Sinorhizobium melilotiSymbiosisMedicago sativaSinorhizobiumMedicago truncatulaNitrogen FixationBacterial ProteinsSinorhizobium frediiDNA, IntergenicMedicagoPlant Root NodulationGene Expression Regulation, BacterialRoot Nodules, PlantBacteriaRhizobiumGenes, BacterialMolecular Sequence DataRhizobiaceaePolysaccharides, BacterialPlant RootsDNA, BacterialFabaceaeRhizobium leguminosarumMelilotusSequence Analysis, DNABase SequenceLuteolinGenome, BacterialMutagenesis, InsertionalMutation