Characterization of the high affinity Zn transporter from Noccaea caerulescens, NcZNT1, and dissection of its promoter for its role in Zn uptake and hyperaccumulation
Article first published online: 23 APR 2012
No claim to original US government works. New Phytologist © 2012 New Phytologist Trust
Volume 195, Issue 1, pages 113–123, July 2012
How to Cite
Milner, M. J., Craft, E., Yamaji, N., Koyama, E., Ma, J. F. and Kochian, L. V. (2012), Characterization of the high affinity Zn transporter from Noccaea caerulescens, NcZNT1, and dissection of its promoter for its role in Zn uptake and hyperaccumulation. New Phytologist, 195: 113–123. doi: 10.1111/j.1469-8137.2012.04144.x
- Issue published online: 24 MAY 2012
- Article first published online: 23 APR 2012
- Received: 13 January 2012, Accepted: 7 March 2012
- cadmium (Cd) hyperaccumulation;
- Noccaea caerulescens;
- zinc (Zn) hyperaccumulation;
- Zn uptake
- •In this paper, we conducted a detailed analysis of the ZIP family transporter, NcZNT1, in the zinc (Zn)/cadmium (Cd) hyperaccumulating plant species, Noccaea caerulescens, formerly known as Thlaspi caerulescens. NcZNT1 was previously suggested to be the primary root Zn/Cd uptake transporter. Both a characterization of NcZNT1 transport function in planta and in heterologous systems, and an analysis of NcZNT1 gene expression and NcZNT1 protein localization were carried out.
- •We show that NcZNT1 is not only expressed in the root epidermis, but also is highly expressed in the root and shoot vasculature, suggesting a role in long-distance metal transport. Also, NcZNT1 was found to be a plasma membrane transporter that mediates Zn but not Cd, iron (Fe), manganese (Mn) or copper (Cu) uptake into plant cells.
- •Two novel regions of the NcZNT1 promoter were identified which may be involved in both the hyperexpression of NcZNT1 and its ability to be regulated by plant Zn status.
- •In conclusion, we demonstrate here that NcZNT1 plays a role in Zn and not Cd uptake from the soil, and based on its strong expression in the root and shoot vasculature, could be involved in long-distance transport of Zn from the root to the shoot via the xylem.