Prevention of stress in iron metabolism of plants

Iron metabolism in plants is characterized by a dual requirement: (i) to have iron available in quantities sufficient for growth and for activities of essential processes, and (ii) to keep its concentrations low enough to prevent iron toxicity. This review is concerned with the ways in which plants may fulfil both conditions. Iron is extensively used as an electron carrier, as in cytochromes, ferredoxins, reductases and oxidases, but also in enzymes that do not catalyse a net electron transfer, such as aconitase. Synthesis or activation of these enzymes requires (as far as is known) the ferrous (Nakazawa etal. 1969; Bentleeru/. 1976; Jones 1983; Kennedy etal. 1983)orferric ion, under reducing conditions (Pagani et at. 1984).