Plant and Soil

, Volume 374, Issue 1, pp 497–512

Contribution of Cd-EDTA complexes to cadmium uptake by maize: a modelling approach

  • Jean-Marc Custos
  • Christian Moyne
  • Tiphaine Treillon
  • Thibault Sterckeman
Regular Article

DOI: 10.1007/s11104-013-1906-7

Cite this article as:
Custos, JM., Moyne, C., Treillon, T. et al. Plant Soil (2014) 374: 497. doi:10.1007/s11104-013-1906-7

Abstract

Background and aims

Chelant-enhanced phytoextraction has given variable and often unexplained experimental results. This work was carried out to better understand the mechanisms of Cd plant uptake in the presence of EDTA and to evaluate the contributions of Cd-EDTA complexes to the uptake.

Method

A 1-D mechanistic model was implemented, which described the free Cd2+ root absorption, the dissociation and the direct absorption of the Cd-EDTA complexes. It was used to explain Cd uptake by maize in hydroponics and in soil.

Results

In hydroponics, the addition of EDTA caused a decrease in Cd uptake by maize, particularly when the ratio of total EDTA ([EDTA]T) to total Cd ([Cd]T) was greater than 1. At [Cd]T = 1 μM, when [EDTA]T/[Cd]T < 1, the model indicated that Cd uptake was predominantly due to the absorption of free Cd2+, whose pool was replenished by the dissociation of Cd-EDTA. When [EDTA]T/[Cd]T > 1, the low Cd uptake was mostly due to Cd-EDTA absorption. In soil spiked with 5 mg Cd kg−1, Cd uptake was not affected by the various EDTA additions, because of the buffering capacity of the soil solid phase.

Conclusions

Addition of EDTA to soil increases Cd solubility but dissociation of Cd-EDTA limits the availability of the free Cd2+ at the root surface, which finally reduces the plant uptake of the metal.

Keywords

CadmiumEDTAPhytoextractionMetal-ligand complexModellingRoot uptake

Abbreviations

EDTA

Ethylenediaminetetraacetic acid

NTA

Nitrilotriacetic acid

EDDS

Ethylenediamine disuccinic acid

MES

Morpholinoethane sulfonic acid

Supplementary material

11104_2013_1906_MOESM1_ESM.docx (929 kb)
ESM 1(DOCX 928 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Jean-Marc Custos
    • 1
    • 2
  • Christian Moyne
    • 3
    • 4
  • Tiphaine Treillon
    • 1
    • 2
  • Thibault Sterckeman
    • 1
    • 2
  1. 1.Laboratoire Sols et EnvironnementUniversité de LorraineVandœuvre-lès-Nancy CedexFrance
  2. 2.Laboratoire Sols et EnvironnementINRAVandœuvre-lès-Nancy CedexFrance
  3. 3.Laboratoire d’Énergétique et de Mécanique Théorique et AppliquéeUniversité de LorraineVandœuvre-lès-Nancy CedexFrance
  4. 4.Laboratoire d’Énergétique et de Mécanique Théorique et AppliquéeCNRSVandœuvre-lès-Nancy CedexFrance