Role of Rhizobia for Sustainable Agriculture: Lab to Land

Rhizobia is symbiotic diazotrophic soil bacteria infecting the roots of leguminous plants to form root nodules to fix molecular atmospheric nitrogen (N2) with the aid of nitrogenase enzyme, turning it into a more readily usable form for plants. Rhizobia also possess plant growth-promoting (PGP) properties witnessed by a series of molecular dialogue between the plant and the bacteria. Unraveling such mechanisms gave the insight toward multifunctional approach of rhizobia in the rhizosphere of legumes and compatible plants. Bioavailability of nutrients in the soil is enriched by rhizobial action due to metal solubilization and siderophore activity. The combined activity of phytohormones, enzymes, and siderophores contributes toward the growth and development of the concerned plant along with easy nutrient uptake and phytoremediation. Besides, rhizobia aid in biocontrol through antibiosis, parasitism, or competition with different pathogens for essential nutrient uptake. This has made it an important candidate for sustainable agriculture in various economies across the globe.