Minimal gene set from Sinorhizobium (Ensifer) meliloti pSymA required for efficient symbiosis with Medicago

Reduction of N₂ gas to ammonia in legume root nodules is a key component of sustainable agricultural systems. Root nodules are the result of a symbiosis between leguminous plants and bacteria called rhizobia. Both symbiotic partners play active roles in establishing successful symbiosis and nitrogen fixation: while root nodule development is mostly controlled by the plant, the rhizobia induce nodule formation, invade, and perform N₂ fixation …