College of Land Science and Technology, China Agricultural University, Beijing. China; Department of Environmental Sciences and Engineering, Government College University Faisalabad, Pakistan.
Department of Botany, Government College University Faisalabad, Pakistan.
Sci Total Environ. 2020 May 15;717:137086. doi: 10.1016/j.scitotenv.2020.137086. Epub 2020 Feb 5.
Co-contamination of soils with cadmium (Cd) and arsenic (As) in rice growing areas is a serious threat to environment and human health. Increase in soil Cd and As levels curtail the growth and development of rice plants by causing oxidative stress and reduction in photosynthetic activity. Therefore, it is necessary to formulate and evaluate different strategies for minimizing the Cd and As uptake in rice plant. We modified biochar (BC) with goethite and assessed the effects of goethite-modified biochar (GB) application on mitigating Cd and As stress in rice plant. Although BC supply to rice plants enhanced their performance in contaminated soil but application of different GB levels i.e.1.5% GB to the soil resulted in prominent improvements in physiological and biochemical attributes of rice plants grown in Cd and As co-contaminated paddy soil. It was observed that soil amendment with GB increased the plant growth, biomass, photosynthetic pigments, gas exchange attribute of rice plant and suppressed the oxidative stress in rice leaves and roots by increased antioxidant enzymes activities. Supplementing the soil with 1.5% GB incremented the iron plaque (Fe-plaque) formation and enhanced the Cd and As sequestration by Fe-plaque. Application of GB (1.5%) significantly improved the Fe content of Fe-plaque by 68.7%. Maximum Cd (1.57 mg kg) and As (0.85 mg kg) sequestration by Fe-plaque was observed with 1.5% GB treatment. Compared to the control, 1.5% GB treatment application prominently reduced the Cd content in the rice roots and shoots by 42.9%, and 56.7%, respectively and As content in the rice roots and shoots declined by 32.2%, 46.6%, respectively, compared to the control. These findings demonstrate that amending the soil with 1.5% GB can be a potential remediation strategy for checking Cd and As accumulation, reducing oxidative stress and increasing the growth of rice plant.
在水稻种植区，土壤中镉（Cd）和砷（As）的共污染对环境和人类健康构成了严重威胁。土壤中 Cd 和 As 水平的升高通过引起氧化应激和降低光合作用活性来抑制水稻植株的生长和发育。因此，有必要制定和评估不同的策略，以最大限度地减少水稻植株对 Cd 和 As 的吸收。我们用针铁矿对生物炭（BC）进行了改性，并评估了针铁矿改性生物炭（GB）的应用对减轻水稻植株 Cd 和 As 胁迫的影响。尽管向水稻植株提供 BC 会增强其在污染土壤中的性能，但向土壤中添加不同水平的 GB，即 1.5% GB，可显著改善在 Cd 和 As 共污染稻田土壤中生长的水稻的生理和生化特性。结果表明，土壤添加 GB 增加了植株的生长、生物量、光合色素、气体交换特性，抑制了水稻叶片和根系的氧化应激，通过增加抗氧化酶的活性。向土壤中添加 1.5% GB 增加了铁斑（Fe-plaque）的形成，并通过 Fe-plaque 增强了 Cd 和 As 的固定。GB（1.5%）的应用显著提高了 Fe-plaque 中铁的含量，提高了 68.7%。用 1.5% GB 处理观察到 Fe-plaque 对 Cd（1.57 mg kg）和 As（0.85 mg kg）的最大固定。与对照相比，1.5% GB 处理显著降低了水稻根系和地上部分 Cd 含量分别为 42.9%和 56.7%，根系和地上部分 As 含量分别降低了 32.2%和 46.6%。这些发现表明，用 1.5% GB 改良土壤是一种减少 Cd 和 As 积累、减轻氧化应激和增加水稻生长的潜在修复策略。
