[Response of Vetiveria zizanioides to Pb2+ stress]

The study on the eco-physiological indices of V. zizanioides under Pb2+ stress showed that with the increase of Pb2+ concentration (0 approximately 8 mmol x L(-1)) in water culture, the growth of V. zizanioides seedlings was badly influenced. Their leaves' conductivity increased, while SOD activity increased first and decreased then, but still higher than control. There was a positive correlation between SOD activity and Pb2+ concentration. POD and CAT activities were also increased first and decreased then, but when the Pb2+ concentration was > 4 mmol x L(-1), these enzyme activities were lower than the control, and had a significantly negative correlation with Pb2+ concentration. It was considered that the increase of enzyme activities was resulted from the adaptability of V. zizanioides stressed by Pb2+, while high concentration Pb2+ had an inhibitory effect on enzyme activities.