Antibiotics enrich antibiotic resistance genes (ARGs) and virulence factor genes (VFGs) in farmland, but the contribution of microplastics (MPs) to this process remains unclear. Here, through metagenome analysis, we revealed the add-on effects of PE and PLA on ARGs and VFGs enrichment in rice seedling rhizosphere soil under florfenicol (FF) stress. Compared with controls, root iron plaque content decreased by 35%, 66% and 69% under FF, FF + PE and FF + PLA treatments, disrupting microbial iron balance and activating ABC transporter pathways. Loss of beneficial/core microbes weakened community resistance; bacteria were more sensitive to stress than fungi. Among 945 ARGs and 391 VFs detected, antibiotic efflux abundance rose by 184% under FF, while mobile genetic elements (MGEs) increased from 0.5% to 38.1%, facilitating horizontal ARG transfer. In addition to horizontal gene transfer (HGT) mediated by mobile genetic elements (MGEs), our finding suggests a potential mechanism by which virulence factors (VFs) may promote ARG enrichment through the accumulation of tissue-damaging free radicals. Only one ARG-carrying human pathogen existed in controls, whereas six multi-drug-resistant pathogens emerged under combined pollution. This study provides new insights into the environmental risks of the add-on effects of MPs under antibiotics stress and contributing to the "One Health" goal.

Estuarine systems, where intensified biogeochemical processes enhance polycyclic aromatic hydrocarbons (PAHs) accumulation and water-air exchange critically governs contaminant transport, require deeper understanding of land-use and anthropogenic drivers. This study quantifies PAH dynamics in a representative semi-enclosed watershed-estuary system, revealing dissolved concentrations from 2.0 to 49.2 ng/L (normal season), 2.3-37.4 ng/L (flood season), and 2.7-34.8 ng/L (dry season), while atmospheric levels peaking in winter (8.9-250.4 ng/m3). Dissolved PAHs exhibited about 1.5- to 1.9-fold estuarine enrichment during normal/flood seasons but reversed to inland dominance in dry periods, while gaseous PAHs showed consistent estuarine enrichment. Net deposition fluxes (-0.02 to -0.64 ng/m2/day) peaked in winter due to elevated gaseous concentrations and lower temperatures. Land-use conflicts dictated source-sink balances, with construction zones (0.5 km radius) as emission hotspots and waters/wetlands (2 km radius) as primary sinks. Positive Matrix Factorization identified traffic emissions, petrogenic, and coal/biomass combustion sources. PCA-K-means clustering resolved distinct spatiotemporal patterns, including dry-season biomass clusters (48.2%) near construction areas, petrogenic-dominated areas (56.9%) mobilizing during floods, and traffic-intensive residential zones requiring emission controls. Spearman correlation analysis and redundancy analysis (RDA) demonstrated a notable decoupling trend: improved energy structures were significantly associated with decreased high-molecular-weight PAH emissions, whereas the increase in vehicle numbers presented a dual challenge, mitigating gaseous low-molecular-weight PAHs but aggravating aquatic middle-molecular-weight PAHs via road runoff. These findings establish a regional conceptual model illustrating how hydrological forcing, energy structure transitions, and transportation dynamics collectively modulate coastal PAH transport, offering mechanistic insights for pollution mitigation in similar urbanized estuaries.

