Department of Municipal and Environmental Engineering, Beijing Jiaotong University, Beijing, 100044, China; Laboratory of Quality and Safety Risk Assessments for Agro-products on Environmental Factors (Beijing), Ministry of Agriculture and Rural Affairs, 100029, China.
Laboratory of Quality and Safety Risk Assessments for Agro-products on Environmental Factors (Beijing), Ministry of Agriculture and Rural Affairs, 100029, China; Beijing Municipal Station of Agro-Environmental Monitoring, 100029, China.
Environ Pollut. 2021 Sep 15;285:117246. doi: 10.1016/j.envpol.2021.117246. Epub 2021 Apr 29.
Perfluorooctanoic acid (PFOA) is a typical persistent organic pollutant commonly detected in ecosystem. Insights into the risks of PFOA in crops, from the perspectives of food nutritional compositions, are sparse. In this study, the physiological responses to PFOA induced oxidative stress were investigated in lettuce (Lactuca sativa) leaves hydroponically exposed to 5 and 50 μg/L PFOA. The effects on photosynthesis and nutritional compositions were characterized. 35.1 and 316.7 ng/g dry weight PFOA were bio-accumulated in lettuce leaves under exposure to 5 and 50 μg/L PFOA, respectively. PFOA led to exposure-dependent over-generation of reactive oxidative species (ROS; HO, 8.1%-38.7%; OH, 11.3%-26.4%; O, 3.1%-22.8%) in leaves. Both non-enzymatic and enzymatic antioxidants were activated to scavenge ROS. Nevertheless, metabolomics results indicated some nutritional compositions in lettuce leaves were elevated by environmentally relevant concentrations of PFOA. Both primary metabolites, such as carbohydrates in the tricarboxylic acid cycle and amino acids, and secondary metabolites, such as bioactive (poly)phenol and alkaloid compounds, were significantly up-regulated. Leaf net photosynthetic rates were stimulated and intercellular CO concentration was decreased. A thorough scheme on the interaction between PFOA and lettuce leaves was proposed as well, to enhance the understanding of PFOA risks in crops.
全氟辛酸 (PFOA) 是一种典型的持久性有机污染物，通常在生态系统中检测到。从食物营养成分的角度来看，关于 PFOA 在作物中的风险的认识还很匮乏。在这项研究中，研究了在水培条件下生菜叶片暴露于 5 和 50μg/L PFOA 时，PFOA 诱导的氧化应激的生理反应。并对光合作用和营养成分的影响进行了研究。在暴露于 5 和 50μg/L PFOA 下，生菜叶片中分别积累了 35.1 和 316.7ng/g 干重的 PFOA。PFOA 导致叶片中活性氧（ROS；HO，8.1%-38.7%；OH，11.3%-26.4%；O，3.1%-22.8%）的产生与暴露程度相关。非酶和酶抗氧化剂都被激活以清除 ROS。然而，代谢组学结果表明，环境相关浓度的 PFOA 会导致生菜叶片中的一些营养成分升高。包括三羧酸循环中的碳水化合物和氨基酸等初级代谢物，以及生物活性（多）酚和生物碱等次级代谢物，都被显著上调。叶片净光合速率被刺激，细胞间 CO2 浓度降低。此外，还提出了一个关于 PFOA 与生菜叶片相互作用的综合方案，以增强对作物中 PFOA 风险的理解。
