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. 1972 Aug;50(2):208–213. doi: 10.1104/pp.50.2.208

Obligatory Reduction of Ferric Chelates in Iron Uptake by Soybeans

Rufus L Chaney a,1, John C Brown a, Lee O Tiffin a
PMCID: PMC366111  PMID: 16658143

Abstract

The contrasting Fe2+ and Fe3+ chelating properties of the synthetic chelators ethylenediaminedi (o-hydroxyphenylacetate) (EDDHA) and 4,7-di(4-phenylsulfonate)-1, 10-phenanthroline (bathophenanthrolinedisulfonate) (BPDS) were used to determine the valence form of Fe absorbed by soybean roots supplied with Fe3+-chelates. EDDHA binds Fe3+ strongly, but Fe2+ weakly; BPDS binds Fe2+ strongly but Fe3+ weakly. Addition of an excess of BPDS to nutrient solutions containing Fe3+-chelates inhibited soybean Fe uptake-translocation by 99+%; [Fe(II) (BPDS)3]4− accumulated in the nutrient solution. The addition of EDDHA caused little or no inhibition. These results were observed with topped and intact soybeans. Thus, separation and absorption of Fe from Fe3+-chelates appear to require reduction of Fe3+-chelate to Fe2+-chelate at the root, with Fe2+ being the principal form of Fe absorbed by soybean.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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