Glandless cotton can be grown to obtain cotton seeds free of toxic gossypol for use as both food and feed. However, they are not grown normally due to their lesser productivity and higher susceptibility to biotic stress. Great attention has been paid to biotic stresses rather than abiotic stresses on glandless cotton. Chromium (Cr) is a common pollutant of soil and considered a serious threat to plants due to its adverse effects on different functions. Although numerous studies are available on the toxicity of Cr⁶⁺ in various plants. However, its adverse effects and mechanism of toxicity in glandless cotton can seldom be found in the literature. This study examined the Cr⁶⁺ effect on glandless cotton in comparison to glanded cotton. Four pairs of glanded and glandless cotton near-isogenic lines (NILs) were exposed to different doses (0, 10, 50, and 100 μM/L) of Cr⁶⁺ for seven days, and biochemical, physiological, molecular, and ultrastructure changes were observed, which were significantly affected by Cr⁶⁺ at high concentrations in all NILs. The effect of Cr⁶⁺ on ionic contents shows the same trend in glanded and glandless NILs except for manganese (Mn²⁺) that show inhibition in glandless (ZMS-12w and Coker-312w) and enhance in the glanded NIL (ZMS-17). The gene expression of superoxide dismutase (SOD) and peroxidase (POD) revealed similar trends as enzyme activities in glandless NILs. The principal component analysis (PCA) and Agglomerative hierarchical clustering (AHC) results of all NILs from morpho-physiological traits, cluster ZMS-16, and ZMS-17 into Cr⁶⁺ sensitive group. While the glandless NILs have the potential to cope with the Cr toxicity by increasing the antioxidant enzyme activity and their gene expression. This study also revealed that Cr⁶⁺ tolerance in cotton is genotypic and has an independent mechanism in the root that not related to low gossypol.

With the induction of various emerging environmental contaminants such as antibiotic resistance genes (ARGs), environment is considered as a key indicator for the spread of antimicrobial resistance (AMR). As such, the ARGs mediated environmental pollution raises a significant public health concern worldwide. Among various genetic mechanisms that are involved in the dissemination of ARGs, integrons play a vital role in the dissemination of ARGs. Integrons are mobile genetic elements that can capture and spread ARGs among environmental settings via transmissible plasmids and transposons. Most of the ARGs are found in Gram-negative bacteria and are primarily studied for their potential role in antibiotic resistance in clinical settings. As one of the most common microorganisms, Escherichia coli (E. coli) is widely studied as an indicator carrying drug-resistant genes, so this article aims to provide an in-depth study on the spread of ARGs via integrons associated with E. coli outside clinical settings and highlight their potential role as environmental contaminants. It also focuses on multiple but related aspects that do facilitate environmental pollution, i.e. ARGs from animal sources, water treatment plants situated at or near animal farms, agriculture fields, wild birds and animals. We believe that this updated study with summarized text, will facilitate the readers to understand the primary mechanisms as well as a variety of factors involved in the transmission and spread of ARGs among animals, humans, and the environment.

There is growing global awareness of the presence and negative impacts of waste plastic in the marine environment. Risks to wildlife include ingestion and entanglement for macro-plastic (larger than 5 mm in length), alongside food chain transfer for micro-plastics (less than 5 mm in length). Plastics in the marine environment have also been shown to adsorb and accumulate contaminants from seawater, e.g., heavy metals and hydrophobic organic compounds. This means that plastics can additionally act as vectors for transport of contaminants, permitting ecotoxicological risks to be spatially extended. However, the ability of waste plastic to adsorb pollutants also offers potential opportunity, if they can be used for the decontamination of wastewater. Here, we provide an overview of marine plastic types and distribution, and then systematically assess their potential to be repurposed as novel adsorbents. Data published in recent years are interrogated to gain an overview of the interaction mechanisms between marine plastics and both organic and inorganic contaminants. In addition, factors that may be exploited to enhance their performance in removal of contaminants are also reviewed and prioritised, e.g., surface modification and activation. This paper highlights the novel potential of repurposing plastic waste for wastewater treatment applications and seeks to identify key knowledge gaps and future research priorities for scientists and engineers.

