Microbial siderophore – A boon to agricultural sciences

•Siderophores are organic iron chelating compounds of low molecular weight.•An adequate classification and typing of the siderophores has been presented.•Detection and quantitative estimation of siderophores have been described.•Siderophore application in the improvement and protection of crops stands out. Application of microbes or their products in our life is increasing as research on microbiology is proceeding. Many scientists are now paying much interest on research and proper application of microbial siderophores in agriculture for ecofriendly crop enhancement instead use of synthetic pesticide and fertiliser. Siderophore is an iron chelating organic compound with low molecular weight. Iron is very essential element for plants, microbes and animals including human. Several siderophores have been characterised and at the same time some siderophores are still uncharacterised and their functions are yet to be determined. Therefore, in this review critical analysis on siderophore producing microbes, their types, biosynthesis, and its mechanisms of absorption by plants, detection and estimation, and proper application in agri-fields are presented.