Endocrine disrupting chemicals (EDCs) can disrupt normal endocrine function by interfering with the synthesis and release of hormones, causing adverse reactions to development, immunity, nerves, and ...reproduction. 4-tert-Butylphenol (4-t-BP) is disruptive to early zebrafish development, but its effects on zebrafish liver are unknown. In this study, the adverse effects of 4-t-BP on the liver were investigated using zebrafish as a model organism. 4-t-BP inhibited liver development in zebrafish embryos and induced liver damage in adult zebrafish. Even if F1 was not directly exposed to 4-t-BP, its growth and development were inhibited. 4-t-BP can lead to an increase in lipid accumulation, total cholesterol and triglycerides contents, and the activities of alanine transaminase and aspartate aminotransferase in zebrafish embryos and adult zebrafish livers, and also cause an acceleration of glucose metabolism in zebrafish embryos. In addition, qRT-PCR showed that 4-t-BP induced the changes in the expressions of liver development-, steroid and unsaturated fatty acid biosynthesis-, and glycerolipid and arachidonic acid metabolism-related genes in zebrafish embryos and inflammatory factors-, antioxidant enzymes- and lipid metabolism-related genes in adult zebrafish livers. Transcriptome sequencing of embryos showed that 4-t-BP altered the expressions of lipid metabolism pathways such as steroid and unsaturated fatty acid biosynthesis, glycerolipid, and arachidonic acid metabolism pathways. Therefore, 4-t-BP may be external stimuli that cause oxidative stress, inflammation, and lipid accumulation in zebrafish liver, resulting in tissue damage and dysfunction in zebrafish liver.
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•4-t-BP inhibits the liver development of juvenile zebrafish and causes liver damage.•4-t-BP causes liver damage in adult zebrafish.•4-t-BP inhibits F1 growth and development.•4-t-BP induces lipid accumulation in zebrafish.•4-t-BP disrupts lipid metabolism pathway in zebrafish.
Summary
MYB transcription factors (TFs) have been demonstrated to play diverse roles in plant growth and development through interaction with basic helix‐loop‐helix (bHLH) TFs. MdbHLH33, an apple ...bHLH TF, has been identified as a positive regulator in cold tolerance and anthocyanin accumulation by activating the expressions of MdCBF2 and MdDFR. In the present study, a MYB TF MdMYB308L was found to also positively regulate cold tolerance and anthocyanin accumulation in apple. We found that MdMYB308L interacted with MdbHLH33 and enhanced its binding to the promoters of MdCBF2 and MdDFR. In addition, an apple RING E3 ubiquitin ligase MYB30‐INTERACTING E3 LIGASE 1 (MdMIEL1) was identified to be an MdMYB308L‐interacting protein and promoted the ubiquitination degradation of MdMYB308L, thus negatively regulated cold tolerance and anthocyanin accumulation in apple. These results suggest that MdMYB308L acts as a positive regulator in cold tolerance and anthocyanin accumulation in apple by interacting with MdbHLH33 and undergoes MdMIEL1‐mediated protein degradation. The dynamic change in MYB‐bHLH protein complex seems to play a key role in the regulation of plant growth and development.
Traffic-loaded areas have been of increasing concern due to the potential risk of carcinogenic pollutants, including antimony (Sb), which accumulates mostly in atmospheric particles (PM) and can ...interact with soil organic matter (Corg). The stability of Sb in topsoils was studied via the adsorption mechanism using standard soils and Corg-reach vehicle-produced particles as the unique source of “traffic” Sb. The mixed adsorbents were prepared from loamy sand and clay standard soils, and braking abrasion dust and diesel engine soot as Sb sources in atmospheric PM. Whereas the black carbon (BC), as part of Corg, disposes of exceptional adsorption properties compared to the other Corg, all adsorption experiments were performed identically on the adsorbents prepared from the original standard soils and Sb source materials and on the adsorbents prepared from the same materials annealed at 375 °C to ensure only BC participation in adsorption processes. The concentration of the Sb model solution corresponded to the average Sb content in rainwater from traffic-loaded localities. In addition to Sb, the Corg and iron (Fe) were monitored. The sorbability of Sb on the loamy sand soil mixtures increased up to 90% compared with the pure soil due to new active surface sites for Sb binding created due to the Corg added with the source material. The clay soil mixture containing 10 times more Corg compared with the loamy sand soil accumulated the Corg from the source material, which resulted in blocking active sites and a decline in Sb sorbability by up to 20%. The processes performed identically with original and annealed materials showed the same trends and confirmed the key role of BC and soil quality in the accumulation and stability of Sb in traffic-loaded topsoils. The participation of Fe in Sb surface interactions was not observed.
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•Antimony (Sb) near traffic nodes represents environmental risk due to growing automotive traffic.•Brake abrasion dust poses actual Sb risk through atmospheric particles (PM) and following infiltration into local topsoils.•Black carbon (BC) plays key role in Sb interaction with organic matter (OM) in soils and PM.•Stability of Sb near traffic nodes is entirely controlled by topsoil texture and BC content.
