Preferences help
enabled [disable] Abstract
Number of results
2001 | 48 | 2 | 359-365
Article title

nod Genes and Nod signals and the evolution of the rhizobium legume symbiosis.

Title variants
Languages of publication
The establishment of the nitrogen-fixing symbiosis between rhizobia and legumes requires an exchange of signals between the two partners. In response to flavonoids excreted by the host plant, rhizobia synthesize Nod factors (NFs) which elicit, at very low concentrations and in a specific manner, various symbiotic responses on the roots of the legume hosts. NFs from several rhizobial species have been characterized. They all are lipo-chitooligosaccharides, consisting of a backbone of generally four or five glucosamine residues N-acylated at the non-reducing end, and carrying various O-substituents. The N-acyl chain and the other substituents are important determinants of the rhizobial host specificity. A number of nodulation genes which specify the synthesis of NFs have been identified. All rhizobia, in spite of their diversity, possess conserved nodABC genes responsible for the synthesis of the N-acylated oligosaccharide core of NFs, which suggests that these genes are of a monophyletic origin. Other genes, the host specific nod genes, specify the substitutions of NFs. The central role of NFs and nod genes in the Rhizobium-legume symbiosis suggests that these factors could be used as molecular markers to study the evolution of this symbiosis. We have studied a number of NFs which are N-acylated by α,β-unsaturated fatty acids. We found that the ability to synthesize such NFs does not correlate with taxonomic position of the rhizobia. However, all rhizobia that produce NFs such nodulate plants belonging to related tribes of legumes, the Trifolieae, Vicieae, and Galegeae, all of them being members of the so-called galegoid group. This suggests that the ability to recognize the NFs with α,β-unsaturated fatty acids is limited to this group of legumes, and thus might have appeared only once in the course of legume evolution, in the galegoid phylum.

Physical description
  • LBMRPM INRA-CNRS, BP27 31326 Castanet Tolosan Cedex, France
  • LSTM-IRD, BP5035 34032 Montpellier Cedex, France
  • BIA-INRA, BP27 31326 Castanet Tolosan Cedex, France
  • LBMRPM INRA-CNRS, BP27 31326 Castanet Tolosan Cedex, France
  • LSTM-IRD, BP5035 34032 Montpellier Cedex, France
  • Debellé, F., Plazanet, C., Roche, P., Pujol, C., Savagnac, A., Rosenberg, C., Promé, J.C. & Dénarié, J. (1996) The NodA proteins of Rhizobium meliloti and Rhizobium tropici specify the N-acylation of Nod factors by different fatty acids. Mol. Microbiol. 22, 303-314.
  • Dénarié, J., Debellé, F. & Promé, J.C. (1996) Rhizobium lipo-chitooligosaccharide nodulation factors: Signaling molecules mediating recognition and morphogenesis. Annu. Rev. Biochem. 65, 503-535.
  • Downie, J.A. (1998) Functions of rhizobial nodulation genes; in The Rhizobiaceae (Spaink, H.P., Kondorosi, A. & Hooykaas, P.J.J., eds.) pp. 387-402.
  • Doyle, J.J. (1998) Phylogenetic perspectives on nodulation: Evolving views of plants and symbiotic bacteria. Trends Plant Sci. 3, 473-478.
  • Krishnan, H.B., Lewin, A., Fellay, R., Broughton, W.J. & Pueppke, S.G. (1992) Differential expression of nodS accounts for the varied abilities of Rhizobium fredii USDA257 and Rhizobium sp. strain NGR234 to nodulate Leucaena spp. Mol. Microbiol. 6, 3321-3330.
  • Lorquin, J., Lortet, G., Ferro, M., Méar, N., Dreyfus, B., Promé, J.C. & Boivin, C. (1997) Nod factors from Sinorhizobium saheli and S. teranga bv. sesbaniae are both arabinosylated and fucosylated, a structural feature specific to Sesbania rostrata symbionts. Mol. Plant-Microbe Interact. 10, 879-890.
  • Perret, X., Staehelin, C. & Broughton, W.J. (2000) Molecular basis of symbiotic promiscuity. Microbiol. Mol. Biol. Rev. 64, 180-201.
  • Ritsema, T., Wijfjes, A.H.M., Lugtenberg, B.J.J. & Spaink, H.P. (1996) Rhizobium nodulation protein NodA is a host-specific determinant of the transfer of fatty acids in Nod factor biosynthesis. Mol. Gen. Genet. 251, 44-51.
  • Roche, P., Debellé, F., Maillet, F., Lerouge, P., Faucher, C., Truchet, G., Dénarié, J. & Promé, J.C. (1991) Molecular basis of symbiotic host specificity in Rhizobium meliloti: nodH and nodPQ genes encode the sulfation of lipo-oligosaccharide signals. Cell 67, 1131-1143.
  • Turner S.L. & Young, J.P. (2000) The glutamine synthetases of rhizobia: Phylogenetics and evolutionary implications. Mol. Biol. Evol. 17, 309-319.
  • Yang, G.P., Debellé, F., Savagnac, A., Ferro, M., Schiltz, O., Maillet, F., Promé, D., Treilhou, M., Vialas, C., Lindstrom, K., Dénarié, J. & Promé, J.C. (1999) Structure of the Mesorhizobium huakuii and Rhizobium galegae Nod factors: A cluster of phylogenetically related legumes are nodulated by rhizobia producing α,β-unsaturated fatty acids. Mol. Microbiol. 34, 227-237.
Document Type
Publication order reference
YADDA identifier
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.