Abstract
We examined the gene expression profiles under Cd stress in roots and shoots using 22k oligo-nucleotide microarray in order to find out the genes involved in Cd tolerance and accumulation mechanisms in rice. Rice plants were exposed to 10 μ M CdCl 2 for 3 h, or to 1 μ M CdCl 2 for 1, 2, 3 and 8 d in hydroponic culture. Out of 21495 genes, 1207 genes were up-regulated whereas 519 genes were down-regulated more than two-fold in the root under 10 μ M Cd stress for 3 h. Focused on Cd-regulated transporter genes, some of ABC family transporters were highly up-regulated in roots, especially under 10 μ M Cd stress. It suggests that the Cd-regulated ABC transporters may be Cd exporter in rice roots. These are possibly related in Cd accumulation, translocation leading to the application of Cd reduction in rice grain.
