Fe Uptake from Meso and d,l-Racemic Fe(o,o-EDDHA) Isomers by Strategy I and II Plants

One of the most efficient fertilizers to correct Fe deficiency in calcareous soils and waters with high bicarbonate content is based on ferric ethylenediamine-N,N‘-bis(o-hydroxyphenylacetic) acid [Fe(o,o-EDDHA)]. Fe(o,o-EDDHA) forms two groups of geometric isomers known as meso and d,l-racemic. To determine the Fe uptake from meso and d,l-racemic Fe(o,o-EDDHA), four iron-efficient plants, two plants representative of strategy I (tomato and pepper) and two plants representative of strategy II (wheat and oats), were grown in hydroponic culture. Results indicated that strategy II plants took up iron from both Fe(o,o-EDDHA) isomers equally. However, strategy I plants took mainly the iron associated with the meso form (the lowest stability isomer). Keywords: Fe(o,o-EDDHA) isomers; strategy I plants; strategy II plants; iron uptake; Lycopersicon esculentum Mill.; Capsicum annuum L.; Triticum aestivum; Avena sativa L.