Rhizobium nodM and nodN genes are common nod genes

nodM encodes functions for efficiency of nod signal production and bacteroid maturation

N. Baev, M. Schultze, I. Barlier, Cam Ha Dang Cam Ha, H. Virelizier, É. Kondorosi, A. Kondorosi

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Earlier, we showed that Rhizobium meliloti nodM codes for glucosamine synthase and that nodM and nodN mutants produce strongly reduced root hair deformation activity and display delayed nodulation of Medicago sativa (Baev et al., Mol. Gen. Genet. 228:113-124, 1991). Here, we demonstrate that nodM and nodN genes from Rhizobium leguminosarum biovar viciae restore the root hair deformation activity of exudates of the corresponding R. meliloti mutant strains. Partial restoration of the nodulation phenotypes of these two strains was also observed. In nodulation assays, galactosamine and N- acetylglucosamine could substitute for glucosamine in the suppression of the R. meliloti nodM mutation, although N-acetylglucosamine was less efficient. We observed that in nodules induced by nodM mutants, the bacteroids did not show complete development or were deteriorated, resulting in decreased nitrogen fixation and, consequently, lower dry weights of the plants. This mutant phenotype could also be suppressed by exogenously supplied glucosamine, N-acetylglucosamine, and galactosamine and to a lesser extent by glucosamine-6-phosphate, indicating that the nodM mutant bacteroids are limited for glucosamine. In addition, by using derivatives of the wild type and a nodM mutant in which the nod genes are expressed at a high constitutive level, it was shown that the nodM mutant produces significantly fewer Nod factors than the wild-type strain but that their chemical structures are unchanged. However, the relative amounts of analogs of the cognate Nod signals were elevated, and this may explain the observed host range effects of the nodM mutation. Our data indicate that both the nodM and nodN genes of the two species have common functions and confirm that NodM is a glucosamine synthase with the biochemical role of providing sufficient amounts of the sugar moiety for the synthesis of the glucosamine oligosaccharide signal molecules.

Original languageEnglish
Pages (from-to)7555-7565
Number of pages11
JournalJournal of Bacteriology
Volume174
Issue number23
Publication statusPublished - 1992

Fingerprint

Rhizobium
Glucosamine
Sinorhizobium meliloti
Acetylglucosamine
Genes
Galactosamine
Rhizobium leguminosarum
Viverridae
Phenotype
Nitrogen Fixation
Mutation
Medicago sativa
Host Specificity
Exudates and Transudates
Oligosaccharides
Weights and Measures

ASJC Scopus subject areas

  • Applied Microbiology and Biotechnology
  • Immunology

Cite this

Baev, N., Schultze, M., Barlier, I., Dang Cam Ha, C. H., Virelizier, H., Kondorosi, É., & Kondorosi, A. (1992). Rhizobium nodM and nodN genes are common nod genes: nodM encodes functions for efficiency of nod signal production and bacteroid maturation. Journal of Bacteriology, 174(23), 7555-7565.

Rhizobium nodM and nodN genes are common nod genes : nodM encodes functions for efficiency of nod signal production and bacteroid maturation. / Baev, N.; Schultze, M.; Barlier, I.; Dang Cam Ha, Cam Ha; Virelizier, H.; Kondorosi, É.; Kondorosi, A.

In: Journal of Bacteriology, Vol. 174, No. 23, 1992, p. 7555-7565.

Research output: Contribution to journalArticle

Baev, N, Schultze, M, Barlier, I, Dang Cam Ha, CH, Virelizier, H, Kondorosi, É & Kondorosi, A 1992, 'Rhizobium nodM and nodN genes are common nod genes: nodM encodes functions for efficiency of nod signal production and bacteroid maturation', Journal of Bacteriology, vol. 174, no. 23, pp. 7555-7565.
Baev, N. ; Schultze, M. ; Barlier, I. ; Dang Cam Ha, Cam Ha ; Virelizier, H. ; Kondorosi, É. ; Kondorosi, A. / Rhizobium nodM and nodN genes are common nod genes : nodM encodes functions for efficiency of nod signal production and bacteroid maturation. In: Journal of Bacteriology. 1992 ; Vol. 174, No. 23. pp. 7555-7565.
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abstract = "Earlier, we showed that Rhizobium meliloti nodM codes for glucosamine synthase and that nodM and nodN mutants produce strongly reduced root hair deformation activity and display delayed nodulation of Medicago sativa (Baev et al., Mol. Gen. Genet. 228:113-124, 1991). Here, we demonstrate that nodM and nodN genes from Rhizobium leguminosarum biovar viciae restore the root hair deformation activity of exudates of the corresponding R. meliloti mutant strains. Partial restoration of the nodulation phenotypes of these two strains was also observed. In nodulation assays, galactosamine and N- acetylglucosamine could substitute for glucosamine in the suppression of the R. meliloti nodM mutation, although N-acetylglucosamine was less efficient. We observed that in nodules induced by nodM mutants, the bacteroids did not show complete development or were deteriorated, resulting in decreased nitrogen fixation and, consequently, lower dry weights of the plants. This mutant phenotype could also be suppressed by exogenously supplied glucosamine, N-acetylglucosamine, and galactosamine and to a lesser extent by glucosamine-6-phosphate, indicating that the nodM mutant bacteroids are limited for glucosamine. In addition, by using derivatives of the wild type and a nodM mutant in which the nod genes are expressed at a high constitutive level, it was shown that the nodM mutant produces significantly fewer Nod factors than the wild-type strain but that their chemical structures are unchanged. However, the relative amounts of analogs of the cognate Nod signals were elevated, and this may explain the observed host range effects of the nodM mutation. Our data indicate that both the nodM and nodN genes of the two species have common functions and confirm that NodM is a glucosamine synthase with the biochemical role of providing sufficient amounts of the sugar moiety for the synthesis of the glucosamine oligosaccharide signal molecules.",
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T2 - nodM encodes functions for efficiency of nod signal production and bacteroid maturation

