School of Geographic Sciences, East China Normal University, Shanghai 200241, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai Jiao Tong University, Shanghai 200240, China.
J Hazard Mater. 2022 Mar 15;426:127831. doi: 10.1016/j.jhazmat.2021.127831. Epub 2021 Nov 26.
The industrial and agricultural applications of rare earth elements (REEs) lead to considerable REE emissions into environment. Yet, little is known about the molecular-level effects and interactions of REEs in terrestrial plants. Herein, the individual and joint effects of La and Ce in Triticum aestivum were investigated using mass spectrometry-based metabolomics. Metabolic effect level index (MELI) was utilized as a readable endpoint for quantifying mixture interactions. Exposure to single La/Ce at environmentally relevant levels induced significant dose-dependent metabolic changes. The highly overlap of differential metabolites and perturbed pathways of La and Ce suggested their similar mode of action. Exposure to La-Ce mixtures did not induce additional metabolic pathway perturbation. Specifically, metabolism of amino sugar and nucleotide sugar, starch and sucrose, fructose and mannose, glycerophospholipid and purine were disrupted for both single and binary exposures. These results, together with physiological indicators, point to REE-induced oxidative stress, energy expenditure, DNA damage and membrane disturbance. The MELI calculations showed that La and Ce interacted synergistically at the overall metabolic level, which could be causally linked to synergistic interaction at the individual level (root elongation). This work proved metabolomics could be an important and effective strategy for interpreting toxicity and interactions of REE mixtures.
稀土元素（REEs）在工业和农业中的应用导致大量 REE 排放到环境中。然而，人们对 REE 在陆地植物中的分子水平效应和相互作用知之甚少。在此，使用基于质谱的代谢组学研究了 La 和 Ce 在小麦中的单独和联合作用。代谢效应水平指数（MELI）被用作量化混合物相互作用的可读终点。在环境相关水平下暴露于单一 La/Ce 会引起显著的剂量依赖性代谢变化。La 和 Ce 的差异代谢物和受干扰的途径高度重叠，表明它们具有相似的作用模式。暴露于 La-Ce 混合物不会引起额外的代谢途径扰动。具体而言，对于单一和二元暴露，氨基酸糖和核苷酸糖、淀粉和蔗糖、果糖和甘露糖、甘油磷脂和嘌呤的代谢都被打乱。这些结果连同生理指标表明，REE 会引起氧化应激、能量消耗、DNA 损伤和膜扰动。MELI 计算表明，La 和 Ce 在整体代谢水平上协同相互作用，这可能与个体水平（根伸长）的协同相互作用有关。这项工作证明了代谢组学可以成为解释 REE 混合物毒性和相互作用的重要和有效策略。
