elucidating-the-metabolism-of-24-dibromophenol-in-plants

Elucidating the Metabolism of 2,4-Dibromophenol in Plants

Crops can be extensively exposed to organic pollutants, since soil is a major sink for pollutants discarded into the environment. This creates potential ...

assessing-cytotoxicity-metabolites-typical-triazole-pesticides

Assessing Cytotoxicity of Metabolites of Typical Triazole Pesticides in Plants

Various organic pollutants have been released into the environment because of anthropogenic activities. These pollutants can be taken up by crop plants, ...

Zhejiang University of Technology

Freshwater cyanobacterial blooms have drawn public attention because they threaten the safety of water resources and human health worldwide. Heavy cyanobacterial blooms outbreak in Lake Taihu in summer annually and vanish in other months. To find out the factors impacting the cyanobacterial blooms, the present study measured the physicochemical parameters of water and investigated the composition of microbial community using the 16S rRNA gene and internal transcribed spacer amplicon sequencing in the months with or without bloom. The most interesting finding is that two major cyanobacteria, Planktothrix and Microcystis, dramatically alternated during a cyanobacterial bloom in 2016, which is less mentioned in previous studies. When the temperature of the water began increasing in July, Planktothrix appeared first and showed as a superior competitor for M. aeruginosa in NO-rich conditions. Microcystis became the dominant genus when the water temperature increased further in August. Laboratory experiments confirmed the influence of temperature and the total dissolved nitrogen (TDN) form on the growth of Planktothrix and Microcystis in a co-culture system. Besides, species interactions between cyanobacteria and non-cyanobacterial microorganisms, especially the prokaryotes, also played a key role in the alteration of Planktothrix and Microcystis. The present study exhibited the alteration of two dominant cyanobacteria in the different bloom periods caused by the temperature, TDN forms as well as the species interactions. These results helped the better understanding of cyanobacterial blooms and the factors which contribute to them.

Alteration of dominant cyanobacteria in different bloom periods caused by abiotic factors and species interactions.

The goal of the current study was to quantify the trophic transfer of copper nanoparticles (CuNPs) in a food chain consisting of the microalga Pseudokirchneriella subcapitata as the representative of primary producer, the grazer Daphnia magna, and the omnivorous mysid Limnomysis benedeni. To quantify the size and number concentration of CuNPs in the biota, tissue extraction with tetramethylammonium hydroxide (TMAH) was performed and quantification was done by single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). The bioconcentration factor (BCF) of the test species for CuNPs varied between 10 - 10 L/kg dry weight when expressing the internal concentration on a mass basis, which was lower than BCF values reported for Cu (10 - 10 L/kg dry weight). The particle size of CuNPs determined by sp-ICP-MS ranged from 22 to 40 nm in the species. No significant changes in the particle size were measured throughout the food chain. Moreover, the measured number of CuNPs in each trophic level was in the order of 10 particles/kg wet weight. The calculated trophic transfer factor (mass concentration basis) was > 1. This indicates biomagnification of particulate Cu from P. subcapitata to L. benedeni. It was also found that the uptake of particulate Cu (based on the particle number concentration) was mainly from the dietary route rather than from direct aqueous exposure. Furthermore, dietary exposure to CuNPs had a significant effect on the feeding rate of mysid during their transfer from daphnia to mysid and from alga through daphnia to mysid. This work emphasizes the importance of tracing the particulate fraction of metal-based engineered nanoparticles when studying their uptake and trophic transfer.

Trophic transfer of Cu nanoparticles in a simulated aquatic food chain.

The ubiquitous occurrence of phthalate esters (PAEs) in agricultural soil results in their inevitable accumulation in crops, potentially increasing the risk of human exposure to PAEs via daily food intake. Dietary health risk of PAEs not only depends on locally produced food but also the imported food from other regions. However, the impact of interregional food trade on human dietary exposure to PAEs has been seldom assessed. Herein, we investigated the impact of interregional food trade on the dietary exposure to PAEs that contributed from soil contamination in China. The average daily dietary intake of PAEs for the Chinese general population was 24.3 μg/kg/day when assuming the total consumption of crops from local market only, while the average daily dietary intake of PAEs for the Chinese general population was decreased by 2.9% when the effects of interregional food trade were involved into the calculation. Additionally, the interregional food trade remarkably increased the daily dietary intake of PAEs in the regions of Beijing-Tianjin region (47.8%), North (21.4%) and Central (4.26%). As a result, the hazard quotient value of PAEs in the regions of Beijing-Tianjin region, North and Central increased by 29.4%, 11.0% and 5.0%, respectively, owing to the consumption of imported crops from the highly PAEs contaminated regions. In contrast, the daily intake and hazard quotient value of PAEs in the regions of Central Coast, Northwest, Northeast and South Coast decreased due to the interregional trade. These results indicated that the interregional food trade promoted the transfer of PAEs between regions and thus altered the potential risk to the local population. Overall, this study highlights the importance of taking the interregional food trade into account to provide a more accurate risk assessment of dietary exposure to pollutants.

