Physiological evidence for a high-affinity cadmium transporter highly expressed in a Thlaspi caerulescens ecotype

A - Papers appearing in refereed journals

Lombi, E., Zhao, F-J., McGrath, S. P., Young, S. D. and Sacchi, G. A. 2001. Physiological evidence for a high-affinity cadmium transporter highly expressed in a Thlaspi caerulescens ecotype. New Phytologist. 149 (1), pp. 53-60.

AuthorsLombi, E., Zhao, F-J., McGrath, S. P., Young, S. D. and Sacchi, G. A.
Abstract

Uptake kinetics and translocation characteristics of cadmium and zinc are presented for two contrasting ecotypes of the Cd/Zn hyperaccumulator Thlaspi caerulescens, Ganges (southern France) and Prayon (Belgium). Experiments using radioactive isotopes were designed to investigate the physiology of Cd and Zn uptake, and a pressure-chamber system was employed to collect xylem sap. In contrast to similar Zn uptake and translocation, measurements of concentration-dependent influx of Cd revealed marked differences between ecotypes. Ganges alone showed a clear saturable component in the low Cd concentration range; maximum influx V(max) for Cd was fivefold higher in Ganges; and there was a fivefold difference in the Cd concentration in xylem sap. Addition of Zn to the uptake solution at equimolar concentration to Cd did not decrease Cd uptake by Ganges, but caused a 35% decrease in Prayon. There is strong physiological evidence for a high-affinity, highly expressed Cd transporter in the root cell plasma membranes of the Ganges ecotype of T. caerulescens. This raises evolutionary questions about specific transporters for non-essential metals. The results also show the considerable scope for selecting hyperaccumulator ecotypes to achieve higher phytoextraction efficiencies.

KeywordsPlant Sciences
Year of Publication2001
JournalNew Phytologist
Journal citation149 (1), pp. 53-60
Digital Object Identifier (DOI)doi:10.1046/j.1469-8137.2001.00003.x
Open accessPublished as non-open access
Funder project or code443
512
ISSN0028646X
PublisherWiley

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