Silicon (Si) effectively promote the yield of many crops, mainly due to its ability to enhance plants resistance to stress. However, how Si helps hyperaccumulators to extract Cadmium (Cd) from soil ...has remained unclear. In this study, Sedum alfredii Hance (S. alfredii) was used as material to study how exogenous Si affected biomass, Cd accumulation, antioxidation, cell ultrastructure, subcellular distribution and changes in gene expression after Cd exposure. The study has shown that as Si concentration increases (1, 2 mM), the shoot biomass of plants increased by 33.1%–63.6%, the Cd accumulation increased by 31.9%–96.6%, and the chlorophyll, carotenoid content, photosynthetic gas exchange parameters significantly increased. Si reduced Pro and MDA, promoted the concentrations of SOD, CAT and POD to reduce antioxidant stress damage. In addition, Si promoted GSH and PC to chelate Cd in vacuoles, repaired damaged cell ultrastructure, improved the fixation of Cd and cell wall (especially in pectin), and reduced the toxic effects of Cd. Transcriptome analysis found that genes encoding Cd detoxification, Cd absorption and transport were up-regulated by Si supplying, including photosynthetic pathways (PSB, LHCB, PSA), antioxidant defense systems (CAT, APX, CSD, RBOH), cell wall biosynthesis such as pectinesterase (PME), chelation (GST, MT, NAS, GR), Cd absorption (Nramp3, Nramp5, ZNT) and Cd transport (HMA, PCR). Our result revealed the tentative mechanism of Si promotes Cd accumulation and enhances Cd tolerance in S. alfredii, and thereby provides a solid theoretical support for the practical use of Si fertilizer in phytoextraction.
Si can increases the biomass and Cd accumulation of S. alfredii, promotes plant photosynthesis and the fixation of Cd by pectin in cell walls, and up-regulates genes involved in plant Cd absorption and transport, thereby reducing Cd poisoning and improving the efficiency of Cd enrichment in S. alfredii. Display omitted
•Si increases plant biomass, Cd accumulation and photosynthesis.•Si alleviates the ultrastructural damage of cells, promotes the fixation of Cd by pectin in the cell wall.•Si up-regulates genes involved in plant Cd absorption and transport, promoting Cd absorption and accumulation.•Si regulates plant antioxidant enzymes and cell wall related genes to alleviates Cd toxicity.
Nanoparticles can be absorbed by plants, but their impacts on phytoremediation are not yet well understood. This study was carried out to determine the impacts of starch stabilized nanoscale ...zerovalent iron (S-nZVI) on the cadmium (Cd) accumulation and the oxidative stress in Boehmeria nivea (L.) Gaudich (ramie). Plants were cultivated in Cd-contaminated sediments amended with S-nZVI at 100, 500, and 1000 mg/kg, respectively. Results showed that S-nZVI promoted Cd accumulation in ramie seedlings. The subcellular distribution result showed that Cd content in cell wall of plants reduced, and its concentration in cell organelle and soluble fractions increased at S-nZVI treatments, indicating the promotion of Cd entering plant cells by S-nZVI. In addition, the 100 mg/kg S-nZVI alleviated the oxidative damage to ramie under Cd-stress, while 500 and 1000 mg/kg S-nZVI inhibited plant growth and aggravated the oxidative damage to plants. These findings demonstrate that nanoparticles at low concentration can improve the efficiency of phytoremediation. This study herein develops a promising novel technique by the combined use of nanotechnology and phytoremediation in the remediation of heavy metal contaminated sites.
The accumulation of short-chain fatty acids (SCFAs), a preferred carbon source for enhanced biological phosphorus removal microbes, was significantly improved when waste activated sludge (WAS) was ...fermented at pH 10. The kinetics of WAS hydrolysis and SCFAs production at pH 10 was investigated. It was observed that during WAS anaerobic fermentation the accumulation of SCFAs was limited by the hydrolysis process, and both the hydrolysis of WAS particulate COD and the accumulation of SCFAs followed first-order kinetics. The hydrolysis and SCFAs accumulation rate constants increased with increasing temperature from 10 to 35C, which could be described by the Arrhenius equation. The kinetic data further indicated that SCFAs production at pH 10 was a biological process. Compared with the experiment of pH uncontrolled (blank test), both the rate constants of WAS hydrolysis and SCFAs accumulation at 20C were improved significantly when WAS was fermented at pH 10.
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•Syntrophic associations were enriched to relieve acid accumulation.•Fatty acid-oxidizing syntrophs and H2/formate-utilizing methanogens were enriched.•Enriched syntrophic ...associations favored degradation of propionate and butyrate.•The interspecies formate/hydrogen transfer was enhanced with microbial enrichment.
