Effects of cadmium and lead on the growth and the activity of peroxidase and superoxide dismutase of blueberry plantlets in vitro

Abstract

To study the effects of cadmium and lead on the growth of blueberry (Vaccinium ashei Reade) plantlets in vitro and on the activity of peroxidase (POD) and superoxide dismutase (SOD) of blueberry shoots, Cd2+ and Pb2+ were added separately to a cultivation medium. The results show that 0.01 mM Cd2+ significantly inhibited the growth of blueberry shoots, and the height and fresh mass of the shoots were significantly lower than those of the control; 0.05 mM Cd2+ significantly inhibited the proliferation of the shoots; the inhibitory effect on the growth and proliferation of blueberry in vitro was enhanced with the increase of Cd2+ concentration. Also Pb2+ (0.10 - 1.00 mM) significantly decreased the proliferation of the shoots, but it did not decrease significantly the shoot height and fresh mass. After 20 d of Cd or Pb treatments, the POD and SOD activities of the shoots increased with the increase of their concentrations, and when the concentration was 1.00 mM, the POD and SOD activities were significantly higher than in the control; the effect of Pb2+ on POD and SOD activities was generally stronger than that of Cd2+. The upregulation of activities of antioxidative enzymes played an effective role in acclimatization to these stresses, especially to Pb stress.