Insights into the uptake, accumulation, and metabolism of UV-328 in lettuce (Lactuca sativa L.) and radish (Raphanus sativus L.)

Abstract

2-(2H-benzotriazole-2yl)-4,6-di-t-pentylphenol (UV-328), a newly listed persistent organic pollutant (POP) under the Stockholm Convention, has garnered significant attention. It is imperative to understand the uptake, translocation and metabolic pathways of UV-328 in plants to assess its bioaccumulation capacity and potential human health risks. In this study, the absorption, accumulation, and metabolic characteristics of UV-328 in lettuce (Lactuca sativa L.) and radish (Raphanus sativus L.) were assessed by hydroponic experiments. In the hydroponics experiment, UV-328 was significantly absorbed by the roots of the plants, with average root concentration factors (RCFs) ranging from 58.5 to 400 mL/g for lettuce and 84.4–154 mL/g for radish. However, UV-328 was poorly translocated from roots to shoots, with a translocation factor (TF) below 0.055. Furthermore, UV-328 underwent transformation and metabolism within the plant. Utilizing a nontarget screening strategy, fourteen phase I metabolites of UV-328 were firstly identified. The metabolic pathways of UV-328 in plants including hydroxylation, demethylation, oxidation, acetylation and deoxygenation were also suggested. It was worth noting that UV-328 has a significant adverse impact on plant growth and quality. The concentration of chlorophyll in plants exposed to UV-328 was significantly reduced, as were the concentrations of water, flavonoids, vitamin C and amino acids.