Sinorhizobium frediiSinorhizobiumNitrogen FixationSinorhizobium melilotiSymbiosisSoybeansPlant Root NodulationFabaceaeRhizobiumGlycyrrhiza uralensisMedicago sativaGenes, BacterialBacterial ProteinsNitrogenaseGene Expression Regulation, BacterialRoot Nodules, PlantRhizobiaceaeMolecular Sequence DataPolysaccharides, BacterialMedicago truncatulaAcetyleneMutationPlant RootsMedicagoRhizobium leguminosarumBradyrhizobium