Plants employ mechanisms that promote Fe availability in the rhizosphere and plant. Dicot and monocot species, with the
exception of members of the family Poaceae, have developed a strategy (Strategy I) that involves the induction of a ferric chelate reductase (FC-R; EC 1.16.1.17) in roots that converts Fe(III) to Fe(II),
which can then be taken up by an Fe(II) transporter [2,3]. Excretion of organic acids from roots to the rhizosphere can improve Fe availability further, and accumulation of these compounds in Fedeficient plants can also stimulate long-distance transport of the metal [4].