Department of Biochemistry, Delta State University, Abraka, Nigeria.
Environ Sci Pollut Res Int. 2017 Oct;24(30):23735-23743. doi: 10.1007/s11356-017-9988-z. Epub 2017 Sep 1.
The present study aims to assess the effects of the two kinds of farmyard manure (poultry and pig manures) as amendments for soil on cadmium (Cd) toxicity in plants using cowpea seedlings as plant model. Cd toxicity was evaluated by assessing the effect of the metal on the growth rate and antioxidant status as well as the ability of the plant to metabolise xenobiotic. There was a significantly (p < 0.05) increased concentration of Cd in the root, stem and leaves of cowpea seedlings grown in all the treated soils relative to control. Addition of poultry manure to the soil significantly (p < 0.05) decreased the level of Cd in these component parts of the seedlings and their corresponding bioaccumulation factor in a dose-dependent manner as compared with treatments with Cd pollution without manure addition and Cd pollution with pig manure addition. There was restoration of Cd-induced effect on growth rate parameters to levels comparable to controls in cowpea seedlings grown in Cd-treated soil augmented with poultry manure but not in cowpea seedlings in cadmium-treated soil with pig manure amendments. Similarly, augmentation of Cd-treated soil with pig manure did not alter the Cd-induced effect on the levels of superoxide dismutase (SOD) and lipid peroxidation (LPO) in leaf, stem and roots, as SOD remained significantly (p < 0.05) decreased and LPO increased relative to control. On the other hand, the levels of SOD and LPO in these parts of cowpea seedlings grown in Cd-treated soils amended with poultry manure were restored to a level not significantly (p > 0.05) different from control. Like in the case of SOD, the Cd-induced inhibition of the activity of xenobiotic metabolising enzymes, aldehyde oxidase and sulphite oxidase remained significantly (p < 0.05) decreased in the organs of seedling grown in Cd-treated soil amended with pig manure. Conversely, the Cd-induced effect on the activities of these enzymes was reversed in the organs of seedlings exposed to Cd and poultry manure as it was not significantly (p > 0.05) different from control. In conclusion, the findings of the study revealed that supplementation of Cd-treated soils with pig and poultry manures reversed effects of Cd on cowpea seedlings. However, poultry manure was more effective than pig manure in ameliorating the effects of Cd.
本研究旨在评估两种厩肥（禽粪和猪粪）作为土壤改良剂对植物中镉（Cd）毒性的影响，采用豇豆幼苗作为植物模型。通过评估金属对生长速度和抗氧化状态的影响以及植物代谢外来物质的能力来评价 Cd 毒性。与对照相比，在所有处理过的土壤中生长的豇豆幼苗的根、茎和叶中的 Cd 浓度显著增加（p<0.05）。与不加禽粪的 Cd 污染处理和加猪粪的 Cd 污染处理相比，向土壤中添加禽粪可显著降低（p<0.05）幼苗各部分及相应生物富集因子中的 Cd 浓度，呈剂量依赖性。在添加禽粪的 Cd 处理土壤中生长的豇豆幼苗中，Cd 诱导的生长速率参数的恢复到与对照相当的水平，但在添加猪粪的 Cd 处理土壤中生长的豇豆幼苗中则没有。同样，向 Cd 处理土壤中添加猪粪并不能改变 Cd 对叶片、茎和根中超氧化物歧化酶（SOD）和脂质过氧化（LPO）水平的诱导作用，SOD 仍显著降低（p<0.05），而 LPO 则升高，与对照相比。另一方面，在添加禽粪的 Cd 处理土壤中生长的豇豆幼苗各部分的 SOD 和 LPO 水平恢复到与对照无显著差异（p>0.05）的水平。与 SOD 一样，在添加猪粪的 Cd 处理土壤中生长的幼苗器官中，外源物质代谢酶醛氧化酶和亚硫酸盐氧化酶的活性也受到 Cd 诱导的抑制，仍显著降低（p<0.05）。相反，在添加 Cd 和禽粪的幼苗器官中，Cd 对这些酶活性的诱导作用被逆转，与对照相比无显著差异（p>0.05）。综上所述，研究结果表明，向 Cd 处理土壤中添加猪粪和禽粪可逆转 Cd 对豇豆幼苗的影响。然而，禽粪在改善 Cd 影响方面比猪粪更有效。
