Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2006
Publication Date: 7/1/2006
Citation: Milner, M., Pence, N., Coughlin, S., Seib, L., Kochian, L.V. 2006. Expression profiling of zn and other metal related genes in thlaspi caerulescens [abstract]. American Society of Plant Biologists Annual Meeting. p. 101. Interpretive Summary:
Technical Abstract: Previous research has shown that Thlaspi caerulescens is able to hyperaccumulate as much as 30,000 ppm zinc and 10,000 ppm cadmium in its shoots. In an attempt to better understand the ability of this plant to tolerate and accumulate such high levels of toxic metals, we looked at the expression of genes controlling movement of zinc, cadmium and other metals throughout the plant. We have previously shown that certain genes that play a role in zinc homeostasis and transport are overexpressed in T. caerulescens when compared to non-accumulators such as Thlaspi arvense and Arabidopsis. We believe that this hyperexpression plays a significant role in metal hyperaccumulation in T. caerulescens. To understand if this gene expression phenotype is specific to metal transporter genes or represents a broader expression profile for a whole suite of metal-related genes, we looked at expression of known and novel genes within three Brassica species that represent the range of metal hyperaccumulation: T. caerulescens, T. arvense, and Arabidopsis thaliana. Through analysis of Agilent Arabidopsis microarrays, as well as Northern and real time RT-PCR approaches, we are studying the expression levels of a wide range of genes in response to changes in plant Zn status. These findings are being integrated with physiological analyses of Zn accumulation (root Zn influx) in these three species grown under low and high Zn regimes. We have found that expression of many metal-related genes are considerably higher in T. caerulescens when compared to non-accumulator plant species. This suggests that alterations in gene expression is partially responsible for the observed phenotype of T. caerulescens to hyperaccumulate zinc and cadmium.