Human exposure to phthalate esters in soils embodied in interregional food trade in China.

Food consumption has been considered a key pathway of bisphenol compound (BP) exposure for humans. However, there is a lack of evidence concerning their congener-specific behavior and metabolism in plants. Herein, we examined the uptake and metabolism of five BPs in plants using carrot cells. Bisphenol S (BPS) and bisphenol AF (BPAF) exhibited substantially lower dissipation rates in the cells than the other BPs, indicating a strong selectivity in the uptake and metabolism among bisphenol congeners. For a total of 23 metabolites of BPs, the predominant biotransformation pathways were found to be glycosylation, methoxylation, and conjugation, while hydroxylation, methylation, and glutathionylation were only observed for some BPs. The changes in the mRNA expression of cytochrome P450 (P450) and the activities of glycosyltransferase and glutathione S-transferase were remarkably higher in cells exposed to bisphenol F, bisphenol A, and bisphenol B than in cells exposed to BPS and BPAF, indicating congener specificity in their effects on enzymes and the associated biotransformation processes. Consequently, the potential congener-specific differences in plant uptake, metabolism, and accumulation must be considered when assessing the environmental risks posed by these commonly used plasticizers.

Congener-Specific Uptake and Metabolism of Bisphenols in Carrot Cells: Dissipation Kinetics, Biotransformation, and Enzyme Responses.

Herein, we investigated to which extent metallic nanoparticles (MNPs) affect the trophic transfer of other coexisting MNPs from lettuce to terrestrial snails and the associated tissue-specific distribution using toxicokinetic (TK) modeling and single-particle inductively coupled plasma mass spectrometry. During a period of 22 days, snails were fed with lettuce leaves that were root exposed to AgNO (0.05 mg/L), AgNPs (0.75 mg/L), TiONPs (200 mg/L), and a mixture of AgNPs and TiONPs (equivalent doses as for single NPs). The uptake rate constants () were 0.08 and 0.11 kg leaves/kg snail/d for Ag and 1.63 and 1.79 kg leaves/kg snail/d for Ti in snails fed with NPs single- and mixture-exposed lettuce, respectively. The elimination rate constants () of Ag in snails exposed to single AgNPs and mixed AgNPs were comparable to the corresponding , while the  for Ti were lower than the corresponding . As a result, single TiONP treatments as well as exposure to mixtures containing TiONPs induced significant biomagnification from lettuce to snails with kinetic trophic transfer factors (TTF) of 7.99 and 6.46. The TTF of Ag in the single AgNPs treatment (1.15 kg leaves/kg snail) was significantly greater than the TTF in the mixture treatment (0.85 kg leaves/kg snail), while the fraction of Ag remaining in the body of snails after AgNPs exposure (36%) was lower than the Ag fraction remaining after mixture exposure (50%). These results indicated that the presence of TiONPs inhibited the trophic transfer of AgNPs from lettuce to snails but enhanced the retention of AgNPs in snails. Biomagnification of AgNPs from lettuce to snails was observed in an AgNPs single treatment using AgNPs number as the dose metric, which was reflected by the particle number-based TTFs of AgNPs in snails (1.67, i.e., higher than 1). The size distribution of AgNPs was shifted across the lettuce-snail food chain. By making use of particle-specific measurements and fitting TK processes, this research provides important implications for potential risks associated with the trophic transfer of MNP mixtures.

Toxicokinetics and Particle Number-Based Trophic Transfer of a Metallic Nanoparticle Mixture in a Terrestrial Food Chain.

The extensive application of phthalate esters (PAEs) as plasticizers has raised considerable concern regarding their environmental load, but the associated occurrence of PAE metabolites has often been ignored. The soil-plant system is a vital source of human exposure to PAEs via crop intake. Here, paired soil-plant samples were collected from eastern China to investigate the occurrence characteristics of seven PAE congeners and two primary monoester phthalate metabolites (mPAEs) in farmland. The detection frequencies of PAEs and mPAEs in the investigated soil-plant systems were 100 %. The total concentrations of PAEs in the collected soil and plant samples ranged from 0.07 to 1.83 mg/kg (dw) and from 3.9 to 24 mg/kg (dw), respectively. Moreover, di-(2-ethylhexyl) phthalate, diisobutyl phthalate and di-n-butyl phthalate were the predominant PAE congeners in the farmlands of eastern China, collectively accounting for >90 % of the total concentration of PAEs. In addition, the total concentrations of the two mPAEs were markedly higher in plant samples (49 ng/g dw to 549 ng/g dw) than in soil samples (3 ng/g dw to 22 ng/g dw), indicating that PAEs are readily metabolized in plants. The hazard index (HI) values of all PAEs in all crops were <1, demonstrating that the risks of PAEs in the crops were acceptable. However, the daily intake of mPAEs from the consumption of cabbage was higher than or comparable to that of some PAEs (such as di-n-octyl phthalate). This highlights the importance of taking metabolites into consideration in further environmental investigations and risk assessments of PAEs.