AU - Baev, N.

AU - Schultze, M.

AU - Barlier, I.

AU - Dang Cam Ha, Cam Ha

AU - Virelizier, H.

AU - Kondorosi, É.

AU - Kondorosi, A.

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N2 - Earlier, we showed that Rhizobium meliloti nodM codes for glucosamine synthase and that nodM and nodN mutants produce strongly reduced root hair deformation activity and display delayed nodulation of Medicago sativa (Baev et al., Mol. Gen. Genet. 228:113-124, 1991). Here, we demonstrate that nodM and nodN genes from Rhizobium leguminosarum biovar viciae restore the root hair deformation activity of exudates of the corresponding R. meliloti mutant strains. Partial restoration of the nodulation phenotypes of these two strains was also observed. In nodulation assays, galactosamine and N- acetylglucosamine could substitute for glucosamine in the suppression of the R. meliloti nodM mutation, although N-acetylglucosamine was less efficient. We observed that in nodules induced by nodM mutants, the bacteroids did not show complete development or were deteriorated, resulting in decreased nitrogen fixation and, consequently, lower dry weights of the plants. This mutant phenotype could also be suppressed by exogenously supplied glucosamine, N-acetylglucosamine, and galactosamine and to a lesser extent by glucosamine-6-phosphate, indicating that the nodM mutant bacteroids are limited for glucosamine. In addition, by using derivatives of the wild type and a nodM mutant in which the nod genes are expressed at a high constitutive level, it was shown that the nodM mutant produces significantly fewer Nod factors than the wild-type strain but that their chemical structures are unchanged. However, the relative amounts of analogs of the cognate Nod signals were elevated, and this may explain the observed host range effects of the nodM mutation. Our data indicate that both the nodM and nodN genes of the two species have common functions and confirm that NodM is a glucosamine synthase with the biochemical role of providing sufficient amounts of the sugar moiety for the synthesis of the glucosamine oligosaccharide signal molecules.

AB - Earlier, we showed that Rhizobium meliloti nodM codes for glucosamine synthase and that nodM and nodN mutants produce strongly reduced root hair deformation activity and display delayed nodulation of Medicago sativa (Baev et al., Mol. Gen. Genet. 228:113-124, 1991). Here, we demonstrate that nodM and nodN genes from Rhizobium leguminosarum biovar viciae restore the root hair deformation activity of exudates of the corresponding R. meliloti mutant strains. Partial restoration of the nodulation phenotypes of these two strains was also observed. In nodulation assays, galactosamine and N- acetylglucosamine could substitute for glucosamine in the suppression of the R. meliloti nodM mutation, although N-acetylglucosamine was less efficient. We observed that in nodules induced by nodM mutants, the bacteroids did not show complete development or were deteriorated, resulting in decreased nitrogen fixation and, consequently, lower dry weights of the plants. This mutant phenotype could also be suppressed by exogenously supplied glucosamine, N-acetylglucosamine, and galactosamine and to a lesser extent by glucosamine-6-phosphate, indicating that the nodM mutant bacteroids are limited for glucosamine. In addition, by using derivatives of the wild type and a nodM mutant in which the nod genes are expressed at a high constitutive level, it was shown that the nodM mutant produces significantly fewer Nod factors than the wild-type strain but that their chemical structures are unchanged. However, the relative amounts of analogs of the cognate Nod signals were elevated, and this may explain the observed host range effects of the nodM mutation. Our data indicate that both the nodM and nodN genes of the two species have common functions and confirm that NodM is a glucosamine synthase with the biochemical role of providing sufficient amounts of the sugar moiety for the synthesis of the glucosamine oligosaccharide signal molecules.

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