Abstract:In this study, Cu tolerance and accumulation characteristics in Melissa officinalis were investigated by some indexes, such as biomass, chlorophyll contents, antioxidant enzyme activities, soluble protein (SP), malondialdehyde (MDA) and Cu contents in plants under different concentrations of Cu2+ (0, 200, 400, 800, 1 000 mg·kg-1) through pot experiments was measured after 0, 7, 14, 21 and 28 days. The results show that: (1) at the same treatment time, there was a similar trend that a significant increase at low doses (200 and 400 mg·kg-1), while an inhibitory at high doses (800 and 1 000 mg·kg-1) in most of indexes except MDA content. Furthermore, the statistical results showed that differences were significant between high doses group (800 and 1 000 mg·kg-1) and those of low dose groups (200 and 400 mg·kg-1) (P<0. 05). Unlike these changes of other indexes, the variation trend of index MDA was growing 14 days ago and decreasing at 1 000 mg·kg-1 Cu2+ concentration. (2) As the Cu2+ dose increasing, the total Cu concentration in plants reached up peak at 400 mg·kg-1 (0.71 mg each pot) then declined. (3) Throughout the experiments, these indexes of tolerance and the bioconcentration factors of M. officinalis were more than 0.5 and 1, respectively. Both the index of tolerance and the bioconcentration factor decreased with the Cu2+ concentration increasing after 28 days, which explored that M. officinalis has some certain of tolerance ability and accumulation capacity for Cu. The results suggested that M. officinalis has the potential to be a promising plant for phytoremediation in Cucontaminated soil.