Antibiotics, as emerging environmental contaminants, pose potential risks to crop photosynthesis and productivity. This study systematically investigated the phytotoxic effects of enrofloxacin (ENR), levofloxacin (LVX), and roxithromycin (ROX) on wheat (Triticum aestivum L.) seedlings. Exposure to ENR and LVX led to significant reductions in photosynthetic pigment content, chlorophyll synthesis precursors, and net photosynthetic rate, accompanied by severe chloroplast ultrastructural damage, thylakoid disintegration, and mitochondrial cristae impairment. Chlorophyll fluorescence parameters indicated PSII dysfunction and impaired electron transport under ENR and LVX stress. In contrast, ROX treatment increased pigment content, maintained chloroplast integrity, and increased chloroplast numbers. All three antibiotics stimulated key carbon assimilation enzymes including Rubisco, PEPC, NADP-ME, and PPDK. Transcriptomic analysis revealed downregulation of photosynthesis-related genes (e.g., PsbA, PsaA, PetA, PetD) and F-type ATPase subunits under ENR and LVX, whereas genes involved in redox maintenance (PetH) were upregulated. Metabolomic profiling showed accumulation of oxalic acid, methylamine, and palmitic acid under ENR and LVX, indicating membrane damage, protein degradation, and may disrupt energy metabolism. Significant alterations in fatty acid biosynthesis, pyrimidine metabolism, and GPI anchor biosynthesis pathways further confirmed antibiotic-induced metabolic reprogramming. This study provides new insights into the differential impacts of antibiotics on crop photosynthesis and cellular integrity, emphasizing the need for ecological risk assessment of antibiotic contamination in agricultural systems.

Sulfonamide antibiotics (SAs) are widely detected in agricultural environments due to their extensive use in livestock farming, yet their phytotoxic mechanisms remain poorly understood. Here, we investigated the toxicity mechanisms of three SAs-sulfamethoxazole (SMX), sulfadiazine (SD), and sulfamethazine (SM2)-on wheat seedlings using integrated physiological, biochemical, and metabolomic approaches. The three SAs exhibited phytotoxicity with growth inhibition following the order SMX > SD > SM2; root inhibition rates reached 70.83%, 65.97%, and 48.89%, respectively, under 10 mg & centerdot;L-1 treatment. SAs severely disrupted the photosynthetic system. Chlorophyll pigments and their biosynthetic precursors (Proto IX, Mg-Proto IX, and Pchlide) decreased to 0.56-0.94 times that of the control under 50 mg & centerdot;L-1 treatment. Chlorophyll fluorescence parameters were markedly impaired, indicating impaired photosystem II function. Concurrently, SAs induced severe oxidative stress, as evidenced by up to1.84-fold increase in cell membrane permeability, 4.05-fold and 1.57-fold elevations in malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels, respectively, and significant activation of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase). Laser confocal microscopy and flow cytometry confirmed substantial reactive oxygen species accumulation. Correlation analysis revealed a significant negative relationship between oxidative stress indicators and photosynthetic parameters. Metabolomics analysis revealed that SAs reprogrammed central metabolism, with significant upregulation of TCA cycle intermediates (e.g., succinate, fumarate) and key amino acids (L-alanine, glycine, l-serine, L-threonine), reflecting an active compensatory energy and antioxidant response. These findings provide a comprehensive mechanistic understanding of SAs phytotoxicity in crops and highlight the potential risks of antibiotic contamination to agricultural productivity. Our results underscore the need for optimized wastewater treatment and the establishment of irrigation water quality standards to mitigate antibiotic risks to food safety and crop yield. Environmental implication The worldwide use of antibiotics has led to multiple phytotoxicity and high risk to humans. The manuscript attempts to reveal the effects of sulfonamide antibiotics on wheat seedlings, including growth inhibition, oxidative stress, and photosynthetic damage. Laser confocal scanning and flow cytometry were used to evaluate the ROS accumulation and cytoplasmic ROS levels. Integration of biomarker responses, principal component analysis, and Pearson's correlation coefficient are used to reveal relationship among the parameters. Metabolomics is used to analyze metabolic pathways and metabolites. The results will provide theoretical basis for crop safety production and a new perspective for ecological risk assessment.

