Plant Growth-Promoting Rhizobacteria (PGPRs): Functions and benefits

Abstract

Microorganisms have a fundamental contribution in the growth and development of plants by influencing their physiology and metabolism. Plant growth-promoting rhizobacteria (PGPRs) have been recognized as an important coevolutionary factor between plants and microbes. PGPRs show antagonistic and synergistic interactions with pathogenic microbes and plants, respectively. PGPRs produce a vast array of secondary compounds which facilitate agricultural yield as well as environmental cleanup. Since the extensive uses of chemical fertilizers and pesticides have caused deleterious impacts on almost all life forms in nature, researchers have shifted their attention on PGPRs throughout the world to improve the crop productivity. Moreover, the cost-effective and eco-friendly nature of PGPR makes them desirable candidate for application in crop disease management and integrated nutrient management. As such, now attention is also being focused to explore plant microbiome in order to identify new strains of microbes that can be used for enhancing plant growth and health in a sustainable way. The present chapter highlights the functions of PGPRs with special reference to its properties such as nutrient acquisition, mineral solubilization, siderophore production, phytohormone production, and tolerance to biotic as well as abiotic stresses. It also focuses on the benefits of PGPRs as biofertilizer, phytostimulant, and biocontrol agents and in rhizoremediation.