New insight into phytometabolism and phytotoxicity mechanism of widespread plasticizer di (2-ethylhexyl) phthalate in rice plants

Xiaolong Yu; Huanhuan Xing; Jianteng Sun; Xiaodong Du; Guining Lu; Lizhong Zhu

doi:10.1016/j.scitotenv.2023.163254

New insight into phytometabolism and phytotoxicity mechanism of widespread plasticizer di (2-ethylhexyl) phthalate in rice plants

Sci Total Environ. 2023 Jul 1:880:163254. doi: 10.1016/j.scitotenv.2023.163254. Epub 2023 Apr 3.

Authors

Xiaolong Yu¹, Huanhuan Xing², Jianteng Sun³, Xiaodong Du⁴, Guining Lu⁴, Lizhong Zhu⁵

Affiliations

¹ Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China.
² Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China; School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China.
³ Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China. Electronic address: sunjianteng@zju.edu.cn.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, China.
⁵ Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310058, China.

PMID: 37019237
DOI: 10.1016/j.scitotenv.2023.163254

Abstract

Di-(2-ethylhexyl) phthalate (DEHP) as widely utilized plasticizer has aroused increasing concerns since its endocrine disrupting effects and continuous accumulation in biota. To date, the interaction mechanism between DEHP and rice plants has not been clearly illustrated at molecular level. Here, we investigated biological transformation and response of rice plants (Oryza sativa L.) to DEHP at realistic exposure concentrations. Nontargeted screening by UPLC-QTOF-MS was used to verify 21 transformation products derived from phase I metabolism (hydroxylation and hydrolysis) and phase II metabolism (conjugation with amino acids, glutathione, and carbohydrates) in rice. MEHHP-asp, MEHHP-tyr, MEHHP-ala, MECPP-tyr and MEOHP-tyr as the conjugation products with amino acids are observed for the first time. Transcriptomics analyses unraveled that DEHP exposure had strong negative effects on genes associated with antioxidative components synthesis, DNA binding, nucleotide excision repair, intracellular homeostasis, and anabolism. Untargeted metabolomics revealed that metabolic network reprogramming in rice roots was induced by DEHP, including nucleotide metabolism, carbohydrate metabolism, amino acid synthesis, lipid metabolism, synthesis of antioxidant component, organic acid metabolism and phenylpropanoid biosynthesis. The integrated analyses of interaction between differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) endorsed that metabolic network regulated by DEGs was significantly interfered by DEHP, resulting in cell dysfunction of roots and visible growth inhibition. Overall, these finding generated fresh perspective for crops security caused by plasticizer pollution and enhanced the public focus on dietary risk.

Keywords: Di-(2-ethylhexyl) phthalate; Metabolic network; Pathways enrichment; Transcriptomics; Transformation products.

MeSH terms

Diethylhexyl Phthalate* / metabolism
Diethylhexyl Phthalate* / toxicity
Oryza* / metabolism
Phthalic Acids* / analysis
Plasticizers / toxicity

Substances

phthalic acid
Plasticizers
Diethylhexyl Phthalate
Phthalic Acids