UPTAKE OF FE(O,O-EDDHA) ISOMERS BY STRATEGY I AND II PLANTS

S. Alcañiz, M. Cerdán, M. Juárez, J.D. Jordá, D. Bermúdez, A. Sánchez
2005 Acta Horticulturae  
Higher plants are able to develop two different strategies in order to increase iron availability in soils. Strategy I is developed by dicot and non-graminaceous monocot species. Strategy II is developed by graminaceous species. In soils and/or irrigation waters with high bicarbonate content, the activity of Strategy I can be neutralized, causing severe iron deficiency in crops that must be supplied with iron. The iron fertilizer that yields better result consist of the iron chelate
more » ... chelate Fe(o,o-EDDHA). This chelate forms two different groups of isomers when the chelating agent (o,o-EDDHA) is linked to iron: the meso (50%) and racemic (50%) isomers. These isomers show different stability constants, the isomer d,l-racemic is 500-fold more stable than the meso form. The aim of this research was to test if plants took up iron in a different way depending on the isomer and the kind of strategy developed by plants under Fe deficiency. The meso and d,l-racemic Fe(o,o-EDDHA), the free (o,o-EDDHA) and pH were measured in the nutrient solution. Oats plants (Strategy II) took up iron from both Fe(o,o-EDDHA) isomers equally and did not take up the chelating agent. Pepper plants (Strategy I) took up only iron from the meso form and (o,o-EDDHA) was likely kept temporally in the root apoplast.
doi:10.17660/actahortic.2005.697.70 fatcat:j6le432ecrcyhdusjnevfqoe3a