Physiological characteristics of Ficus tikoua under antimony stress
(1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China)
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China)
Abstract: A greenhouse culture experiment was used to evaluate the effects of antimony (Sb) stress on Ficus tikoua (F. tikoua). The results showed that the growth of F. tikoua leaves was significantly inhibited when Sb concentration was higher than 30 μmol/L, and no significantly inhibitory effect of Sb on the roots and stems of F. tikoua was found in all the treatments, implying that leaves were more sensitive to Sb toxicity than roots and stems. Antimony concentration in the roots was higher than that in the stems and leaves. To reduce reactive oxygen species (ROS) level in the F. tikoua, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased with Sb treatments, but the SOD and CAT were more early active than POD. Although the decrease of chlorophyll content with high Sb treatments (450 μmol/L) was observed at the end of the experiments, the positive impact on chlorophyll content was observed with all the Sb treatments at the early period. No significant difference of the maximum quantum efficiency of PSII and quantum yield of PSII electron transport values with different Sb treatments was observed at the end of this experiment, suggesting that the photosynthesis was not inhibited with Sb concentration below 450 μmol/L. The results implied a certain tolerance to Sb stress for F. tikoua. This meets the essential condition for utilization in Sb contamination environments.
Key words: antimony; biomass; antioxidant enzyme activity; F. tikoua; chlorophyll fluorescence