Phthalate esters and their metabolites in paired soil-crop systems from farmland in major provinces of eastern China: Pollution characteristics and implications for human exposure.

A precise analytical method based on QuEChERS has been proposed for the concurrent determination of 11 polyhalogenated carbazoles (PHCZs), benzocarbazole (BZCZ), and 9H-carbazoles (CZ). The quantification was confirmed by gas chromatography using triple quadrupole tandem mass spectrometry (Shimadzu GC-MS/MS-TQ8040) and gas chromatography coupled mass spectrometry (Agilent 7890A-5973 GC-MS). The developed method was validated by testing the following parameters: linearity, instrument limit of detection (LOD), instrument limit of quantification (LOQ), method limit of detection (MLD), method limit of quantification (MLQ), matrix effect (ME), accuracy, and precision. All compounds showed good linearity in the range of 0.005-0.2 μg/mL with correlation coefficients higher than 0.992. The method demonstrated satisfactory recoveries (ranging from 71.21 to 105.04%) for most of the compounds with relative standard deviation precision (RSD) < 10.46%, except 3-BCZ (Recovery = 67.53%, RSD = 2.83%). The values of LOD and LOQ varied from 0.05 to 0.24 ng and 0.14 to 0.92 ng, respectively, while those of MLD and MLQ ranged from 0.02 to 0.12 ng/g wet weight (ww) and 0.07 to 0.45 ng/g ww, respectively. The developed method represents a reliable tool for the routine analysis of PHCZ congeners in invertebrate animals.

Analysis of polyhalogenated carbazoles and two related compounds in earthworms using a modified QuEChERS method with GC/MS and GC/MS/MS.

Plant accumulation of phenolic contaminants from agricultural soils can cause human health risks via the food chain. However, experimental and predictive information for plant uptake and accumulation of bisphenol congeners is lacking. In this study, the uptake, translocation, and accumulation of five bisphenols (BPs) in carrot and lettuce plants were investigated through hydroponic culture (duration of 168 h) and soil culture (duration of 42 days) systems. The results suggested a higher bioconcentration factor (BCF) of bisphenol AF (BPAF) in plants than that of the other four BPs. A positive correlation was found between the log BCF and the log K of BPs (R = 0.987, R = 0.801, P < 0.05), while the log (translocation factor) exhibited a negative correlation with the log K (R = 0.957, R = 0.960, P < 0.05). The results of molecular docking revealed that the lower binding energy of BPAF with glycosyltransferase, glutathione S-transferase, and cytochrome P450 (-4.34, -4.05, and -3.52 kcal/mol) would be responsible for its higher accumulation in plants. Based on the experimental data, an attention mechanism multi-layer perceptron (AM-MLP) model was developed to predict the BCF of eight untested BPs by machine learning, suggesting the relatively high BCF of bisphenol BP, bisphenol PH, and bisphenol TMC (BCF = 1.37, 1.50, 1.03; BCF = 1.02, 0.98, 0.67). The prediction of BCF for ever-increasing varieties of BPs by machine learning would reduce repetitive experimental tests and save resources, providing scientific guidance for the production and application of BPs from the perspective of priority pollutants.

Congener-specific uptake and accumulation of bisphenols in edible plants: Binding to prediction of bioaccumulation by attention mechanism multi-layer perceptron machine learning model.

Article Total : 2	Year
Publication title	2023
Publication title	2023

Article	Year
Alteration of dominant cyanobacteria in different bloom periods caused by abiotic factors and species interactions. Journal of environmental sciences (China)\| PubMed ID: 33183685	2021
Trophic transfer of Cu nanoparticles in a simulated aquatic food chain. Ecotoxicology and environmental safety\| PubMed ID: 35905628	2022
Human exposure to phthalate esters in soils embodied in interregional food trade in China. Environmental pollution (Barking, Essex : 1987)\| PubMed ID: 36220577	2022
Congener-Specific Uptake and Metabolism of Bisphenols in Carrot Cells: Dissipation Kinetics, Biotransformation, and Enzyme Responses. Journal of agricultural and food chemistry\| PubMed ID: 36649116	2023
Toxicokinetics and Particle Number-Based Trophic Transfer of a Metallic Nanoparticle Mixture in a Terrestrial Food Chain. Environmental science & technology\| PubMed ID: 36747472	2023
Phthalate esters and their metabolites in paired soil-crop systems from farmland in major provinces of eastern China: Pollution characteristics and implications for human exposure. The Science of the total environment\| PubMed ID: 37088394	2023
Analysis of polyhalogenated carbazoles and two related compounds in earthworms using a modified QuEChERS method with GC/MS and GC/MS/MS. Environmental science and pollution research international\| PubMed ID: 37405602	2023
Congener-specific uptake and accumulation of bisphenols in edible plants: Binding to prediction of bioaccumulation by attention mechanism multi-layer perceptron machine learning model. Environmental pollution (Barking, Essex : 1987)\| PubMed ID: 37714399	2023

Juan Wu

Biography

JoVE Journal Publications

Other Publications