C. Of, We thank Alan Prescott and Sam Swift for assistance with confocal microscopy, and Pete Rowell for use of his gas chromatograph. We also thank Bill Broughton, Lionel Moulin and Herman Spaink for bacterial strains

O. N. Allen and E. K. Allen, The Leguminosae. A source book of characteristics, uses and nodulation, 1981.

C. F. Barrett and M. A. Parker, Prevalence of Burkholderia sp. nodule symbionts on four mimosoid legumes from Barro Colorado Island, Panama. Systematic and Applied Microbiology, vol.28, pp.57-65, 2005.

C. F. Barrett and M. A. Parker, Coexistence of Burkholderia, Cupriavidus, and Rhizobium sp. nodule bacteria on two Mimosa spp. in Costa Rica, Applied and Environmental Microbiology, vol.72, pp.1198-1206, 2006.

C. M. Boone, M. Olsthoorn, F. D. Dakora, H. P. Spaink, and J. E. Thomas-oates, Structural characterisation of lipo-chitin oligosaccharides isolated from Bradyrhizobium aspalati, microsymbionts of commercially important South African legumes, Carbohydrates Research, vol.317, pp.155-163, 1999.

W. Chen, S. Laevens, T. M. Lee, T. Coenye, P. De-vos et al., Ralstonia taiwanensis sp. nov., isolated from root nodules of Mimosa species and sputum of a cystic fibrosis patient, International Journal of Systematic and Evolutionary Microbiology, vol.51, pp.1729-1735, 2001.

W. Chen, L. Moulin, C. Bontemps, P. Vandamme, G. Béna et al., Legume symbiotic nitrogen fixation by b-Proteobacteria is widespread in nature, Journal of Bacteriology, vol.185, pp.7266-7272, 2003.

W. Chen, E. K. James, A. R. Prescott, M. Kierans, and J. I. Sprent, Nodulation of Mimosa spp. by the b-proteobacterium Ralstonia taiwanensis, Molecular Plant-Microbe Interactions, vol.16, pp.1051-1061, 2003.
URL : https://hal.archives-ouvertes.fr/hal-01655708

W. Chen, S. M. De-faria, R. Straliotto, R. M. Pitard, J. L. Simões-araùjo et al., Proof that Burkholderia forms effective symbioses with legumes: a study of novel Mimosa-nodulating strains from South America, Applied and Environmental Microbiology, vol.71, pp.7461-7471, 2005.

W. Chen, E. K. James, J. Chou, S. Sheu, Y. Sprent et al., Beta-rhizobia from Mimosa pigra, a newly-discovered invasive plant in Taiwan, New Phytologist, vol.168, pp.661-675, 2005.

W. Chen, E. K. James, T. Coenye, J. Chou, E. Barrios et al., Burkholderia mimosarum sp. nov., isolated from root nodules of Mimosa spp. from Taiwan and South America, International Journal of Systematic and Evolutionary Microbiology, vol.56, pp.1847-1851, 2006.

W. Chen, S. M. De-faria, E. K. James, G. N. Elliott, K. Lin et al., Burkholderia nodosa sp. nov., isolated from root nodules of the woody Brazilian legumes Mimosa bimucronata and Mimosa scabrella, International Journal of Systematic and Evolutionary Microbiology, vol.57, pp.1055-1059, 2007.

M. P. Cocks and W. D. Stock, Field patterns of nodulation in fifteen Aspalathus species and their ecological role in the fynbos vegetation of southern Africa, Basic Applied Ecology, vol.2, pp.115-125, 2001.

F. D. Dakora, Nodulation specificity of Aspalathus linearis subsp. linearis, a shrub tea legume indigenous to the Western Cape, pp.671-672, 1998.

C. C. Deschodt and B. W. Strijdom, Effective nodulation of Aspalathus linearis by rhizobia from other Aspalathus species, Phytophylactica, vol.8, pp.103-104, 1976.

G. N. Elliott, W. Chen, J. Chou, H. Wang, S. Sheu et al., Burkholderia phymatum is a highly effective nitrogen-fixing symbiont of Mimosa spp. and fixes nitrogen ex planta, New Phytologist, vol.173, pp.168-180, 2007.

L. Estrada-de, P. Santos, R. Bustillos-cristales, and J. Caballero-mellado, Burkholderia, a genus rich in plant-associated nitrogen fixers with wide environmental and geographic distribution, Applied and Environmental Microbiology, vol.67, pp.2790-2798, 2001.

M. Gillis, T. Van, V. Bardin, R. Goor, M. Hebbar et al., Polyphasic taxonomy in the genus Burkholderia leading to an emended description of the genus and proposition of Burkholderia vietnamiensis sp. nov. for N 2 -fixing isolates from rice in Vietnam, International Journal of Systematic Bacteriology, vol.45, pp.274-289, 1995.

M. Kock, Diversity of root nodule bacteria associated with Cyclopia species, 2004.

M. Kock and P. L. Steyn, Determination of the diversity of rootnodulating bacteria associated with Cyclopia spp, Proceedings of the 6th European Nitrogen Fixation Conference, 2004.

L. Moulin, A. Munive, B. Dreyfus, and C. Boivin-masson, Nodulation of legumes by members of the b-subclass of Proteobacteria, Nature, vol.411, pp.948-950, 2001.

