摘要
Perfluoroether Carboxylic Acids (PFECAs), which are substitutes for perfluorooctanoic acid (PFOA), have been widely detected in various environmental matrices. PFECAs exhibit higher accumulation in plant leaves. Spatial heterogeneity of many contaminants in leaves can lead to varied ecological risks. However, the distribution patterns and metabolic impacts of PFECAs remain poorly understood in plants. In this study, an integrated approach employing desorption electrospray ionization mass spectrometry imaging (DESI-MSI), transcriptomics, metabolomics and molecular docking was used to investigate the spatially resolved distribution and metabolic effects of two PFECAs (HFPO-DA and HFPO-TA) in wheat. PFECAs, especially HFPO-DA, were observed to accumulate predominantly in the leaf margins. Significant spatial variations in gene expression and metabolite profiles were identified between the inner and outer regions of leaves. Notably, genes associated with photosynthesis were significantly downregulated in the leaf margins compared to the central tissue. Exposure to PFECAs also resulted in decreased chlorophyll content in leaves. Differentially expressed metabolites (DEMs) and genes (DEGs) associated with oxidative stress were observed to exhibit abnormal regulation at the leaf margins. Molecular docking simulations revealed that PFECAs preferentially bound to key proteins, such as ferredoxin-NADP+ reductase (FNR) in the photosynthetic electron transport chains and protoporphyrinogen oxidase (PPO) in chlorophyll biosynthesis. These interactions likely disrupted photosynthetic function and chlorophyll synthesis, ultimately contributing to leaf yellowing in the leaf margins. These findings provide important insights into the spatially explicit toxicological mechanisms of PFECAs in wheat and establish a foundation for future research on spatial toxicology of PFAS in plants.
危险品化学品经营许可证（带存储）