Perfluorooctanesulfonic acid (PFOS) is a persistent environmental contaminant previously found in consumer surfactants and industrial fire-fighting foams. PFOS has been widely implicated in metabolic dysfunction across the lifespan, including diabetes and obesity. However, the contributions of the embryonic environment to metabolic disease remain uncharacterized. This study seeks to identify perturbations in embryonic metabolism, pancreas development, and adiposity due to developmental and subchronic PFOS exposures and their persistence into later larval and juvenile periods. Zebrafish embryos were exposed to 16 or 32 μM PFOS developmentally (1–5 days post fertilization; dpf) or subchronically (1–15 dpf). Embryonic fatty acid and macronutrient concentrations and expression of peroxisome proliferator-activated receptor (PPAR) isoforms were quantified in embryos. Pancreatic islet morphometry was assessed at 15 and 30 dpf, and adiposity and fish behavior were assessed at 15 dpf. Concentrations of lauric (C12:0) and myristic (C14:0) saturated fatty acids were increased by PFOS at 4 dpf, and PPAR gene expression was reduced. Incidence of aberrant islet morphologies, principal islet areas, and adiposity were increased in 15 dpf larvae and 30 dpf juvenile fish. Together, these data suggest that the embryonic period is a susceptible window of metabolic programming in response to PFOS exposures, and that these early exposures alone can have persisting effects later in the lifecourse.

Sulfur, an essential macronutrient, plays important roles in plant development and stress mitigation. Sulfur deficiency, a common problem in agricultural soils, may disturb plant stress resistance and xenobiotic detoxification. In the present study, the function and mechanism of limited sulfur nutrition on the residues and phtotoxicity of imidacloprid were investigated in lettuce plants. Sulfur deficiency significantly increased imidacloprid accumulation in lettuce tissues, exacerbated imidacloprid biological toxicity by enhancing the accumulation of toxic metabolites, like imidacloprid-olefin. Simultaneously, imidacloprid-induced detoxification enzymes including cytochromes P450, glutathione S-transferases (GSTs) and glycosyltransferases were inhibited under limited sulfur supply. On the other hand, sulfur deficiency further enhanced the generation of reactive oxygen species and exacerbated lipid peroxidation in lettuce tissues. Sulfur deficiency mainly reduced the abundance of thiol groups, which are essential redox modulators as well as xenobiotic conjugators, and significantly inhibited GSTs expression. These results clearly suggested that sulfur deficiency inhibited the synthesis of sulfur-containing compounds, leading to increased accumulation of pesticide residues and toxic metabolites as well as reduced detoxification capacity, consequently leading to oxidative damage to plants. Therefore, moderate sulfur supply in regions where neonicotinoid insecticides are intensively and indiscriminately used may be an efficient strategy to reduce pesticide residues and the potential risk to ecosystem.

Heavy metal pollution is widespread, and has an increasing trend in some countries and regions. It can be easily accumulated in plants, leading to plant species loss and affecting plant community composition. Artificial restoration can conserve plant diversity in contaminated soils and accelerate the recovery of polluted ecosystems. The application of nitrogen (N) and phosphorus (P) is inexpensive and convenient, which can increase the resistance of plants to adversity and promote the growth of plants in heavy metal polluted soils. In order to examine the effect of N and P nutrition on the conservation of plant community, we conducted a comparison experiment in greenhouse using soil with low N and P concentration, and set five treatments: C (soil with no heavy metals and fertilizer addition), H (soil with heavy metals addition but with no fertilizer), HN (soil with heavy metals and N addition), HP treatment(soil with heavy metals and P addition), HNP treatment (soil with heavy metals, N and P addition). Our results showed that heavy metal pollution reduced plant species by 300%, and significantly decreased plant diversity (P < 0.05). N addition increased the richness of plant species and increased the dominance of Euphorbia peplus, but had no significant effect on plant diversity and community structure, while reduced the evenness of plant species. P addition of HP and HNP treatments restored plant species richness and increased plant diversity under heavy metal pollution. The plant community structures of these two treatments were more similar to that of group C. Compared with N addition, P addition had a better performance to restoring the species composition and relative dominance of plant communities. Our results provided a guidance for the restoration of plant communities and the conservation of plant species in low N and P concentration soils with the context of heavy metal pollution.

Plants have the ability to adapt themselves under stressed conditions through reprogramming their growth and development. Understanding the mechanisms regulating overall growth of stressed plant is an important issue for plant and environmental biology research. Although the role of NO in modulating arsenic (As) toxicity is known, nitric oxide (NO) induced alteration in auxin and nutrient related transporters during As stress in rice is poorly understood. Experimental results showed that As exposure decreased gene expression level of polar auxin transporter (PIN proteins), and nutrient transporter related genes (AMT, NRT, NiR, PHT, KTP). The improved tolerance induced by As + NO combination is attributed to reduced As accumulation in rice seedlings, improved root architectural changes, overall growth of plant, chlorophyll, protein content, and accumulation of mineral nutrients by reducing the ROS generation. Further, enhanced transcript levels of PIN proteins and mineral nutrition related genes were also observed under As + NO treatment. Additional biochemical data revealed enhanced oxidative stress by increasing the level of antioxidant enzymes, and stress-related parameters. Overall, the study provides an integrated view of plant response during As + NO interaction to change the plant metabolism through different cellular processes.

