Abstract:
To study the effect of lead stress on growth, lead absorption and related physiological indexes in
Jatropha curcas, a pot experiment was conducted with soils treated with the Pb concentration of 0, 200, 400, 800,1600,and 3200 mg·kg
-1,separately.Results show that growth of
J.curcas was significantly inhibited when soil
w(Pb)≥800 mg·kg
-1.With increasing Pb concentration in the soilm,the Pb contents in various parts of the plant increased,showing a decreasing order of root,leaf,and stem.And when soil
w(Pb) was ≥800 mg·kg
-1, the actioxidant enzymes,i.e. superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT),and the contents of proline,soluble sugar,and acid thiol (SH)in the plant leaves were all increased significantly,however,the content of glutathione (GSH)would show a sharp rise only when soil
w(Pb) reached up to 3200 mg·kg
-1.With increasing Pb concentration in the soil,the content of soluble protein rose first and then declined,and peaked when soil
w(Pb) was at 400 mg·kg
-1.The above-described changes in physiology of
J.curcas reduced Pb toxicity to the plant to a certain extent.Principal component anlysis (PCA) revealed that the result of clustering of the treatment of Pb stress accorded with the law of the changes in biomass and physiological indices of
J.curcas.Among the physiological indices of
J.curcas,POD activity and soluble sugar content were major contributors to alleviating Pb toxicity to the plant.The findings of the reasearch suggest that
J.curcas has great potential for phytoremedying lead polluted soils.