Research progress in three-phase metabolic transformations of pesticides in plants mediated by enzymes

The metabolic transformations of pesticides in plants induced by plant enzymes are crucial for their application safety and risk assessment. Existing studies demosntrated that the metabolic pathways of pesticides in plants were mainly divided into three stages. Phase I reactions include oxidation, hydrolysis, reduction and other processes, which were either catalysed by enzymes or were abiotic degradation processes. Phase II reactions were conjugation reactions between pesticides and/or their metabolites with endogenous substances in the plant via the action of glutathione S-transferases, glycosyltransferases, malonyltransferases, and etc. In Phase III metabolism, the conjugates were secreted from cytosol into the vacuole or apoplast in plant, which were stored as a solutes or bound residues. In this review, the recent progress in the three-phase metabolic transformations of pesticides in plants, which is mediated by plant enzymes, has been summaried. And also covers plant enzymes involed in the metabolic processes, gene identification, metabolic pathways and regulatory mechanisms, and both the research methods and research applications were reviewed. This paper will provide theoretical and technical references for relevant research for analyzing the fate of pesticides in plant, dietary risk assessment of pesticides, resistance management of pesticide and environmental remediation.