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Date of Article: 24-03-2004 |
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Thlaspi caerulescens Thlaspi caerulescens (alpine pennycress; family Brassicaceae) can hyperaccumulate very large amounts of zinc (Zn) (greater than 1% on a dry weight basis) in its shoot tissues. This feature is of interest for developing novel plant-based strategies to remove Zn from contaminated land (phytoextraction).
In theory, it is possible to accelerate breeding strategies for plants with improved phytoextraction potential by understanding the mechanisms of Zn uptake by roots and its accumulation within the shoots of hyperaccumulator species such as T. caerulescens. We have used modelling studies to show that the movement of Zn to the xylem of T. caerulescens cannot solely be via a symplastic pathway when roots are exposed to high Zn concentrations in the rhizosphere. Our studies reveal that the phytoextraction of Zn from soils will be limited by soil Zn-supply characteristics under many typical soil conditions. Thus, strategies to increase the Zn absorption power of the root by modifying Zn transporters in root cells may not be successful for enhancing Zn phytoextraction per se. Enhancing Zn availability and mobility in soils will be at least as important as understanding and manipulating Zn uptake by plants. Collaborators: University of Melbourne, Australia (Images courtesy of S. N. Whiting and A. J. M. Baker) This article first appeared in the HRI Annual Report (2002-2003)
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