Aiming at relieving acid accumulation in anaerobic digestion (AD), syntrophic associations of syntrophic fatty acid-oxidation bacteria and H2/formate-scavenging methanogens were enriched by feeding propionate, butyrate and formate in an up-flow anaerobic sludge blanket (UASB) reactor. Results showed that methane yield increased by 50% with increasing formate concentration (0–2000 mg COD/L). In addition, the abundance and quantity of SFOB (Syntrophobacter, Smithella and Syntrophomonas) and H2/formate-scavenging methanogens (Methanobacteriales and Methanomicrobiales) were increased after microbial acclimation. The enriched syntrophic associations showed higher propionate and butyrate removal efficiencies of 98.48 ± 1.14% and 99.71 ± 0.71%, respectively. Furthermore, encoding genes of formate dehydrogenase and hydrogenases presented higher abundances after microbial enrichment, which suggested that the enhancements of interspecies formate transfer and interspecies hydrogen transfer between syntrophic associations benefited volatile fatty acids (VFAs) conversion. This research provided an effective strategy to relieve acid accumulation.
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•Novel characteristics of Fe(0)-ADN with aeration were revealed.•Opportune DO (1.6 ± 0.1 mg/L) enhanced Fe(0)-ADN and reduced N2O/NO2− accumulation.•Bioconversion of Fe3O4 into ...FeO(OH) was enhanced and benefitted H2/Fe2+ generation.•Genes napA, nirK & nosZ, and enzymes NAP, NIR & NosZ maintained aerobic Fe(0)-ADN.•Iron-scraps is potential as the Fe(0)-source under the mediation of micro-electrolysis.
This study revealed novel characteristics of the Fe(0)-oxidizing autotrophic denitrification Fe(0)-ADN process with aeration, including nitrogen removal efficiency, electron donor transformation, N2O/NO2− accumulation, and variation of microbial communities and functional genes/enzymes. Iron-scraps (ISs) was utilized as Fe(0) source under the mediation of micro-electrolysis for ISs-ADN process establishment. The anaerobic ISs-ADN process achieved an initial denitrification load of 0.12 ± 0.02 kgN/(m3·d), and it subsequently shifted to 0.34 ± 0.01 kgN/(m3·d) when dissolved oxygen (DO) was increased from 0.1 ± 0.1 mg/L to 1.6 ± 0.1 mg/L. Significant accumulations of N2O (0.9 ± 0.2 mgN2O-N/L) and NO2− (5.5 ± 0.7 mgNO2−-N/L) were observed in the anaerobic ISs-ADN system, they were reduced to 0.07 ± 0.02 mgN/L and 0.2 ± 0.2 mgN/L, respectively, at DO of 1.6 ± 0.1 mg/L. X-ray diffraction spectra showed that oxygen could enhance bioconversion of Fe3O4 into FeO(OH) and reduce the Fe(0)-coating by Fe3O4, and hence enhance the ME process for H2/Fe2+ production. High-throughput sequencing results showed that iron-compound transformation bacteria (e.g. Sphaerotillus) and facultative autotrophic denitrificans (e.g. Hydrogenophaga) were enriched at higher DO of 1.6 ± 0.1 mg/L. Genes napA (encoding NAP), nirK (encoding NIR) and nosZ (encoding NosZ) exhibited higher oxygen tolerance. Enzymes NAP, NIR and NosZ maintained the aerobic denitrification, and NIR and NosZ inhibited the accumulation of N2O and NO2−, respectively. Exorbitant aeration (DO ≥ 2.2 ± 0.2 mg/L) accelerated iron oxidation to Fe3O4 on the ISs surface and restrained ISs-ADN. This study provides an in-depth understanding on the impact of oxygen on the Fe(0)-ADN. The micro-electrolysis mediated ISs-ADN is competitive in both efficiency and cost with the utilization of ISs.
In this article we analyse and theorise how power is exercised and subjectivities reworked to achieve and maintain socio‐political order in areas of large‐scale international extractive investment. ...Through a critical review of recent literature on the political ecologies of the international mining and hydrocarbon industries, we explore the strategies that firms and their allies deploy to secure and preserve the transformed relations of land and resource access upon which accumulation relies. Inspired by the work of John Allen we analyse these strategies with attention to the modalities and techniques of power used, highlighting the diverse ways socio‐political stability is pursued despite the industry’s destabilising effects. What emerges is that, contrasting the sector’s reputation for coercion and domination, transformed regimes of access to land and resources at the extractive frontier are to a significant degree achieved and stabilised through what Allen calls the “quieter registers” of power. Attention to the varied and overlapping ways extractive firms and their allies exercise power to secure and maintain access to land and resources highlights limitations to David Harvey’s influential accumulation by dispossession framework for understanding how extractive capital circulates into “new ground.” It also directs attention to processes of subject formation at the extractive frontier, and to how industry expansion may be facilitated through the production of particular kinds of subjects. To illustrate this, we outline three interrelated ways subjectivities are reworked through peoples’ encounters with the logics, materiality, and power of contemporary extractive industry. We suggest that those living in the shadow of large international extractive operations become extractive subjects.
This article reviews recent critical social science research on extractive industry to examine and theorise the relationship between land and resource access, techniques of power, and subject formation. Reviewing this literature reveals the range of strategies deployed to achieve the forms of asset redistribution on which extractive industry's development depends and to address the socio‐political tumult often generated. Attention to the varied ways extractive firms and their allies exercise power to secure and maintain access to land and resources highlights limitations to David Harvey's influential accumulation by dispossession framework and directs attention to how industry expansion is facilitated through the production of particular kinds of subjects.
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