The effects of foliar spraying different concentrations of glutathione （GSH）， cysteine （Cys）， and glutamic acid （Glu） on the phytoremediation by Solanum nigrum L. in heavy metal-contaminated soil were systematically investigated under the light conditions of 20% red light， 70% blue light， and 10% green light （R20B70G10）. The application of GSH， Cys， and Glu at various levels through foliar spraying yielded the following results： ① It promoted the growth of S. nigrum L. by increasing the dry weight of the plants by 15.0%-89.4%. Among them， the application of 2 mmol·L-1 GSH increased the dry weight of the plants by 82.0%. Furthermore， it enhanced the growth and elongation of the aboveground and underground parts of the plants， with plant height and root length exhibiting increases of 48.1% and 36.8%， respectively. ② It enhanced the photosynthetic efficiency of plants. The application of 2 mmol·L-1 GSH was shown to significantly enhance the actual photosynthetic efficiency [Y（Ⅱ）] and the photosynthetic electron transport rate （ETR） of photosystem Ⅱ in plants， with respective increases of 76.8% and 78.3% compared to those in the control group. ③ It enhanced the antioxidant capacity of S. nigrum L. The content of ascorbic acid （AsA） and GSH in the plant leaves increased by 22.7%-140.2% and 21.1%-80.6%， respectively. Among them， foliar spraying 2 mmol·L-1 GSH increased the AsA and GSH contents in the leaves by 126.4% and 57.1%， respectively. The activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） in the plants increased by 137.5%， 312.3%， and 33.2%， respectively， and the activities of dehydroascorbate reductase （DHAR） and ascorbate peroxidase （APX） in the plants increased by 34.8% and 81.9%， respectively. The contents of malondialdehyde （MDA） and hydrogen peroxide （H2O2） in the plants decreased by 39.0% and 32.3%， respectively. ④ It also enhanced the activities of neutral phosphatase （NPH） and urease （URE） in the rhizosphere soil of S. nigrum L. The activities of NPH and URE in the soil increased by 11.4%-91.6% and 25.6%-111.4%， respectively. Among them， the activities of NPH and URE increased by 81.1% and 67.6%， respectively， when 2 mmol·L-1 GSH was applied through foliar spraying. ⑤ The effectiveness of S. nigrum L. in remediating heavy metal-contaminated soil was strengthened. Foliar spraying of GSH and Cys could significantly increase the accumulation of cadmium （Cd） in S. nigrum L. Among them， the application of 2 mmol·L-1 GSH significantly improved the accumulation and translocation capacity of S. nigrum L. for Cd. Specifically， its translocation factor （TF）， bioconcentration factor （BCF）， and total extraction （TE） increased by 97.2%， 148.7%， and 209.4%， respectively， and the maximum value of TE could reach 0.132 mg·plant-1. Thus， foliar spraying of 2 mmol·L-1 GSH， Cys， and Glu can significantly increase the biomass of S. nigrum L. under heavy metal stress. It enhances the antioxidant capacity and reduces oxidative damage， promotes the plant to absorb and accumulates heavy metals， and strengthens the phytoremediation effect. Overall， the treatment of foliar spraying 2 mmol·L-1 GSH had the best effect.

The soil pollution of heavy metals (HMs) is becoming a critical global environmental issue that could pose risk to the human health, especially for the regions with the rapid economic development. In this study, an integrated assessment framework combining multi-source environmental data and machine learning (ML) approaches was developed to evaluate the spatiotemporal evolution and health risks of 8 HMs over a 20-year period (2001-2020) in the Yangtze River Delta. Among the HMs, the concentration of copper, chromium, nickel and zinc generally showed a downward trend, while the lead, arsenic, and mercury showed a fluctuating trend. The cadmium (Cd) emerged as a primary pollutant, with soil concentrations showing a marked increase from 2001 to 2020. Feature importance analysis identified industrial (23.39 %), transportation (21.08 %), and agricultural activities (19.79 %) as main contributors to soil Cd accumulation. By constructing and comparing nine ML models, we determined that an optimized extreme gradient boosting (XGB) model provided the best predictive performance of Cd concentration. It successfully predicted the soil Cd concentrations in 2024, which aligned well with subsequent field measurements. A health risk assessment integrating the XGB model with Monte Carlo simulation showed the increasing carcinogenic risk of Cd for children over the next five years, with the dominant risk source shifting from transportation (51.3 %) to agricultural activities (38.5 %). Path analysis confirmed the significant and direct effects of transportation (path coefficient = 0.55) and agricultural sources (path coefficient = 0.26) on Cd contamination. The established framework provides an effective methodology for the dynamic assessment and proactive management of soil HM pollution in rapidly developing regions.

