College of Environmental Science, Sichuan Agricultural University, Chengdu, 611130, China; Soil and Water Sciences Department, University of Florida, Gainesville, FL, 32611, USA.
Soil and Water Sciences Department, University of Florida, Gainesville, FL, 32611, USA.
Environ Pollut. 2022 May 1;300:118982. doi: 10.1016/j.envpol.2022.118982. Epub 2022 Feb 9.
Arsenic (As) and copper (Cu) are common co-contaminates in soils. However, their interactive effects on their accumulation and distribution in As-hyperaccumulator Pteris vittata are poorly understood. A hydroponic experiment was conducted with As being 0, 5, or 50 μM and Cu being 0.32, 3.2, or 32 μM to evaluate their phytotoxicity, accumulation, and distribution in P. vittata. In addition, As and Cu uptake kinetics were examined using the Michaelis-Menten kinetics model. Total As and Cu concentrations in P. vittata were up to 487 and 1355 mg kg. About 39-81% of the As was in the fronds compared to 0.6-18% for Cu. At 50 μM As, increasing Cu concentration from 0.32 to 32 μM increased root As while decreasing frond As concentrations, with the translocation factor (ratio of As in fronds to roots) being reduced from 4.0 to 0.31. In contrast, As did not affect Cu accumulation in P. vittata. Michaelis constant K value for As was higher than that of Cu (6.49-24.9 vs. 0.43-3.36), consistent with higher Cu uptake than As. Besides, Cu reduced root K but increased P levels in the roots, whereas As increased the K and P concentrations in the fronds. Our results suggest that P. vittata accumulated more Cu than As in the roots, contributing to its low As translocation. As such, high levels of Cu are likely to reduce As uptake by P. vittata during phytoremediation of As-contaminated sites.
砷（As）和铜（Cu）是土壤中常见的共污染物。然而，它们对砷超富集植物蜈蚣草中砷和铜的积累和分布的相互影响知之甚少。本研究采用水培实验，设置 As 为 0、5 或 50 μM 和 Cu 为 0.32、3.2 或 32 μM，以评估其对蜈蚣草的毒性、积累和分布的影响。此外，还采用米氏动力学模型研究了 As 和 Cu 的吸收动力学。蜈蚣草中总 As 和 Cu 的浓度最高分别可达 487 和 1355 mg kg。与 Cu（0.6-18%）相比，As 中约有 39-81%位于叶片中。在 50 μM As 条件下，Cu 浓度从 0.32 μM 增加到 32 μM 时，根部 As 增加而叶片 As 减少，转运因子（叶片中 As 与根部中 As 的比值）从 4.0 降低到 0.31。相反，As 并不影响蜈蚣草对 Cu 的积累。As 的米氏常数 K 值高于 Cu（6.49-24.9 比 0.43-3.36），表明 Cu 的吸收高于 As。此外，Cu 降低了根部的 K，但增加了根部的 P 水平，而 As 则增加了叶片的 K 和 P 浓度。研究结果表明，蜈蚣草根中积累的 Cu 多于 As，这有助于降低其 As 的转运。因此，在砷污染场地的植物修复过程中，高浓度的 Cu 可能会降低蜈蚣草对 As 的吸收。
