Botany Department, Faculty of Science, Zagazig University, Zagazig 44519, Egypt.
Botany Department, Faculty of Science, Zagazig University, Zagazig 44519, Egypt.
Ecotoxicol Environ Saf. 2018 Nov 30;164:704-712. doi: 10.1016/j.ecoenv.2018.08.088. Epub 2018 Aug 29.
The tolerance and antioxidant response of the green alga P. pringsheimii to cadmium (Cd) and lead (Pb) was investigated. The algal biomass was constant at the relatively lower metal concentrations of Cd and Pb (5, 12 µM, and 2.5-200 µM, respectively), whereas higher concentrations severely inhibited the algal biomass yield. The pigment content of P. pringsheimii decreased due to the investigated metals, especially with Cd concentrations. However, the Pb concentrations of 2.5-200 µM enhanced the pigment content. The carotenoids content was highly repressed by the Cd concentrations. Nevertheless, Pb concentrations highly stimulated the carotenoids content, with the exception of 400 and 500 µM Pb. The biochemical contents of P. pringsheimii including phenolic, total soluble protein and carbohydrate contents responded variably to the investigated metals. The concentrations of Cd were found to be harmful to total soluble protein and carbohydrates, but not the phenolic contents. However, all biochemical contents were stimulated under relatively lower Pb concentrations. Markedly for Pb, the radical scavenging, reducing power, and chelating activities improved under the metals exposure excluding higher concentrations. The activities of the antioxidant enzymes (SOD, CAT, and POD) were highly stimulated with all treatments (except for CAT activities at the highest Cd and Pb concentrations, 300 and 500 µM, respectively). Remarkably, Cd treatments have higher antioxidant enzyme activities compared to that of Pb treatments. The antioxidants augmentation of P. pringsheimii under the metal stress may be exploited for future application in several fields.
研究了绿藻 P. pringsheimii 对镉（Cd）和铅（Pb）的耐受性和抗氧化响应。在相对较低的金属浓度 Cd 和 Pb（分别为 5、12 µM 和 2.5-200 µM）下，藻生物质保持不变，而较高浓度则严重抑制藻生物质产量。由于所研究的金属，特别是 Cd 浓度，P. pringsheimii 的色素含量下降。然而，2.5-200 µM 的 Pb 浓度增加了色素含量。类胡萝卜素含量受到 Cd 浓度的强烈抑制。然而，除了 400 和 500 µM 的 Pb 之外，Pb 浓度强烈刺激类胡萝卜素含量。P. pringsheimii 的生化含量包括酚类、总可溶性蛋白和碳水化合物含量对所研究的金属表现出不同的反应。发现 Cd 浓度对总可溶性蛋白和碳水化合物有害，但对酚类含量无害。然而，所有生化含量在相对较低的 Pb 浓度下均受到刺激。值得注意的是，除了较高浓度（分别为 300 和 500 µM 的 Cd 和 Pb）外，自由基清除、还原能力和螯合活性在金属暴露下得到改善。所有处理（除最高 Cd 和 Pb 浓度，300 和 500 µM 时的 CAT 活性外）均高度刺激抗氧化酶（SOD、CAT 和 POD）的活性。值得注意的是，Cd 处理的抗氧化酶活性高于 Pb 处理。在金属胁迫下 P. pringsheimii 的抗氧化剂增加可能会在未来应用于多个领域。
