HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (14) Citing Articles via Google Scholar Google Scholar Articles by Shenker, M. Articles by Crowley, D.E. Search for Related Content PubMed PubMed Citation Articles by Shenker, M. Articles by Crowley, D.E. Agricola Articles by Shenker, M. Articles by Crowley, D.E. Related Collections Heavy Metals Plant and Environment Interactions

TECHNICAL REPORT
Plant and Environment Interactions

Phytosiderophores Influence on Cadmium Mobilization and Uptake by Wheat and Barley Plants

^a Dep. of Environmental Sciences, University of California, Riverside, CA 92521-0424
^b Dep. of Land, Air, and Water Resources, University of California, Davis, CA 95616
^c Dep. of Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76-100, Israel

* Corresponding author (Shenker{at}agri.huji.ac.il)

Received for publication February 14, 2000. A constant anthropogenic release of cadmium to the environment has resulted in a continuous buildup of Cd in soils. Uptake and accumulation of Cd in plant tissue and in grains may lead to food chain transfer to humans. Application of synthetic chelates was suggested to increase metal mobilization and facilitate phytoextraction as a means for the remediation of metal-polluted soils. However, most of the chelate-extracted metal may be leached rather than mobilized to plant roots. In contrast to the synthetic chelates added to soils, plant-produced chelators called phytosiderophores (PS) are excreted directly to the rhizosphere. Previous studies have shown that PS facilitate uptake of Zn and Fe by graminaceous plants. In this study, a two-step PS mediation of Cd uptake was hypothesized: (i) extraction and chelation in the soil solution, and (ii) delivery of the chelated Cd to the uptake system of the plant. We examined Cd extraction by PS, the synthetic chelate HEDTA [N-(2-hydroxyethyl)-ethylenediamine-triacetic acid], and a fungal siderophore rhizoferrin from solid-phase Cd phosphate at pH 7.3 with and without Fe competition in the presence of Ca and Mg as additional competing metals. While rhizoferrin did not extract Cd, PS and HEDTA did extract Cd even in the presence of Fe. Yet, uptake of Cd by wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) plants was not significantly influenced by Fe stress, but instead was controlled primarily by Cd²⁺ activity in solution. These results suggest that even though Cd may be mobilized by PS, there is no significant uptake of the Cd–PS complex by the plant roots.

Abbreviations: PS, phytosiderophores

This article has been cited by other articles:

				A. R. Meda, E. B. Scheuermann, U. E. Prechsl, B. Erenoglu, G. Schaaf, H. Hayen, G. Weber, and N. von Wiren Iron Acquisition by Phytosiderophores Contributes to Cadmium Tolerance Plant Physiology, April 1, 2007; 143(4): 1761 - 1773. [Abstract] [Full Text] [PDF]