Sinorhizobium melilotiSymbiosisNitrogen FixationSinorhizobiumMedicago sativaFabaceaeSinorhizobium frediiMedicago truncatulaMedicagoPlant Root NodulationRoot Nodules, PlantBacterial ProteinsGene Expression Regulation, BacterialRhizobiumRhizobiaceaePlant RootsGenes, BacterialPolysaccharides, BacterialMolecular Sequence DataRhizobium leguminosarumMelilotusLuteolinDNA, BacterialMutagenesis, InsertionalGenome, BacterialMutationGenetic Complementation TestSequence Analysis, DNAGalactansAgrobacterium tumefaciensBradyrhizobium4-ButyrolactoneBase Sequence