Similar results were observed at all the lower concentrations (5, 10, 20, 40 and 80 ppm) wherein the data suggest an increase in uptake with increased exposure time and concentration for both BJ and MS. ICP-OES analysis of plant tissues revealed that at each exposure concentration, the majority of Au was associated with the roots. For all treatments, Au uptake in the roots and shoots was greater at 360 h than at lesser exposure times.