Primers used in this study for PCR and Sanger sequencing.

<p>Primers used in this study for PCR and Sanger sequencing.</p

Radar of <i>Mesorhizobium</i> strain optical density when grown in TY broth medium in 200 ul in a 96 well microplate with different concentrations of NaCl (100 to 500 mM).

<p>The data presented here are at 41h post-inoculation with 0.05 OD as a starting point. Radars at 24h and 68h are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.s002" target="_blank">S1 Fig</a>., and histograms of growth for each strain at 41h are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.s003" target="_blank">S2 Fig</a>.</p

Genome characteristics of strains sequenced as part of this study as well as reference genomes used for average nucleotide identities calculations (ANI).

<p>^£: Gold id refers to the Genome on-line database (<a href="http://www.genomesonline.org/" target="_blank">http://www.genomesonline.org/</a>);</p><p>^$: Project id at EBI (<a href="http://www.ebi.ac.uk/" target="_blank">http://www.ebi.ac.uk/</a>); genomes were submitted to the European Nucleotide Archive database under this project ID.</p><p>§: NCBI taxon number at <a href="http://www.ncbi.nlm.nih.gov/taxonomy" target="_blank">http://www.ncbi.nlm.nih.gov/taxonomy</a>.</p><p>%: Strain MAFF303099 was assigned to the <i>M. huakuii</i> species in previous reports [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.ref065" target="_blank">65</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.ref066" target="_blank">66</a>]. AN: Accession Number.</p><p>Genome characteristics of strains sequenced as part of this study as well as reference genomes used for average nucleotide identities calculations (ANI).</p

Localization of sampling sites in Senegal.

<p>Sampling sites are indicated in blue (D = Dahra, K = Kamb, B = Bambey, F = Foundiougne, Ng = Ngane, V = Vélor, Nd = Ndiafate, No = Nonane, G = Goudiry). The red color indicates salt affected soils (Electroconductivity >4000 μS cm^-1). Background colors indicate the different climatic zones of Senegal: light yellow = Sahelian zone (annual rainfall 250–500 mm), Dark yellow = Sudano-Sahelian zone (annual rainfall 500–900 mm), light green = Sudanean zone (annual rainfall 900–1100 mm), dark green = Guinean zone (annual rainfall > 1100 mm).</p

Bayesian phylogeny of the 5 markers alignment (<i>atp</i>D-<i>dna</i>J-<i>gln</i>A-<i>gyr</i>B-<i>rec</i>A) (A) and rep-PCR fingerprints (B) of the <i>Mesorhizobium</i> collection.

<p>The priors (estimated by ML) and run parameters for the Bayesian phylogeny are indicated on the left side of the tree. The tree shown is a 50% majrule consensus of all trees produced by the 4 Markov chains. Posterior probabilities (upper number) and bootstraps from 1000 replicates from a ML phylogeny (below number) are indicated at each tree nodes (/ indicate that there is no bootstrap available because the tree node was not common between the Bayesian tree and the ML tree). The scale bar indicates the number of substitutions per site. For the rep-PCR fingerprints (B), see the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#sec002" target="_blank">Mat&Methods</a> section. Each profile was numbered on the right side of the gel. Rep-PCR profiles were not obtained for ORS3400, ORS3598 and ORS1032.</p

Average nucleotide identities (ANI) between <i>Mesorhizobium</i> genomes

<p>Average nucleotide identities (ANI) between <i>Mesorhizobium</i> genomes</p

Bacterial collection of <i>Acacia</i> symbionts used in this study.

<p>Strains in bold indicate strain which genome was sequenced in draft. STM, culture collection of Laboratoire des Symbioses Tropicales et Méditerranéennes Montpellier, France. ORS, culture collection of the Laboratoire Commun de Microbiologie IRD/ISRA/UCAD Dakar, Senegal.</p><p>£: Tolerance to salt in mM as estimated in this study: the number indicates the concentration of salt tested at which the strain still grows.</p><p>&: Sud: Sudano-sahelian zone with 500–900 mm of annual rainfall; Sah: Sahelian zone with 300–500 mm of annual rainfall.</p><p>#: Soil ElectroConductivity (EC) in μS cm^-1.</p><p>* indicated salted soil according to FAO (>4000 μS cm-1.).</p><p>$: Site with numbers corresponds to sites in [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.ref022" target="_blank">22</a>].</p><p>GPS coordinates: Ndiafate 1: 14°03 753’N, 16°11 239’W; Ndiafate2: 14°03 914’N, 16°11 200’W; Velor1: 14°03 467’N, 16°11 243’W; Velor2: 14°03 466’N, 16°11 176’W; Nonane1: 14°18 187’N, 16°21 340’W; Nonane3: 14° 18 144′N, 16°21 163’W; Foundiougne5: 14°11 935’N, 16°26 836’W; Ngane1: 14°35 N, 16°42 W), Goudiry: 14°11N, 12°43W, Bambey: 14 42’N, 16 28’W; Kamb: 15 31′N, 15 25′W; Dahra: 15°21N, 15°29W. See [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.ref023" target="_blank">23</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117667#pone.0117667.ref024" target="_blank">24</a>] for detailed description of sampling sites.</p><p>Bacterial collection of <i>Acacia</i> symbionts used in this study.</p

Phylogeny of the 16S rRNA marker of the <i>Mesorhizobium</i> collection, built by neighbor joining from a distance matrix corrected by the Kimura-2 method.

<p>The scale bar indicates the number of substitutions per site. Numbers at tree nodes indicate % of bootstrap replicates.</p