Gene expression profiles in roots of hydroponically grown Arabidopsis treated with 0.125 mM gold

Gold is widely considered to be a biologically inert element; however, it can elicit a profound biological response in plants. Plants can be exposed to significant levels of this precious metal in the environment from naturally occurring sources, as the result of mining activities or more recently resulting from the escalating use of nanoparticles in industry. In this microarray study we have investigated the gene expression response of Arabidopsis thaliana (Arabidopsis) to gold. Although the uptake of metal cations by plant transporters is well characterised, little is known about the uptake of gold, which exists in soil predominantly in a zero-valent state (Au0). We used this study to monitor the expression of candidate genes involved in metal uptake and transport. These show the down-regulation of a discreet number of genes known to be involved in the transport of copper, cadmium, nickel and iron. The experiment comprised three replicate jars of hydropnically-grown Arabidopsis, each treated with 0.125 mM KAuCl4, and three replicate jars of hydropnically-grown Arabidopsis which were treated with water only.