M. L. Muofhe and F. D. Dakora, Bradyrhizobium species isolated from indigenous legumes of the Western Cape exhibit high tolerance of low pH, p.519, 1998.

M. L. Muofhe and F. D. Dakora, Nitrogen nutrition in nodulated field plants of the shrub tea legume Aspalathus linearis assessed using 15 N natural abundance, Plant and Soil, vol.209, pp.181-186, 1999.

L. Perin, L. Martínez-aguilar, R. Castro-gonzález, P. Estrada-de-los-santos, T. Cabellos-avelar et al., Diazotrophic Burkholderia species associated with field-grown maize and sugarcane, Applied and Environmental Microbiology, vol.72, pp.3103-3110, 2006.
DOI : 10.1128/aem.72.5.3103-3110.2006

URL : https://aem.asm.org/content/72/5/3103.full.pdf

S. G. Pueppke and W. J. Broughton, Rhizobium sp. strain NGR234 and R. fredii USDA257 share exceptionally broad, nested host ranges, Molecular Plant-Microbe Interactions, vol.12, pp.293-318, 1999.

R. Rasolomampianina, X. Bailly, R. Fetiarison, R. Rabevohitra, G. Béna et al., Nitrogen-fixing nodules from rose wood legume trees (Dalbergia spp.) endemic to Madagascar host seven different genera belonging to a-and b-Proteobacteria, Molecular Ecology, vol.14, pp.4135-4146, 2005.

V. M. Reis, P. Estrada-de-los-santos, S. Tenorio-salgado, J. Vogel, M. Stoffels et al., Burkholderia tropica sp. nov., a novel nitrogenfixing, plant-associated bacterium, International Journal of Systematic and Evolutionary Microbiology, vol.54, pp.2155-2162, 2004.

P. Somasegaran and H. J. Hoben, Handbook for rhizobia: methods in legume-rhizobium technology, 1994.

J. I. Sprent, Nodulation in legumes. Kew: Royal Botanic Gardens, 2001.

J. I. Sprent, Evolving ideas of legume evolution and diversity: a taxonomic perspective on the occurrence of nodulation, New Phytologist, vol.174, pp.11-25, 2007.

J. I. Sprent and E. K. James, Legume evolution: where do nodules and mycorrhizas fit in?, Plant Physiology, vol.144, pp.575-581, 2007.

A. C. Spriggs and F. D. Dakora, Competitive ability of selected Cyclopia Vent. rhizobia under glasshouse and field conditions, Soil Biology Biochemistry, vol.39, pp.58-67, 2007.

A. C. Spriggs, W. D. Stock, and F. D. Dakora, Influence of mycorrhizal associations on foliar d 15 N values of legume and non-legume shrubs and trees in the fynbos of South Africa: implications for estimating N 2 fixation using the 15 N natural abundance method, Plant and Soil, vol.255, pp.495-502, 2003.

A. Sy, E. Giraud, P. Jourand, N. Garcia, A. Willems et al., Methylotrophic Methylobacterium bacteria nodulate fix nitrogen in symbiosis with legumes, Journal of Bacteriology, vol.183, pp.214-220, 2001.

A. Sy, G. E. Samba, R. De-lajudie, P. Gillis, M. Dreyfus et al., Certaines légumineuses du genre Crotalaria sont spécifiquement nodulées par une nouvelle espèce de Methylobacterium, Canadian Journal of Microbiology, vol.47, pp.503-508, 2001.
DOI : 10.1139/w01-044

M. J. Trinick, Relationships amongst the fast-growing rhizobia of Lablab purpureus, Leucaena leucocephala, Mimosa spp., Acacia farnesiana and Sesbania grandiflora and their affinities with other rhizobial groups, Journal of Applied Bacteriology, vol.49, pp.39-53, 1980.

M. J. Trinick, M. Miller, and P. A. Hadobas, Formation and structure of root nodules induced on Macroptilium atropurpureum inoculated with various species of Rhizobium, Canadian Journal of Botany, vol.69, pp.1520-1532, 1991.

P. Vandamme, J. Goris, W. M. Chen, P. De-vos, and A. Willems, Burkholderia tuberum sp. nov. and Burkholderia phymatum sp. nov., nodulate the roots of tropical legumes, Systematic and Applied Microbiology, vol.25, pp.507-512, 2002.

G. Van-den-eede, R. Deblaere, K. Goethals, M. Van-montagu, and M. Holsters, Broad host range and promoter selection vectors for bacteria that interact with plants, Molecular Plant-Microbe Interactions, vol.5, pp.228-234, 1992.

J. Vasse, F. De-billy, S. Camut, and G. Truchet, Correlation between ultrastructural differentiation of bacteroids and nitrogen fixation in alfalfa nodules, Journal of Bacteriology, vol.172, pp.4295-4306, 1990.

W. G. Weisburg, S. M. Barns, D. A. Pelletier, and D. J. Lane, 16S ribosomal DNA amplification for phylogenetic study, Journal of Bacteriology, vol.173, pp.697-703, 1991.

B. Van-wyk, Podalyrieae, Legumes of the World. Kew: Royal Botanic Gardens, pp.267-271, 2005.