Sinorhizobium frediiSinorhizobiumSinorhizobium melilotiSymbiosisNitrogen FixationMedicago sativaSoybeansMedicago truncatulaFabaceaePlant Root NodulationBacterial ProteinsGlycyrrhiza uralensisRhizobiumBacteriaGenes, BacterialPolysaccharides, BacterialMolecular Sequence DataGene Expression Regulation, BacterialRhizobiaceaeMutationMedicago