The presence of sedimentary microplastics (MPs) remains a significant concern due to their substantial contribution to the "missing" MPs in marine environments and their crucial role in the global MP cycle. In this study, we investigated MPs in sediments from three representative bays in the Zhejiang Great Bay Area, China, and examined their sources and mass budgets within these bay systems. High spatial similarities were observed among these regions. In Hangzhou Bay, sedimentary MPs primarily originated from textile and fishing activities, while local mariculture and coastal tourism significantly influenced MP levels in Sanmen Bay. In Wenzhou Bay, packaging and agricultural sources contributed to the presence of MPs. Riverine discharges are crucial for MP mass budget in the three bays, accounting for 41.5 %-96.7 % of the total. Hydrodynamic conditions and topographic features significantly influence oceanic inflow/outflow patterns that affect both water column and sediment MPs. The estimated retention time suggests that these bay systems serve as temporary reservoirs, facilitating the migration of part of MPs from land to open sea. Importantly, the continuous transport pathways, whether through offshore-bound MPs in the water or sediment-resuspended particles, create persistent mobilization mechanisms that may enhance ecological risks in marine ecosystems. These findings emphasize the need for timely action to reduce MP pollution in bay environments and provide valuable information for future policy development regarding MPs.

Identifying key genes that regulate plant responses to heavy metals (HMs) is crucial for developing effective strategies to limit HM accumulation. While abscisic acid (ABA) is known to mediate stress responses, the molecular mechanisms linking ABA signaling to HM tolerance are poorly understood. This study revealed CEPR2 as the critical receptor-like kinase that integrates ABA-mediated signaling with HM uptake regulation, a novel role not previously reported. Loss-of-function cepr2 mutants exhibited significantly enhanced biomass (30.3% and 32.2% in shoots, 84.1% and 89.7% in roots) under HM/ABA stress compared to WT and CEPR2 overexpressing lines, alongside higher chlorophyll content and photosynthetic activity. Crucially, ABA-induced suppression of HM accumulation in cepr2 was displayed through downregulation of HM absorption-related genes─FIT, IRT1, FRO2, HMA4, NRAMP6, and BTS genes. Structural equation modeling further established CEPR2 as a central node negatively correlating with ABA content but positively with the HM transporter expression that regulates HM accumulation. The present study provides insights into the molecular mechanism mediated by LRR-RLK in response to HM stress and theoretical support for developing strategies to limit HMs in plants.

The horizontal transfer of antibiotic resistance genes (ARGs) has become a major threat to global public health. Recent studies have found that ferroptosis, an iron-dependent form of regulated cell death characterized by lipid peroxidation and glutathione depletion, may play a critical role in the dissemination of ARGs among environmental microbes. Here, we demonstrated for the first time that phthalate esters (PAEs) and their substitutes significantly enhanced plasmid conjugation by triggering ferroptosis-related pathways. Classical ferroptosis-associated responses, including the hyperpolarization of the cell membrane potential, elevated production of reactive oxygen species, and heightened membrane permeability, were observed under the stress of PAEs or their substitutes. Through integrated transcriptomic and metabolomic analyses, we revealed that these compounds triggered iron dysregulation via the upregulation of iron acquisition and storage pathways while suppressing DNA replication, concurrently causing oxidative damage that stimulated the plasmid conjugation. Molecular docking simulations revealed that PAEs and their substitutes competitively disrupted the functionality of ferric uptake regulator (Fur) protein, a master controller of intracellular iron homeostasis, with superior binding affinity than its natural ligand Fe2+. Integrated metagenomic sequencing and homology analyses demonstrated the conservation of Fur protein across biofilm microbiota and functional implications in iron homeostasis. Structural analysis based on the characteristic molecular fingerprints of chemicals pinpointed aliphatic chains as the crucial structure responsible for enhancing ARG propagation between bacteria. Our findings uncovered a mechanism by which PAEs and their substitutes exacerbated ARG dissemination through ferroptosis-mediated conjugation, providing crucial insights for environmental risk assessment and resistance mitigation strategies.

