In Vivo Analytical Technique Revealed the Mechanism of Metabolic Dysregulation in Plants under Carbamate Pollution

　　The research team of Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center Guangzhou), in cooperation with Sun Yat-sen University and Jiangxi Normal University, developed a new solid-phase microextraction (SPME) in vivo analysis technique based on a nitrogen-rich porous polyaminal. The technique was used to track the bioaccumulation and elimination of carbamates and their metabolites, as well as the endogenous metabolic dysregulation behavior, in living Chinese cabbage plants. This contribution provided new and important information regarding exogenous carbamate contamination and related metabolic dysregulation in plants.

　　For improving agricultural productivity and protecting human and animal health from insect-vector-mediated diseases, carbamate insecticides (e.g., isoprocarb, carbofuran, and carbaryl) are used. The potential health risks and adverse impacts of carbamate insecticides are attracting considerable attention. Contaminated foods, particularly fresh vegetables, are the major insecticide receptors and source of carbamates for non-occupational exposure. Moreover, detoxification processes in plants occur under contamination exposure, thus influencing plant endogenous metabolism and nutritional composition. The simultaneous investigation of metabolic dysregulation in plants related to contamination exposure and tracking of the contaminant bioaccumulation and transformation benefits exploration of the adverse ecological implications of harmful chemicals. Unfortunately, for edible plants, previously studies mostly focused on total insecticide concentrations. Most metabolic toxicity-related research has been restricted to the post-harvest analysis of collected tissue samples from different individual plants at different sampling times using tediously exhaustive extraction methods, which would lead to the loss and disruption of unstable and short-lived endogenous substances.

　　Therefore, in this study, a SPME in vivo sampling fiber with high-coverage capture capacity based on a nitrogen-rich porous polyaminal was developed. The proposed SPME fiber was applied to the comprehensive risk assessment of carbamates in plants, thus involving three aspects: (1) monitoring of the bioaccumulation and biological elimination of carbamate insecticides in plants after exposure, (2) identification and tracking of carbamate metabolites in plants, and (3) investigation of how carbamate exposure affects the endogenous metabolome and nutritional structures of the plants. Statistical differences in the endogenous plant metabolome occurred on day three of carbamate exposure. In the exposed group, the plant metabolic alterations weren’t reversed after 5 days of contaminant free growth, although most contaminates had been eliminated. Particularly, the contents of the glucosinolate-related metabolites demonstrated significant time-dependent dysregulations.

Figure. Development of a SPME in vivo analysis method and its application in the study of plant metabolic dysregulation behavior

　　This study demonstrated that the proposed in vivo SPME fiber simultaneously offered real-time quantification of carbamates and their metabolites and metabolic dysregulation related to carbamate exposure in living plants, thus providing valuable insight on research concerning biotoxicity evaluation and risk assessment of harmful chemicals. The findings in this study were published in the journal “Environmental Science & Technology”, an international nature index journal in the environmental science field. Institute of Analysis, Guangdong Academy of Sciences (China National Analytical Center Guangzhou) is the first and corresponding author institution. Dr. Shuqin Liu is the first author of this paper. This study was supported by the projects of the National Natural Science Foundation of China, the Natural Science Foundation of Guangdong Province, the Guangdong Provincial Key R&D Programme and the Science and Technology Program of Guangzhou.

　　Paper information:

　　Shuqin Liu, Yiquan Huang, Jian Liu, Chao Chen, Gangfeng Ouyang. In vivo contaminant monitoring and metabolomic profiling in plants exposed to carbamates via a novel microextraction fiber. Environmental Science & Technology, 2021, 55(18), 12449-12458. https://pubs.acs.org/doi/10.1021/acs.est.1c04368