Given that cadmium (Cd) uptake by plants is linked to transpiration rate and activity of antioxidant enzymes and further that silicon (Si) can regulate them, it was hypothesized that improved Si nutrition could reduce Cd concentration in plants. Thus, present study was carried out to elucidate the positive effect of Si nutrition on the growth, activities of antioxidant enzymes and tissue cadmium (Cd) concentration in Cd-tolerant (Iqbal-2000) and Cd-sensitive wheat (Triticum aestivum L.) cultivars. Fifteen days after seedling transplantation, 15 μM Cd stress alone and in combination with 0.6 mM Si was applied. Silicon application improved root and shoot dry matter of Cd-sensitive cultivar Sehar-2006 while the effect was non-significant in Cd-tolerant cultivar Iqbal-2000. Silicon-treated Cd-sensitive cultivar showed marked improvements in chlorophyll content and photosynthesis, while stomatal conductance and transpiration rate decreased by Si application. Silicon treatment enhanced the activities of enzymatic antioxidants including catalase, ascorbate peroxidase, guaiacol peroxidase and superoxide dismutase and the increase was higher for Cd-tolerant cultivar Iqbal-2000. Although Si nutrition depressed malondialdehyde (MDA) content in both Cd-stressed cultivars, the response was more evident in Cd-sensitive Sehar-2006. Lower lipid peroxidation was related to Si-induced increase in antioxidant activities only in Cd-sensitive cultivar. Silicon application decreased Cd accumulation in the roots and shoots of both the cultivars. The decrease in shoot Cd was associated with a decrease in Cd uptake by roots and Cd translocation from roots to shoots. Overall, it is concluded that Si suppressed Cd contents by decreasing transpiration rate in Cd-sensitive cultivar and by increasing antioxidant activity in Cd-tolerant cultivar.

Acetochlor is a widely used chloroacetanilide herbicide and has posed environmental risks in soil and water due to its toxicity and high leaching capacity. Earthworm represents the dominant invertebrate in soil and can promote the decomposition of organic pollutants. The effect of earthworm on acetochlor degradation in soil was studied by soil column experiment with or without acetochlor and earthworm in sterile and natural soils. The degradation capacities of drilosphere components to acetochlor were investigated by microcosm experiments. Bacterial and fungal acetochlor degraders stimulated by earthworm were identified by high-throughput sequencing. The degradation kinetics of acetochlor suggested that both indigenous microorganisms and earthworm played important roles in acetochlor degradation. Acetochlor degradation was quicker in soil with earthworms than without earthworms, with the degradation rates increased by 62.3 ± 15.2% and 9.7 ± 1.7% in sterile and natural treatments respectively. The result was related to the neutralized pH, higher enzyme activities and enhanced soil microbial community diversity and richness in the presence of earthworms. Earthworm cast was the degradation hotpot in drilosphere and exhibited better anaerobic degradation capacity in microcosm experiments. The acetochlor degradation rate of cast in anaerobic environment was 12.0 ± 0.1% quicker than that in aerobic environment. Residual acetochlor in soil conferred a long-term impairment on fungal community, and this inhibition could be repaired by earthworm. Earthworm stimulated indigenous degraders like Sphingomonas and Microascales and carried suspected intestinal degraders like Mortierella and Escherichia_coli to degradation process. Cometabolism between nutrition cycle species and degraders in casts also contributed to its faster degradation rates. The study also presented some possible anaerobic degradation species like Rhodococcus, Pseudomonas_fulva and Methylobacillus.

Primitive electronic waste (e-waste) recycling releases large amounts of organic pollutants and heavy metals into the environment. As crucial moderators of geochemical cycling processes and pollutant remediation, soil microbes may be affected by these contaminants. We collected soil samples heavily contaminated by e-waste recycling in China and Pakistan, and analyzed the indigenous microbial communities. The results of this work revealed that the microbial community composition and diversity, at both whole and core community levels, were affected significantly by polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and heavy metals (e.g., Cu, Zn, and Pb). The geographical distance showed limited impacts on microbial communities compared with geochemical factors. The constructed ecological network of soil microbial communities illustrated microbial co-occurrence, competition and antagonism across soils, revealing the response of microbes to soil properties and pollutants. Two of the three main modules constructed with core operational taxonomic units (OTUs) were sensitive to nutrition (total organic carbon and total nitrogen) and pollutants. Five key OTUs assigned to Acidobacteria, Proteobacteria, and Nitrospirae in ecological network were identified. This is the first study to report the effects of e-waste pollutants on soil microbial network, providing a deeper understanding of the ecological influence of crude e-waste recycling activities on soil ecological functions.

