The Greater Sudbury Region (GSR) is one of the most ecologically disturbed regions of Canada. Recent studies have shown that Betula papyrifera accumulate metals in roots or leaves. The main objectives of the present study were to 1) determine the effects of copper treatment on B. papyrifera under controlled conditions and 2) assess the level of expression of genes associated with copper resistance in B. papyrifera populations from metal-contaminated and uncontaminated areas. Significant differences for damage rating were observed among copper dosages after eight days of treatment. There was also a trend of reduced plant growth as the dosage increased. RT-qPCR analysis showed 2x to 25x increase in leaves compared to roots of the expression of the gene for Multi-drug resistance associated protein (MRP4) belonging to the subfamily of ATPbinding cassette (ABC) transporters. A significant upregulation (ranging from 3x to 8 x increase) of