Due to its similarity in hydrophobic properties to perfluorooctanesulfonic acid (PFOS), 6:2 fluorotelomer sulfonic acid (6:2 FTSA) has emerged as a key substitute for PFOS. Its presence in aquatic environments, along with the coexistence of polyethylene terephthalate (PET), may impact the growth of aquatic plants and ecosystem stability. This study explored the changes in antioxidant defense, photosynthetic system, and metabolic responses of water hyacinths (Eichhornia crassipes) under individual and combined exposure conditions. The results indicated that water hyacinth efficiently accumulated 6:2 FTSA, with notably higher accumulation levels in leaves compared to roots, leading to a more pronounced stress response in leaves. The contents of nitrate, nitrite, ammonium, and the activities of nitrogen assimilation enzymes in leaves increased significantly, which in turn boosted the levels of reactive oxygen species (ROS) scavengers such as glutamic acid and glutathione, as well as antioxidant defense enzymes. Meanwhile, leaf photosynthesis was significantly suppressed due to the resource reallocation. This was corroborated by disruptions in the chloroplast thylakoid structure and alterations in chlorophyll fluorescence parameters. Metabolomics analysis further revealed that the contents of monosaccharides and organic acids decreased markedly, whereas amino acid levels increased significantly, suggesting that water hyacinths prioritized antioxidant defense mechanisms at the expense of growth. Additionally, we observed that the phytotoxic effects of 6:2 FTSA were exacerbated in the presence of PET nanoplastics, with the aforementioned indicators exhibiting synergistic effects. This study provides phenotypic, physiological, metabolic, and transcriptional insights into the toxic effects of the coexistence of PET nanoplastics and 6:2 FTSA on water hyacinths, offering toxicological data (e.g., oxidative stress markers and gene expression profiles) for assessing the environmental risks associated with emerging contaminants and proposing management strategies.

Understanding the combined toxicity mechanisms of polybrominated diphenyl ethers (PBDEs) and nanoplastics is essential for ecological risk management. This study integrated physiological, transcriptomic, metabolomic, and computational analyses to investigate the synergistic phytotoxicity of polyethylene (PE) nanoplastics and 2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) in rice (Oryza sativa L.). Co-exposure synergistically intensified toxicity compared to isolated treatments, causing 14.8 %-42.8 % reductions (P < 0.001) in enzymatic antioxidants such as peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX) activities and non-enzymatic antioxidants oxidized glutathione (GSSG) and ascorbate (AsA) levels, alongside inhibited root and shoot growth. Transcriptomic data revealed suppressed expression of photosystem II genes (psbO, psbW), correlating with impaired photosynthesis, energy deficits, and growth restriction. Concurrently, glutathione biosynthesis genes (OsGLN2, OsGS1, OsGPX1/4) were downregulated, disrupting glutamine-to-glutathione (GSH) conversion. Metabolomic analysis confirmed 3.5-fold glutamate depletion and inhibited carbohydrate metabolism, indicating pollutant-induced oxidative stress. Molecular docking simulations identified OsGPX1 as BDE-47 ' s binding target through hydrogen-bond interactions, which competitively blocked GSH binding to glutathione peroxidase (GPX). This demonstrated that nanoplastics act as chemical potentiators, amplifying PBDEs toxicity via enzyme inhibition and metabolic interference. Specifically, PE enhanced BDE-47 ' s capacity to disrupt redox homeostasis and energy metabolism through direct protein interactions and pathway dysregulation. These findings would provide mechanistic insights into pollutant synergism, emphasizing the need to evaluate nanoplastic co-contaminants in environmental risk frameworks.

