ISHS Acta Horticulturae 697: International Symposium on Soilless Culture and Hydroponics
UPTAKE OF FE(O,O-EDDHA) ISOMERS BY STRATEGY I AND II PLANTS |
| Authors: | S. Alcañiz, M. Cerdán, M. Juárez, J.D. Jordá, D. Bermúdez, A. Sánchez |
| Keywords: | Fe (o,o-EDDHA), Strategy I, Strategy II, iron uptake, oats, pepper |
| Abstract:
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 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. | |
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