Submitted to: Plant Physiology
Publication Type: Abstract Only
Publication Acceptance Date: 6/13/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Phytoremediation of soils contaminated with heavy metals requires the understanding of plant metal transport and tolerance. Thlaspi caerulescens tolerates and accumulates very high concentrations of Zn (40,000 ug/g ) and Cd (2000 ug/g) in the shoot. As T. caerulescens is small and slow growing, isolation and characterization of Zn/Cd hyperaccumulation genes may allow expression in higher biomass plant species for efficient and economical contaminated soil clean up. Our studies of have shown enhanced Zn transport into T. caerulescens roots and shoots compared to the related non-accumulating species Thlaspi arvense. We also have showed altered regulation of ZNT1, a Zn/Cd transporter, contributing to the high Zn uptake (see Pence et al. poster). A number of approaches are being employed to characterize ZNT1 and identify other genes involved in hyperaccumulation. For tissue localization studies, in situ RT-PCR is being employed to look at cell and tissue-specific ZNT1 expression, while a ZNT1-specific antibod is being used for protein localization and analysis of transporter protein abundance. Also, microarray research has been initiated in Arabidopsis, to identify additional Zn transport, tolerance and nutrition-related genes whose homologues in T. caerulescens will be studied for differential expression and involvement in heavy metal hyperaccumulation. Finally, research is also underway in our laboratory to study the physiological properties of micronutrient transporters, including ZNT1, using heterologous expression in Xenopus oocytes and these findings will be presented.