Effects Of Cd²⁺ Stress On Antioxidant System Of Jatropha Curcas L. And Root System Simulation

Cadmium (Cd) has stronger mobility, easy enrichment in biological and other characteristics; it is one of the most toxic heavy metals to organisms. The cadmium pollution is becoming more and more serious, seriously impact on agricultural production and human health, so attracted wide attention. In this paper, in order to study the cadmium stress on Jatropha curcas L. seedlings, we chose Jatropha curcas L. as the research object. First of all, the germination under different concentrations of cadmium on Jatropha curcas L. seeds was studied; Secondly, determined the content of soluble protein and MDA, five kinds of antioxidant activity, content of two kinds of antioxidant under cadmium stress in leaves of Jatropha curcas L. seedlings were determined. Finally, we simulated the condition of Jatropha curcas L. root growth under Cd2+stress.The main results of this study are as follows:(1) Effects of the Germination on Jatropha curas L. seeds under Cd2+stress. When the concentration of Cd2+was O.lmmol/L, compared with the control group, the seed germination rate, germination potential and germination index had small effection.While with an increase of the concentration of Cd2+, germination inhibition was significant. When the concentration of Cd2+was0.5mmol/L, the inhibition was very significant.(2) Effects of antioxidant system on Jatropha curcas L. under Cd2+stress.①With the increase of Cd2+concentration, compared with the control group, the content of soluble protein in Jatropha curcas L. seedlings leaf decreased, the content of MDA increased; POD, SOD, CAT, APX and GR activity increased, and the content of ASA and GSH decreased, the content of DHA and GSSG increased, the ratio of ASH/DHA and GSH/GSSG decreased during the time of0～60h,;②With the growth of treatment time of Cd2+stress, the content of soluble protein in the leaves of Jatropha curcas L. seedling decreased, the MDA content increased; POD, SOD, CAT, APX and GR activity increased firstly and then decreased, the content of ASA and GSH decreased; and the content of DHA and GSSG increased, the ratio of ASH/DHA and GSH/GSSG decreased.(3)The effect and simulate of Jatropha curcas L. seedlings growth under Cd2+stress. The test set4concentration levels, with the increase of Cd2+concentration, Jatropha curcas L. underground roots were inhibited, and roots number, length were reduced.The above results showed that, the Cd2+stress inhibited the seed germination; through inhibiting increase antioxidase activity affected the normal growth of Jatropha curcas L. seedlings; and reduced the number and length of roots.