In this study, a pyrolysis-gas chromatography/mass spectrometry method was established to quantify microplastics (MPs) released from plastic food containers during rinsing and migration. The inner surface of actual samples was rinsed with deionized water, and the MPs in rinse water were collected through a glass fiber membrane with pore size of 1 μm. Subsequently, thoroughly cleaned polypropylene (PP) food packaging containers were selected for migration tests under different simulants, migration temperatures, and migration times. It was found that MPs corresponding to the materials of product manufacture were detected in all collected containers during rinsing. By migration tests, the results showed that high-fat foods, high/low temperature (5 °C), and long exposure periods can promote the release of MPs. It was also proved that the migration of MPs from plastic food containers was one of the important sources for human exposure to MPs. The obtained results can provide evidence for the safety risk assessment of plastic food containers.

The potential of silicon nanoparticles (SiNP) to alleviate abiotic stress is recognized, but their effect on antibiotic stress remains unexplored. Sulfamethoxazole (SMX), a typical sulfonamide antibiotic, has attracted much attention due to its ecological risks. This study investigates the mechanisms by which SiNP mitigates sulfamethoxazole (SMX) toxicity in wheat seedlings. SiNP application (400 mg center dot L-1) significantly reversed SMXinduced growth inhibition, restoring shoot and root length by 28 % and 57 %, respectively. It alleviated phototoxicity by restoring chlorophyll content and photosystem II efficiency, reduced oxidative damage by decreasing H2O2and malondialdehyde (MDA) levels while enhancing the antioxidant enzyme system and ascorbic acid-glutathione (AsA-GSH) cycle. Multivariate analysis confirmed that SiNP protection primarily involved regulating antioxidant and photosynthetic pathways. Crucially, transcriptomic and metabolomic analyses revealed a novel mechanism: SiNP reprogrammed carbon and nitrogen metabolism by specifically enhancing Calvin cycle intermediates and rebalancing alanine, aspartate, and glutamate metabolism, thereby restoring energy and metabolic homeostasis. This study provides the first evidence of SiNP's efficacy and unique regulatory mechanism against antibiotic stress, offering a theoretical basis for its application in mitigating organic pollutant contamination in agriculture.

Heavy metal contamination of soil is a serious environmental issue that threatens agricultural products and human health. Previous studies have shown that abscisic acid (ABA)-producing bacteria can effectively decrease heavy metal accumulation in plants. However, the broader applicability of this approach across varying soil types remains undetermined, revealing significant gaps in understanding its real-world implementation under distinct edaphic conditions. Garden soils were collected from Zhejiang, Sichuan, and Heilongjiang Provinces to investigate the effects of ABA-producing bacteria in reducing heavy metal accumulation in vegetable crops grown in moderately contaminated soils in this study. Inoculating the ABA-producing bacterium Azospirillum brasilense decreased heavy metals contents, including cadmium (Cd), nickel (Ni), lead (Pb), and zinc (Zn) in pak choi grown in the soil from Zhejiang, Heilongjiang, and Sichuan Provinces by 30.2-52.4 %, 24.1-30.1 %, and 22.0-49.2 %, respectively. Additionally, pak choi biomass increased significantly by 134.3 %, 87.9 %, and 126.3 % in these soils, respectively. These results indicated that ABA-producing bacteria universally benefited from heavy metal reduction and yield improvement. Further analysis revealed that the ABA levels in plants increased by 24.7 %, 27.7 %, and 11.9 %, IRT1 expression decreased by 34.9 %, 8.6 %, and 30.8 %, and IRT2 expression decreased by 34.2 %, 20.1 %, and 9.2 % in those soils, respectively. Structural equation modeling analysis confirmed that increased soil pH and decreased available heavy metals contributed to the reduced heavy metal accumulation in pak choi. Overall, the ABA-producing bacteria effectively reduced heavy metal accumulation and enhanced biomass across different soil types, with the most pronounced effect observed in the soil of Zhejiang. Consequently, the application of ABA-generating bacteria may be an alternative strategy for improving the biomass production and quality of vegetable plants grown in heavy metal-contaminated soils.

