Please use this identifier to cite or link to this item:
|Scopus||Web of Science®||Altmetric|
|Title:||Labile Cd complexes increase Cd availability to plants|
|Citation:||Environmental Science & Technology, 2006; 40(3):830-836|
|Publisher:||Amer Chemical Soc|
|Fien Degryse, Erik Smolders, and Roel Merckx|
|Abstract:||Dissolved trace metals are present in the environment as free ions and as complexes. Commonly used models to predict metal bioavailability consider the free ion as the major bioavailable species. However, increases in metal availability in the presence of metal complexes have repeatedly been found. We measured the uptake of cadmium (Cd) by spinach (Spinacia oleracea) from solution in absence or presence of synthetic ligands. At the same free ion concentration, the uptake of Cd ranged over almost 3 orders of magnitude and was largest in treatments with fast dissociating (i.e. labile) complexes. Similar results were found for the diffusional fluxes in these solutions, as measured with the DGT technique. The observed effect of Cd complexes on the plant uptake was in agreement with model calculations in which plant uptake was assumed to be governed by the diffusional flux. These results strongly suggest that Cd uptake is rate-limited by diffusion of the free ion to the root surface, even in stirred solutions. As a result, dissolved Cd complexes can increase Cd uptake, resulting in apparent exceptions from the free ion activity model. The magnitude of this increase depends both on the concentration and on the lability of the complexes. The free ion concept should therefore be reconsidered when transport limitations of the metal ion to the uptake site prevail.|
|Keywords:||Spinacia oleracea; Plant Roots; Cadmium; Soil Pollutants; Diffusion; Biological Availability; Models, Theoretical; Forecasting|
|Rights:||Copyright © 2006 American Chemical Society|
|Appears in Collections:||Agriculture, Food and Wine publications|
Files in This Item:
There are no files associated with this item.
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.