Effects of Pb and Zn Stresses on Protective Enzyme Activities of Pb Accumulator Plant Pseudostellaria maximowicziana(Franch.et Savat.) Pax

To understand the physiological and biochemical response of the lead-accumulator plant pseudostellaria maximowicziana (Franch.et Savat.) Pax to lead and zinc stresses, the pot experiment was used to study the protective enzymes (SOD, CAT and POD) activity and MDA content of pseudostellaria maximowicziana under lead and zinc stresses. The results showed as follows: with the increase of lead concentration, SOD activity of plants had a decreasing trend before increase, and with the increase of zinc concentration, SOD activity had an increasing trend. CAT activities of plants had a trend of increase and POD activities had a decreasing trend before with increase of lead and zinc concentrations increasing. However, with lead and zinc concentrations increasing, MDA contents of plants had a wavy trend. ANOVA showed that the differences of the three kinds of protective enzyme activities among the concentration of lead, lead-zinc interaction and MDA content were extremely significant. While those of SOD and CAT activities by zinc concentrations were extremely significant, and POD activity and MDA content were significant.