Key Laboratory of Land Surface Pattern and Simulation, Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
Key Laboratory of Land Surface Pattern and Simulation, Beijing Key Laboratory of Environmental Damage Assessment and Remediation, Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; Beijing General Research Institute of Mining & Metallurgy Technology Group, Beijing, 100160, China.
Environ Pollut. 2021 Sep 15;285:117250. doi: 10.1016/j.envpol.2021.117250. Epub 2021 Apr 29.
Interactive effects of inorganic arsenic (As) species and polycyclic aromatic hydrocarbons (PAHs) on their uptake, accumulation and translocation in the hyperaccumulator Pteris vittata L. (P. vittata) were studied hydroponically. The presence of PAHs hindered As uptake and acropetal translocation by P. vittata, decreasing As concentrations by 29.8%-54.5% in pinnae, regardless of the initial As speciation. The inhibitive effect of PAHs was 1.6-8.7 times greater for arsenite [As(III)] than for arsenate [As(V)]. Similarly, inorganic As inhibited the uptake of fluorene (FLU) and benzo[a]pyrene (BaP) by P. vittata roots by 0.4%-21.7% and by 33.1%-69.7%, respectively. Interestingly, coexposure to As and PAHs slightly enhanced the translocation of PAHs by P. vittata with their concentrations increased 0.3 to 0.8 times in shoots, except for the As(III)+BaP treatment. The antagonistic interaction between As and PAHs uptake is likely caused by competitive inhibition or oxidative stress injury. By using synchrotron radiation micro X-ray fluorescence imaging, high concentrations of As were found distributed throughout the microstructures far from main vein of the pinnae when coexposed with PAHs, the opposite of what was observed with exposure to As only. PAHs could also significantly inhibit the accumulation and distribution of As in vascular bundles in rachis treated with As(III). The results of two-photon laser scanning confocal microscopy revealed that PAHs were mainly distributed in the vascular cylinder, epidermal cells, vascular bundles, epidermis and vein tissues, and this was independent of As speciation and treatment. This work offers new positive evidence for the interaction between As and PAHs in P. vittata, presents new information on the underlying mechanisms for interactions of As and PAHs affecting their uptake and translocation within P. vittata L., and provides direction for future research on the mechanisms of PAHs uptake by plants.
采用水培法研究了无机砷（As）形态和多环芳烃（PAHs）对蜈蚣草（Pteris vittata L.，P. vittata）吸收、积累和转运的交互作用。PAHs 的存在阻碍了蜈蚣草对 As 的吸收和向顶转运，使羽叶中 As 浓度降低 29.8%至 54.5%，而与初始 As 形态无关。对于亚砷酸盐[As(III)]，PAHs 的抑制作用比砷酸盐[As(V)]强 1.6 至 8.7 倍。同样，无机 As 抑制了 P. vittata 根系对芴（FLU）和苯并[a]芘（BaP）的吸收，分别降低了 0.4%至 21.7%和 33.1%至 69.7%。有趣的是，As 和 PAHs 共暴露时，除了 As(III)+BaP 处理外，略微增加了 PAHs 在 P. vittata 中的转运，使茎叶中 PAHs 浓度增加 0.3 至 0.8 倍。As 和 PAHs 吸收之间的拮抗相互作用可能是由于竞争抑制或氧化应激损伤引起的。通过使用同步辐射微 X 射线荧光成像，发现当与 PAHs 共暴露时，高浓度的 As 分布在远离羽叶主脉的微观结构中，与单独暴露于 As 时的情况相反。PAHs 还可以显著抑制 As(III)处理的中脉韧皮部中 As 的积累和分布。双光子激光扫描共聚焦显微镜的结果表明，PAHs 主要分布在维管束、表皮细胞、维管束、表皮和叶脉组织中，这与 As 形态和处理无关。这项工作为蜈蚣草中 As 和 PAHs 之间的相互作用提供了新的积极证据，为 As 和 PAHs 相互作用影响其在蜈蚣草 L.中的吸收和转运的潜在机制提供了新的信息，并为植物吸收 PAHs 的机制的进一步研究提供了方向。
