An Eco-Friendly Approach for Managing Phosphorus Deficiency in Agricultural Soils: By Using Phosphate Solubilizing Microbe

Phosphorus (P) is one of the major essential macronutrients for plants and is applied to soil in the form of chemical P fertilizer, however the synthesis of chemical P fertilizer is a highly energy intensive processes, and has long term implications on the environment in terms of eutrophication, soil fertility depletion, destruction of micro-organisms and carbon footprint. Plants can use only a small amount of applied P, since 75–90% of added P is precipitated by metal–cation complexes, and rapidly becomes fixed in soils. Such environmental concerns have led to the search for sustainable way to provide P nutrition to crops. In this regards, phosphate solubilizing microorganism have been seen as best ecofriendly tools to generate solubilized P for plants, provide resistance against plant pathogens and stimulating the production of essential phytohormones. However, their performance under in situ conditions is not reliable and therefore needs to be improved by using either genetically modified strains or co-inoculation techniques. In recent years, several phosphatases encoding genes have been cloned and characterized which prove to be the excellent for plant growth. Therefore, genetic modification of phosphate solubilizing bacteria includes gene cloning, followed by their expression in selected rhizobacterial strains is an interesting approach. Besides phosphate solubilizing activity of microorganisms, this review article focuses on diversity of PSM, mechanism behind P solubilization, genes involved in phosphate solubilization, co-inoculation of PSB with other microbes. In addition, it also describes possible future scenario of their use.