Soil receiving discharges from Pb-acid batteries dismantling and restoring units (PBS) can have a high concentration of phytoavailable Pb. Reducing Pb phytoavailability in PBS can decline Pb uptake in food crops and minimize the risks to humans and the environment. This pot study aimed to reduce the concentration of phytoavailable Pb in PBS through Aspergillus niger (A. niger)−mediated release of PO₄³⁻ from fish bone [Apatite II (APII)] products. The PBS (Pb = 639 mg kg⁻¹ soil) was amended with APII powder (APII−P), APII char (APII−C), and A. niger inoculum as separate doses, and combining A. niger with APII−P (APII−P + A. niger) and APII−C (APII−C + A. niger). The effects of these treatments on reducing the phytoavailability of Pb in PBS and its uptake in fenugreek were examined. Additionally, enzymatic activities and microbial biomass carbon (MBC) in the PBS and the indices of plant physiology, nutrition, and antioxidant defense machinery were scoped. Results revealed that the APII−C + A. niger treatment was the most efficient one. Compared to the control, it significantly reduced the Pb phytoavailability (DTPA-extractable Pb fraction) in soil and its uptake in plant shoots, roots, and grain, up to 61%, 83%, 74%, and 92%. The grain produced under APII−C + A. niger were safe for human consumption as Pb concentration in grain was 4.01 mg kg⁻¹ DW, remaining within the permissible limit set by WHO/FAO (2007). The APII−C + A. niger treatment also improved soil pH, EC, CEC, MBC, available P content and enzymatic activities, and the fenugreek quality parameters. A. niger played a significant role in solubilizing PO₄³⁻ from APII−C, which reacted with Pb and formed insoluble Pb-phosphates, thereby reducing Pb phytoavailability in PBS and its uptake in plants. This study suggests APII−C + A. niger can remediate Pb-polluted soils via reducing Pb phytoavailability in them.

Increasing amount of aluminum (Al) gets into aquatic ecosystem through anthropogenic activity, but the knowledge about Al migration and relationships with sediments possessing different physico-chemical properties in eutrophic lakes is limited. Here, the Al migration rule and relationships with sediment nutritions in the Hangzhou West Lake, China was investigated, where a certain amount of residual Al-salts can enter because of the pre-treatment of the Qiantang River diversion project every day. Results revealed the obvious spatial distribution heterogeneity of Al in sediment vertical direction and horizontal direction following water flow. The Al content in sediment ranged 0.463–1.154 g kg⁻¹ in Maojiabu Lake, and ranged 9.862–40.442 g kg⁻¹ in Xiaonanhu Lake. Higher Al content distributed in upper layer sediment in lake with more disturbance. Total nitrogen (TN) contents were higher 0.917–3.387 mg g⁻¹ and 0.627–0.786 mg g⁻¹ in upper layer sediment than that in lower layer in Maojiabu Lake and Xiaonanhu Lake, respectively. Total phosphorus (TP) content ranged 0.779–2.580 mg g⁻¹, in which IP and Fe/Al-P contributed 24.9–80.8% and 17.0–51.6%, respectively. Correlations between Al content with nutrition, humic acid (HA) etc. of sediment regionally varied in Maojiabu and Xiaonanhu Lake. Spatial distribution of Al-salt in eutrophic lakes closely related with the physico-chemical characteristics of nutrients, humus, human disturbance and water division parameters. Results provides new insight into Al-salts migration and references for Al-risk evaluating in eutrophic lakes.

Obesity and exposure to particular matter (PM) have become two leading global threats to public health. However, the exact mechanisms and tissue-specificity of their health effects are largely unknown. Here we investigate whether a metabolic challenge (early nutritional obesity) synergistically interacts with an environmental challenge (PM exposure) to alter genes representing key response pathways, in a tissue-specific manner. Mice subjected to 7 weeks obesogenic nutrition were exposed every other day during the final week and a half to aqueous extracts of PM collected in the city of London (UK). The expression of 61 selected genes representing key response pathways were investigated in lung, liver, white and brown adipose tissues. Principal component analysis (PCA) revealed distinct patterns of expression changes between the 4 tissues, particularly in the lungs and the liver. Surprisingly, the lung responded to the nutrition challenge. The response of these organs to the PM challenge displayed opposite patterns for some key genes, in particular, those related to the Nrf2 pathway. While the contribution to the variance in gene expression changes in mice exposed to the combined challenge were largely similar among the tissues in PCA1, PCA2 exhibited predominant contribution of inflammatory and oxidative stress responses to the variance in the lungs, and a greater contribution of autophagy genes and MAP kinases in adipose tissues. Possible involvement of alterations in DNA methylation was demonstrated by cell-type-specific responses to a methylation inhibitor. Correspondingly, the DNA methyltransferase Dnmt3a2 increased in the lungs but decreased in the liver, demonstrating potential tissue-differential synergism between nutritional and PM exposure. The results suggest that urban PM, containing dissolved metals, interacts with obesogenic nutrition to regulate diverse response pathways including inflammation and oxidative stress, in a tissue-specific manner. Tissue-differential effects on DNA methylation may underlie tissue-specific responses to key stress-response genes such as catalase and Nrf2.