Molecular analysis of iron-deficient Graminaceous plants

Abstract

Graminaceous plants use mugineic acid family phytosiderophores (MAs), which are natural Fe(III) chelators, to acquire sparingly soluble Fe from the rhizosphere. The response of graminaceous plants to Fe-deficient conditions includes various processes involved in Fe homeostasis, the molecular components of which have been elucidated in recent years. The main processes are: (1) biosynthesis of MAs, (2) secretion of MAs, (3) uptake of Fe from the rhizosphere, (4) translocation and storage of Fe, and (5) regulation and signaling of the process. Regulation and signaling links the overall response to Fe availability and is thus of great importance. We recently identified two novel, Fe-deficiency-responsive, cis-Acting elements, IDE1 and IDE2, aiding in the elucidation of the underlying molecular mechanisms. The future production of Fe-deficiency-tolerant or high Fe-containing crops will be largely dependent on a comprehensive understanding of the molecular components of Fe homeostasis in graminaceous plants. © 2006 Springer.