Phosphate-Solubilizing Microorganisms in Sustainable Agriculture: Genetic Mechanism and Application

Abstract

Phosphorus (P) is the second important nutrient in terms of plant requirement and uptake. Though it is present in the soil in both organic and inorganic forms, its accessibility is constrained as it occurs mostly in insoluble forms. Additional requirement of P to satisfy nutritional requirements of the crop is usually supplemented as chemical P fertilizer. A number of soil microorganisms named phosphate-solubilizing microorganisms (PSMs) have been tested for solubilizing/mineralizing insoluble soil P, releasing in soluble form and making it available for plant uptake. PSMs are environment-friendly and deliver P to plants in a more sustainable manner. The present chapter focuses on the biochemical, molecular, and genetic mechanisms of P release by different PSMs. Phosphorus solubilization through diffusion of strong organic acids produced in the periplasm of the organism, into the adjacent soil environment, is one of the important mechanisms for P solubilization and is genetically controlled. The use of PSM is a promising approach to develop and fulfill P demand of the growing crop without causing any environmental hazard.