Manganese (Mn) is an essential trace element, but an excess or accumulation can be toxic. Until now, few studies have examined the effects of maternal Mn level on the risk of spontaneous preterm birth (SPB). The aims of this study were to examine the association between maternal Mn level and the risk of SPB at the early stage of pregnancy, and investigate whether this association was modified by single nucleotide polymorphisms (SNPs) in genes of superoxide dismutase (SOD) and catalase (CAT). We conducted a nested case-control study in three maternal and child health care hospitals in Shanxi province, China, from December 2009 to December 2013. From an overall cohort of 4229 women, 528 were included in our study, including 147 cases of SPB and 381 controls. Maternal blood samples were collected during 4–22 gestational weeks. The maternal serum concentrations of Mn was measured using inductively coupled plasma–mass spectrometry. We found the maternal Mn concentration in the case group (median: 1.55 ng/mL) was significantly higher than that in the control group (median: 1.27 ng/mL). Compared to the lowest level, the SPB risk was significantly increased to 1.44 (95%CI: 0.60–3.43), 2.42 (95%CI: 1.06–5.55) and 2.46 (95%CI: 1.08–5.62) respectively for the second, third and fourth quartiles in first trimester, but not significant in second trimester or overall. When exposure to a high Mn level, women who with AA (6.36, 95%CI: 1.57–25.71) and AG (3.04, 95%CI: 1.59–5.80) of rs2758352, with CC (2.34, 95%CI: 1.31–4.18) of rs699473, and with GG (2.26, 95%CI: 1.22–4.16) of rs769214 were more likely to develop a SPB, but not among women with other genotypes. In conclusion, high maternal serum Mn level is associated with the increased SPB risk in first trimester, and the association is modified by maternal SNPs of SOD2, SOD3 and CAT.

A major health scandal involving DEHP-tainted (di-2-ethylhexyl phthalate) foodstuffs occurred in Taiwan in 2011. We investigated temporal relationships between urinary DEHP metabolites and biomarkers of oxidative stress in two cohorts of potentially affected children during that food scandal. One cohort was collected from Kaohsiung Medical University Hospital in southern Taiwan between May and June of 2011 (the KMUH cohort). This cohort was followed up at 2, 6, and 44 months. The other cohort was collected from a nationwide health survey conducted by Taiwan’s National Health Research Institutes (the NHRI cohort) for potentially affected people between August 2012 and January 2013. Both cohorts only included children 10 years old and younger who had provided enough urine for analysis of urinary DEHP oxidative metabolites and two markers of oxidative stress: 8-oxo-2′-deoxyguanosine (8-OHdG) and malondialdehyde (MDA). The KMUH cohort had a simultaneous and significant decrease in urinary DEHP metabolites, 8-OHdG, and MDA, with the lowest concentrations found at the 6-month follow up and maintained until the 44-month follow up, consistent with those from NHRI cohort at ∼15–18 months post-scandal (p > 0.05). There were decreases in both DEHP metabolites and oxidative stress markers across the populations, but no association was observed between DEHP metabolites and oxidative stress markers in individuals in the two cohorts. Continued follow-up is needed to determine long-term health consequences in these children.

Aerobic performance in fish is linked to individual and population fitness and can be impacted by anthropogenic contaminants. Exposure to some engineered nanomaterials, including silver nanoparticles (nAg), reduces rates of oxygen consumption in some fish species, but the underlying mechanisms remain unclear. In addition, their effects on swim performance have not been studied. Our aim was to quantify the impact of exposure to functionalized nAg on aerobic scope and swim performance in rainbow trout (Oncorhychus mykiss) and to characterize the contribution of changing rates of protein synthesis to these physiological endpoints. Fish were exposed for 48 h to 5 nm polyvinylpyrolidone-functionalized nAg (nAgPVP; 100 μg L⁻¹) or 0.22 μg L⁻¹ Ag⁺ (as AgNO₃), which was the measured quantity of Ag released from the nAgPVP over that time period. Aerobic scope, critical swimming speed (Ucᵣᵢₜ), and fractional rates of protein synthesis (Kₛ), were then assessed, along with indicators of osmoregulation and cardiotoxicity. Neither nAgPVP, nor Ag⁺ exposure significantly altered aerobic scope, its component parts, or swim performance. Kₛ was similarly unaffected in 8 tissue types, though it tended to be lower in liver of nAgPVP treated fish. The treatments tended to decrease gill Na⁺/K⁺-ATPase activity, but effects were not significant. The latter results suggest that a longer or more concentrated nAgPVP exposure may induce significant effects. Although this same formulation of nAgPVP is bioactive in other fish, it had no effects on rainbow trout under the conditions tested. Such findings on common model animals like trout may thus misrepresent the safety of nAg to more sensitive species.

A novel denitrifying bacterium YSF15 was isolated from the Lijiahe Reservoir in Xi’an and identified as Comamonas sp. It exhibited excellent nitrogen removal ability under low C/N conditions (C/N = 2.5) and 94.01% of nitrate was removed in 18 h, with no accumulation of nitrite. PCR amplification and nitrogen balance experiments were carried out, showing that 68.92% of initial nitrogen was removed as gas products and the nitrogen removal path was determined to be NO3−-N→NO2−-N→NO→N2O→N2. Scanning electron microscopy and three-dimensional fluorescence spectroscopy were used to track extracellular polymeric substances (EPS). The results show that complete-denitrification under low C/N conditions is associated with EPS, which may provide a reserve carbon source in extreme environments. These findings reveal that Comamonas sp. YSF15 can provide novel basic materials and a theoretical basis for wastewater bioremediation under low C/N conditions.