Antibiotic contamination in agricultural systems via organic fertilizer application and livestock wastewater irrigation are threats to crop physiology. However, the phytotoxic mechanisms affecting the pivotal carbon-nitrogen (C-N) metabolic nexus remain unclear. In this study, we investigated florfenicol-induced perturbations in C-N metabolic networks and associated gene regulatory pathways in soybean (Glycine max) seedlings. Florfenicol exposure significantly inhibited growth, impaired cellular ultrastructure, reduced chlorophyll content, which decreased by 60.24 % in the 2 mg/kg treatment, and reduced RuBisCO content, which decreased by 34.15 % in the 2 mg/kg treatment. Chlorophyll fluorescence parameters were also affected. Photosystem damage inhibited carbon metabolism, including reduced photosynthates and decreased key carbon metabolism enzymes. Sucrose synthase decreased by 29.90 % in the leaves and 22.56 % in the roots in the 2 mg/kg treatment. The interruption of nitrogen assimilation was evidenced by the change in the content of nitrogen assimilation products and the activity of key nitrogen metabolism enzymes. Nitrate reductase significantly decreased by 63.06 % in the leaves and 69.23 % in the roots in the 2 mg/kg treatment. Transcription analysis showed that carbohydrate biosynthesis and nitrogen metabolism were downregulated. Differentially expressed genes (DEGs) associated with photosynthesis, C-N metabolism, and C-N-linked metabolic networks were significantly downregulated. I1LJG4 and HemG were the bottleneck genes of DEGs in nitrogen metabolism, and PURD was the bottleneck gene in carbon metabolism. Glycolysis blockade leads to a reduction in the carbon skeleton required for nitrogen metabolism, significantly downregulating nitrogen assimilation and transport. These findings indicate a mechanism by which veterinary antibiotics disrupt the primary metabolism in plants.

A method for the determination of brominated flame retardants was established by micro sample pretreatment technology combined with ion chromatography. Using a sealed glass capillary as a micro reactor, the brominated flame retardants were debrominated by pyrolysis at 300 degrees C and absorbed by absorbing liquid, followed by ion chromatography determination. To improve the debromination efficiency, important factors including pyrolysis time and absorbing liquid were investigated. The linearity of the method was satisfactory over a Br- concentration of 0.05-100 mg/L and the determination coefficient was greater than 0.999. The limit of detection and limit of quantitation of bromide ion were 1.50 mu g/L and 5.00 mu g/L, respectively. The potential of the established method was assessed by applying it to the determination of total bromine in actual electrical and electronic equipment. The average recoveries (97.1-104.2 %) and the precision (3.1-7.5 %) were achieved by real samples spiked with three levels. This proposed method, with simple operation and low cost, could be a good supplementary for the oxygen bomb combustion-ion chromatography method for the determination of brominated flame retardants in electrical and electronic products.

Using poly(styrene-divinylbenzene) microspheres as stationary phase matrix and mercaptosuccinic acid as a modifier, a new weak cation exchange resin was synthesized by thiol click reaction. The conditions for thiol-chlorine click reaction and thiol-alkene click reaction were optimized. The surface morphology and chemical composition of the modified microspheres were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and an elemental analyzer. The stationary phase can achieve the separation of six common cations within 25 min. A homemade weak cation chromatographic column was used to determine the impurities of Na+ and K+ and the content of tetramethylammonium ions in tetramethylammonium hydroxide samples. The method showed a good linear correlation in the range of 0.1-500.0 mg/L with correlation coefficients of 0.9998-0.9999, and the limits of detection (signal-to-noise ratio ≥ 3) were 0.01-0.20 mg/L. The intra-day relative standard deviations (RSDs) were in the range of 1.1%-4.4%, and the inter-day RSDs were in the range of 0.8%-14.8%. The spiked recoveries were in the range of 91.92%-119.86%. The results showed that the prepared stationary phase exhibited effective separation ability and good reproducibility, which was suitable for the analysis of the impurities of Na+, K+, and the content of tetramethylammonium in the tetramethylammonium reagents.

