, 668–672.PubMedCrossRefGoogle Scholar
  8. Haine, V., A. Sinon, F. Van Steen, S. Rousseau, M. Dozot, P. Lestrate, C. Lambert, J.J. Letesson, and X. De Bolle. 2005. Systematic targeted mutagenesis of Brucella melitensis 16M reveals a major role for GntR regulators in the control of virulence. Infect. Immun. 73, 5578–5586.PubMedCrossRefGoogle Scholar
  9. Haydon, D.J. and J.R. Guest. 1991. A new family of bacterial regulatory proteins. FEMS Microbiol. Lett. 79, 291–296.CrossRefGoogle Scholar
  10. Hillerich, B. and J. Westpheling. 2006. A new GntR family transcriptional regulator in Streptomyces coelicolor is required for morphogenesis and antibiotic production and controls transcription of an ABC transporter in response to carbon source. J. Bacteriol. 188, 7477–7487.PubMedCrossRefGoogle Scholar
  11. Honma, M.A. and F.M. Ausubel. 1987. Rhizobium meliloti has three functional copies of the nodD symbiotic regulatory gene. Proc. Natl. Acad. Sci. USA 84, 8558–8562.PubMedCrossRefGoogle Scholar
  12. Hoskisson, P.A., S. Rigali, K. Fowler, K.C. Findlay, and M.J. Buttner. 2006. DevA, a GntR-like transcriptional regulator required for development in Streptomyces coelicolor. J. Bacteriol. 188, 5014–5023.PubMedCrossRefGoogle Scholar
  13. Kondorosi, E., M. Pierre, M. Cren, U. Haumann, M. Buire, B. Hoffmann, J. Schell, and A. Kondorosi. 1991. Identification of NolR, a negative transacting factor controlling the nod regulon in Rhizobium meliloti. J. Mol. Biol. 222, 885–896.PubMedCrossRefGoogle Scholar
  14. Lee, H.Y., J.H. An, and Y.S. Kim. 2000. Identification and characterization of a novel transcriptional regulator, MatR, for malonate metabolism in Rhizobium leguminosarum bv. trifolii. Eur. J. Biochem. 267, 7224–7230.PubMedCrossRefGoogle Scholar
  15. Lee, M.H., M. Scherer, S. Rigali, and J.W. Golden. 2003. PlmA, a new member of the GntR family, has plasmid maintenance functions in Anabaena sp. strain PCC 7120. J. Bacteriol. 85, 4315–4325.CrossRefGoogle Scholar
  16. Leigh, J.A., E.R. Signer, and G.C. Walker. 1985. Exopolysaccharide deficient mutants of Rhizobium meliloti that form ineffective nodules. Proc. Natl. Acad. Sci. USA 82, 6231–6235.PubMedCrossRefGoogle Scholar
  17. Long, S.R. 1996. Rhizobium symbiosis: Nod factors in perspective. Plant Cell. 8, 1885–1898.PubMedCrossRefGoogle Scholar
  18. Long, S., J.W. Reed, J. Himawan, and G.C. Walker. 1988. Genetic analysis of a cluster of genes required for synthesis of the calcofluor-binding exopolysaccharide of Rhizobium meliloti. J. Bacteriol. 170, 4239–4248.PubMedGoogle Scholar
  19. Luo, L., S.Y. Yao, A. Becker, S. Ruberg, G.O. Yu, J.B. Zhu, and H.P. Cheng. 2005. Two new Sinorhizobium meliloti LysR-type transcriptional regulators required for nodulation. J. Bacteriol. 187, 4562–4572.PubMedCrossRefGoogle Scholar
  20. Mota, L.J., P. Tavares, and I. Sa-Nogueira. 1999. Mode of action of AraR, the key regulator of L-arabinose metabolism in Bacillus subtilis. Mol. Microbiol. 33, 476–489.PubMedCrossRefGoogle Scholar
  21. Mulligan, J.T. and S.R. Long. 1989. A family of activator genes regulates expression of Rhizobium meliloti nodulation genes. Genetics 122, 7–18.PubMedGoogle Scholar
  22. Rigali, S., A. Derouaux, F. Giannotta, and J. Dusart. 2001. Subdivision of the helix-turn-helix GntR family of bacterial regulators in the FadR, HutC, MocR, and YtrA subfamilies. J. Biol. Chem. 277, 12507–12515.PubMedCrossRefGoogle Scholar
  23. Rigali, S., H. Nothaft, E.E. Noens, M. Schlicht, S. Colson, M. Muller, B. Joris, H.K. Koerten, D.A. Hopwood, F. Titgemeyer, and G.P. Van Wezel. 2006. The sugar phosphotransferase system of Streptomyces coelicolor is regulated by the GntR-family regulator DasR and links N-acetylglucosamine metabolism to the control of development. Mol. Microbiol. 61, 1237–1251.PubMedCrossRefGoogle Scholar
  24. Sa-Nogueira, I. and L.J. Mota. 1997. Negative regulation of L-arabinose metabolism in Bacillus subtilis: characterization of the araR (araC) gene. J. Bacteriol. 179, 1598–1608.PubMedGoogle Scholar
  25. Stanier, R.Y., J.L. Ingraham, M.L. Wheelis, and P.R. Painter. 1986. The Microbial World, 5th ed. Prentice-Hall, Englewood Cliffs, N.J., USA.Google Scholar
  26. Swanson, J.A., J.T. Mulligan, and S.R. Long. 1993. Regulation of syrM and nodD3 in Rhizobium meliloti. Genetics 134, 435–444.PubMedGoogle Scholar
  27. Vincent, J.M. 1970. A manual for the practical study of root-nodule bacteria. IBP handbook. No. 75. Blackwells, Oxford, England.Google Scholar
  28. Wang, S.P., J.B. Zhu, G.Q. Yu, Y.F. Wu, and S.J. Shen. 1991. Studies on heterologous expression of Rhizobium meliloti nifA gene and oxygen sensitivity of its product. Sci. China Ser. B. 34, 71–77.Google Scholar
  29. Yoshida, K.I., Y. Fujita, and S.D. Ehrlich. 2000. An operon for a putative ATP-binding cassette transport system involved in acetoin utilization of Bacillus subtilis. J. Bacteriol. 182, 5454–5461.PubMedCrossRefGoogle Scholar
  30. Zevenhuizen, L.P.T.M. and A.R.W. Van Neerven. 1993. (1,2)-β-D-glucan and acidic oligsaccharides produced by Rhizobium meliloti. Carbohydr. Res. 118, 127–134.CrossRefGoogle Scholar

Copyright information

© The Microbiological Society of Korea and Springer-Verlag Berlin Heidelber GmbH 2008

Authors and Affiliations

  • Yi Wang
    • 1
  • Ai-Min Chen
    • 1
  • Ai-Yuan Yu
    • 1
  • Li Luo
    • 2
  • Guan-Qian Yu
    • 1
  • Jia-Bi Zhu
    • 1
  • Yan-Zhang Wang
    • 1
    Email author
  1. 1.National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences (SIBS)Chinese Academy of SciencesShanghaiP. R. China
  2. 2.Biological Sciences Department, Lehman CollegeThe City University of New YorkNew YorkUSA

Personalised recommendations