Copper is known to interfere with fish olfaction. Although the chemosensory detection and olfactory toxicity of copper ions (Cu²⁺) has been heavily studied in fish, the olfactory-driven detection of copper nanoparticles (CuNPs)—a rapidly emerging contaminant to aquatic systems—remains largely unknown. This study aimed to investigate the olfactory response of rainbow trout to equitoxic concentrations of CuNPs or Cu²⁺ using electro-olfactography (EOG, a neurophysiological technique) and olfactory-mediated behavioural assay. In the first experiment, the concentration of contaminants known to impair olfaction by 20% over 24 h (EOG-based 24-h IC20s of 220 and 3.5 μg/L for CuNPs and Cu²⁺, respectively) were tested as olfactory stimuli using both neurophysiological and behavioural assays. In the second experiment, to determine whether the presence of CuNPs or Cu²⁺ can affect the ability of fish to perceive a social cue (taurocholic acid (TCA)), fish were acutely exposed to one form of Cu-contaminants (approximately 15 min). Following exposure, olfactory sensitivity was measured by EOG and olfactory-mediated behaviour within a choice maze was recorded in the presence of TCA. Results of neurophysiological and behavioural experiments demonstrate that rainbow trout can detect and avoid the IC20 of CuNPs. The IC20 of Cu²⁺ was below the olfactory detection threshold of rainbow trout, as such, fish did not avoid Cu²⁺. The high sensitivity of behavioural endpoints revealed a lack of aversion response to TCA in CuNP-exposed fish, despite this change not being present utilizing EOG. The reduced response to TCA during the brief exposure to CuNPs may be a result of either olfactory fatigue or blockage of olfactory sensory neurons (OSNs) by CuNPs. The observed behavioural interference caused by CuNP exposure may indicate that CuNPs have the ability to interfere with other behaviours potentially affecting fitness and survival. Our findings also revealed the differential response of OSNs to CuNPs and Cu²⁺.

The interference of nonylphenol (NP) with humans and animals, especially in hormone systems, has been well-studied. There is rarely any record of its effect on bacteria, which dominate in various environments. In our study, we employed Pseudomonas aeruginosa PAO1 as a model microorganism and took its common lifestyle biofilm, mainly regulated by quorum sensing (QS), as a cut-in point to investigate the effect of NP (1, 5, 10 mg L⁻¹) on bacteria. The results showed that more than 5 mg L⁻¹ of NP did interfere with biofilm formation and affected bacterial QS. In detail, the LasI/R circuit, but not the RhlI/R circuit, was considerably obstructed. The decrease in lasI and lasR expression resulted in a significant reduction in N-3-oxo-dodecanoyl homoserine lactone (3OC₁₂-HSL) signals and the downstream production of elastases. Docking results indicated the binding of NP with LasR protein, simulating the binding of 3OC₁₂-HSL with LasR protein, which explained the obstruction of the LasIR circuit. We concluded that NP competed with 3OC₁₂-HSL and blocked 3OC₁₂-HSL binding with the LasR protein, resulting in a direct interference in bacterial biofilm formation. This is the first report of NP interference with bacterial signaling, which is not only helpful to understand the effect of NP on various ecosystems, but is also beneficial to enrich our knowledge of inter-kingdom communication.

Heavy metal contamination is a serious environmental problem commonly monitored in various organisms. Small wild rodents are ideal biological monitors to show the extent of environmental pollution. The aim of this study was to evaluate the adverse effects of marble and stone quarries on the Levant vole, Microtus guentheri, inhabiting some polluted sites. In this context, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to analyze distribution of thirteen heavy metals (Fe, Al, Zn, Cu, Cr, Mn, Ni, B, Pb, As, Co, Cd, and Hg) in the organs (skins, bones, muscles, livers and kidneys) of the biological specimens, and the comet assay revealed DNA damage in blood lymphocytes for the first time. This study was conducted at close to the marble and stone quarries at Korkuteli, Antalya-Turkey during spring, summer, autumn (2017) and winter (2018) seasons. In spring and summer, genetic damage in blood lymphocytes from all polluted sites (sites 1–5) was significantly higher than that of controls, while in autumn it was higher in samples from three sites (sites 3–5). In terms of heavy metal distribution in organs, we found depositions of Fe, Al, Zn, Ni, Mn, Cr, Co, As and Pb primarily in the skin with its derivatives, Cu and Cd deposits in the kidney, Cu, Cd and B deposits in the liver, and As and Pb depositions in the bones. The study shows that certain organs (especially skin with its derivatives) and blood lymphocytes of Levant vole can be used as ideal indicators of heavy metal pollution. Our results suggest that the Korkuteli area could already be under the threat of heavy metal pollution.