Growing concerns have raised about the microplastic eco-coronas in the ultraviolet (UV) disinfection wastewater, which accelerated the pollution of antibiotic resistance genes (ARGs) in the aquatic environment. As the hotspot of gene exchange, microplastics (MPs), especially for the UV-aged MPs, could alter the spread of ARGs in the eco-coronas and affect the resistance of the environment through adsorbing antibiotic resistant plasmids (ARPs). However, the relationship between the MP adsorption for ARPs and ARG spreading characteristics in MP eco-corona remain unclear. Herein, this study explored the distribution of ARGs in the MP eco-corona through in situ investigations of the discharged wastewater, and the adsorption behaviors of MPs for ARPs by in vitro adsorption experiments and in silico calculations. Results showed that the adsorption capacity of MPs for ARPs was enhanced by 42.7-48.0 % and the adsorption behavior changed from monolayer to multilayer adsorption after UV-aging. It was related to the increased surface roughness and oxygen-containing functional groups of MPs under UV treatment. Moreover, the abundance of ARGs in MP eco-corona of UV-treated wastewater was 1.33-1.55 folds higher than that without UV treatment, promoting the proliferation of drug resistance. DFT and DLVO theoretical calculations indicated that the MP-ARP interactions were dominated by electrostatic physical adsorption, endowing the aged MPs with low potential oxygen-containing groups to increase the electrostatic interaction with ARPs. Besides, due to the desorption of ARPs on MPs driven by the electrostatic repulsion, the bioavailability of ARGs in the MP eco-coronas was increased with pH and decreased with salinity after the wastewater discharge. Overall, this study advanced the understanding of the adsorption behavior of MPs for ARPs and provided inspirations for the evaluation of the resistance spread in the aquatic environment mediated by MP eco-coronas.

Massive use of plastic products has caused their accumulation in soils, releasing large amounts of endogenous plastic additives (e.g., benzotriazole ultraviolet stabilizers, in short BZT-UVs) into terrestrial ecosystems. However, their plant toxicity is little known. Herein, we investigated the occurrence of BZT-UVs in contaminated farmland and selected three BZT-UV congeners to explore their toxic effects on the antioxidant, photosynthetic, and metabolic perturbation on rice (Oryza sativa). Results showed that the mean concentrations of ∑BZT-UVs in soil and plant samples were 180.7 ng/g dw and 156.4 ng/g dw, respectively. UV-P, UV-327 and UV-328 were the dominant BZT-UV congeners in both of soils and plants. Three BZT-UV congeners caused oxidative damages to rice in a dose-dependent manner, especially for UV-328. Functional genes involved in chlorophyll synthetases was inhibited by over 50 % under the stress of BZT-UVs, whereas those responsible for chlorophyll degradation were obviously promoted. The chlorophyll content was thus decreased, leading to a weakened photosynthesis system and an unbalanced carbon metabolism. The transcriptome and metabolome proved that the flux of carbohydrate metabolism and amino acid metabolism were obviously promoted in plants induced by BZT-UVs, which could inhibit the growth of rice. These findings offered insights into the coordinated responses of plants and advanced our understanding of potential ecological risks of BZT-UVs to terrestrial ecosystems.

This study investigated dissolved PAHs and OCPs in Quanzhou Bay estuaries, assessed their ecological risk, and examined anthropogenic impacts on contaminant distribution. Results showed that dissolved ∑24PAH concentrations ranged from 117 to 709 ng/L (mean: 358 ng/L), with dominance of 2-ring PAHs (Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene). Dissolved DDT levels ranged from 0.06 to 0.49 ng/L (mean: 0.28 ng/L), while HCBz concentrations varied from 0.02 to 0.44 ng/L (mean: 0.20 ng/L). PAHs were higher in the north due to urbanization and transport, while OCPs showed higher levels in the south due to historical agricultural use. Rural areas, water bodies, and wetlands significantly influenced the behavior of PAHs according to Spearman correlation and lasso regression analyses. Quanzhou Bay was categorized as a low to medium risk area based on dispersion simulation and ecological risk assessment, highlighting implications for future sustainable development and policy planning. Capsule The coupled relationship between human activities and the distribution of dissolved PAHs and OCPs in urbanized estuaries was explored using statistical methods and GIS technology, providing valuable insights into environmental processes and pollutant control policies.