Abstract
Plants and microbes have enormous importance in our daily life. Iron is said to be the fourth most abundant element in the earth's crust from soil, still many plants face problem in uptaking iron because it is found in insoluble form, which severely restricts the bioavailability of this metal. In response to this, microorganisms present in soil such as Pseudomonas sp., Enterobacter genera, Bacillus and Rhodococcus produce special iron carriers or iron-binding compounds called as ‘siderphores’ or ‘siderochromes’. This paper is an attempt to review the importance of siderphores in enhancing plants’ iron utilisation strategies, the mode of transport of siderophores along with iron across the memberane and depending on the difference in their chemical structure, functional moiety and their source of isolation of four different types of siderophore (hydroxamates, catecholates, carboxylates and siderophore with mixed ligand). Siderophore and their derivative have large application in agriculture as to increase soil fertility and as biocontrol for fungal pathogen. This review unlike other reviews includes (1) types of siderophore, (2) the structural difference amongst them, (3) siderophore biosynthesis, (4) transport mechanism, (5) the genetics of siderophore and (6) their efficacy in human life.