Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
Environ Sci Pollut Res Int. 2017 Dec;24(35):27476-27483. doi: 10.1007/s11356-017-0306-6. Epub 2017 Oct 4.
The biogeochemical cycling of sulfur (S) in soil has an important impact on the bioavailability of heavy metals and affects the utilization of soil polluted by heavy metals. In addition, S-containing compounds are involved in heavy metal detoxification. This study investigated the effects of S on the toxicity and bioavailability of copper (Cu) in castor (Ricinus communis L.) grown in Cu-contaminated mine tailings. The results showed that the application of S reduced the accumulation of Cu in castor and promoted its growth. With the addition of S, the malondialdehyde (MDA) content of castor leaves decreased significantly compared with control plants, indicating the alleviation of oxidative stress. Superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) content decreased significantly with the alleviation of oxidative stress. The sequential extraction of Cu fractions showed that the application of S significantly reduced the reducible Cu fraction, and increased the oxidizable Cu fraction. It also increased the residual Cu fraction in the soil. The transformation of chemical speciation reduced the bioavailability of Cu in soil, which then reduced the accumulation of Cu in castor. Our results demonstrated that S application was effective at promoting castor growth by reducing the bioavailability and uptake of Cu in Cu-contaminated mine tailings.
土壤中硫（S）的生物地球化学循环对重金属的生物有效性有重要影响，并影响受重金属污染土壤的利用。此外，含 S 的化合物参与重金属解毒。本研究探讨了 S 对污染矿山尾矿中生长的蓖麻（Ricinus communis L.）中铜（Cu）毒性和生物有效性的影响。结果表明，S 的施用降低了蓖麻对 Cu 的积累，促进了其生长。与对照植株相比，S 的添加使蓖麻叶片中的丙二醛（MDA）含量显著降低，表明氧化应激得到缓解。超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性以及谷胱甘肽（GSH）含量随着氧化应激的缓解而显著降低。Cu 形态的连续提取表明，S 的施用显著降低了可还原 Cu 分数，增加了可氧化 Cu 分数。它还增加了土壤中残留的 Cu 分数。化学形态的转化降低了土壤中 Cu 的生物有效性，从而降低了蓖麻对 Cu 的积累。我们的结果表明，S 的施用通过降低 Cu 污染矿山尾矿中 Cu 的生物有效性和吸收，有效促进了蓖麻的生长。
