The role of inositol in the environmental organic phosphate cycle

Cellular synthesis of phytic acid sequesters phosphates in the sugar inositol. Phytic acid in soil represents the most abundant form of organic phosphates. The supplementation of phytase or phytase-producing organisms has been considered as a strategy to improve usable soil phosphates. However, the impacts on the environmental flow of inositol, which is generated along with phosphate by phytase, have not been examined. In this review, we discuss the origin and nature of inositol produced in soil and the several possible destinations of inositol released by phytase activities. We emphasise how an improved understanding of soil inositol flow could help to provide new solutions to the phosphate shortage problem in agriculture. •Phytase activities in soil release phosphate as well as inositol from phytic acids.•Inositol in soil can be taken up by plant roots and microorganisms to make InsPs.•Inositol can also be degraded by some bacteria or stimulate plant-bacteria symbiosis.•Cellular inositol phosphate cycles regulate phosphate homeostasis and uptake.•Manipulating soil inositol cycles could help improve crop phosphate utilisation.