Zhao Rui, Ren Wenjie, Wang Huimin, Li Zhenxuan, Teng Ying, Luo Yongming
Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Nanjing University of Information Science & Technology, Nanjing 210044, China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2022 Dec 15;852:158405. doi: 10.1016/j.scitotenv.2022.158405. Epub 2022 Sep 1.
Carbon nanotubes have displayed great potential in enhancing phytoremediation of PAHs polluted soils. However, the response of plants to the coexistence of carbon nanotubes and PAHs and the associated influencing mechanisms remain largely unknown. Here, the effect of carbon nanotubes on alfalfa growth and pyrene uptake under exposure to pyrene was evaluated through sand culture experiment and gas chromatography time-of-flight mass spectrometer (GC-TOF-MS) based metabolomics. Results showed that pyrene at 10 mg kg obviously reduced the shoot fresh weight of alfalfa by 18.3 %. Multiwall carbon nanotubes (MWCNTs) at 25 and 50 mg kg significantly enhanced the shoot fresh weight in a dose-dependent manner, nearly by 80 % at 50 mg kg. Pyrene was mainly accumulated in alfalfa roots, in which the concentration was 35 times as much as that in shoots. MWCNTs greatly enhanced the accumulation of pyrene in alfalfa roots, almost by two times at 50 mg kg, while decreased pyrene concentration in shoots, from 0.11 mg kg to 0.044 mg kg at MWCNTs concentration of 50 mg kg. Metabolomics data revealed that pyrene at 10 mg kg trigged significant metabolic changes in alfalfa root exudates, downregulating 27 metabolites. MWCNTs generated an increase in the contents of some downregulated metabolites caused by pyrene stress, which were restored to the original level or even higher, mainly including organic acids and amino acids. MWNCTs significantly enriched some metabolic pathways positively correlated with shoot growth and pyrene accumulation in shoots under exposure to pyrene, including TCA cycle, glyoxylate and dicarboxylate metabolism, cysteine and methione metabolism as well as alanine, aspartate and glutamate metabolism. This work highlights the regulation effect of MWCNTs on the metabolism of root exudates, which are helpful for alfalfa to alleviate the stress from pyrene contamination.
碳纳米管在增强多环芳烃污染土壤的植物修复方面已展现出巨大潜力。然而，植物对碳纳米管与多环芳烃共存的响应及相关影响机制仍 largely 未知。在此，通过砂培实验和基于气相色谱 - 飞行时间质谱（GC - TOF - MS）的代谢组学评估了碳纳米管对暴露于芘的苜蓿生长及芘吸收的影响。结果表明，10 mg/kg 的芘显著降低了苜蓿地上部鲜重 18.3%。25 和 50 mg/kg 的多壁碳纳米管（MWCNTs）以剂量依赖方式显著提高了地上部鲜重，50 mg/kg 时近提高了 80%。芘主要积累在苜蓿根部，其浓度是地上部的 35 倍。MWCNTs 极大地增强了芘在苜蓿根部的积累，50 mg/kg 时几乎增加了两倍，同时降低了地上部芘浓度，MWCNTs 浓度为 50 mg/kg 时从 0.11 mg/kg 降至 0.044 mg/kg。代谢组学数据显示，10 mg/kg 的芘引发了苜蓿根系分泌物显著的代谢变化，下调了 27 种代谢物。MWCNTs 使芘胁迫导致的一些下调代谢物含量增加，这些代谢物恢复到原始水平甚至更高，主要包括有机酸和氨基酸。MWNCTs 显著富集了一些与暴露于芘时地上部生长和地上部芘积累呈正相关的代谢途径，包括三羧酸循环、乙醛酸和二羧酸代谢、半胱氨酸和甲硫氨酸代谢以及丙氨酸、天冬氨酸和谷氨酸代谢。这项工作突出了 MWCNTs 对根系分泌物代谢的调节作用，这有助于苜蓿缓解芘污染带来的胁迫。
