麻疯树对铅胁迫的生理耐性研究

通过盆栽试验研究土壤中不同浓度（0、200、400、800、1 600和3 200 mg.kg-1）Pb胁迫对麻疯树生长、Pb吸收及相关生理指标的影响。结果表明,当土壤w（Pb）≥800 mg.kg-1时,麻疯树生长受到明显抑制;麻疯树植株不同部位Pb含量随土壤Pb浓度的升高而增加,且各部位Pb含量从高到低依次为根、叶和茎;当土壤w（Pb）≥800mg.kg-1时,麻疯树叶中超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,以及可溶性糖、脯氨酸和酸溶性巯基（SH）含量均显著提高,而谷胱甘肽（GSH）含量仅在土壤w（Pb）为3 200 mg.kg-1时才显著增加;可溶性蛋白质含量随Pb浓度的增加呈倒＂W＂型变化,当土壤w（Pb）为400 mg.kg-1时,其含量最大;上述生理指标的变化可缓解重金属Pb对麻疯树的毒害。主成分分析结果表明Pb胁迫处理的聚类结果与各处理麻疯树生物量及生理指标的变化规律相吻合,POD活性和可溶性糖含量对缓解重金属Pb毒害的贡献较大。可见,麻疯树在Pb污染土壤修复中具有一定的应用前景。

Physiological Tolerance of Jatropha curcas to Lead Stress

To study effect of lead stress on growth,lead absorption and related physiological indexes of Jatropha curcas,a pot experiment was conducted with soils treated with the Pb concentration of 0,200,400,800,1 600,and 3 200 mg·kg-1,separately.Results show that growth of J.curcas was significantly inhibited when soil w（Pb） was ≥800 mg·kg-1.With increasing Pb concentration in the soil,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 activities of antioxidant 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 3 200 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 analysis（PCA） revealed that the result of clustering of the treatments 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 research suggest that J.curcas has great potential for phytoremedying lead polluted soils.