Display omitted
•Differentially charged PS-NP accumulated in brain of zebrafish larvae.•PS-NH2 induced more serious cell apoptosis in brain than PS-COOH.•13 altered metabolites related to NMDA2B in ...PS-NH2 exposure.•3 changed metabolites related to GPRs were increased by PS-COOH exposure.•Stronger binding between NMDA2B with PS-NH2 than PS-COOH affected behaviors.
Nanoplastics are being detected with increasing frequency in aquatic environments. Although evidence suggests that nanoplastics can cause overt toxicity to biota across different trophic levels, but there is little understanding of how materials such as differently charged polystyrene nanoplastics (PS-NP) impact fish development and behavior. Following exposure to amino-modified (positive charge) PS-NP, fluorescence accumulation was observed in the zebrafish brain and gastrointestinal tract. Positively charged PS-NP induced stronger developmental toxicity (decreased spontaneous movement, heartbeat, hatching rate, and length) and cell apoptosis in the brain and induced greater neurobehavioral impairment as compared to carboxyl-modified (negative charge) PS-NP. These findings correlated well with fluorescence differences indicating PS-NP presence. Targeted neuro-metabolite analysis by UHPLC-MS/MS reveals that positively charged PS-NP decreased levels of glycine, cysteine, glutathione, and glutamic acid, while the increased levels of spermine, spermidine, and tyramine were induced by negatively charged PS-NP. Positively charged PS-NP interacted with the neurotransmitter receptor N-methyl-D-aspartate receptor 2B (NMDA2B), whereas negatively charged PS-NP impacted the G-protein-coupled receptor 1 (GPR1), each with different binding energies that led to behavioral differences. These findings reveal the charge-specific toxicity of nanoplastics to fish and provide new perspective for understanding PS-NP neurotoxicity that is needed to accurately assess potential environmental and health risks of these emerging contaminants.
With their growing production and application, engineered nanoparticles (NPs) are increasingly discharged into the environment. The released NPs can potentially interact with pre-existing ...contaminants, leading to biological effects (bioaccumulation and/or toxicity) that are poorly understood. Most studies on NPs focus on single analyte exposure; the existing literature on joint toxicity of NPs and co-existing contaminants is rather limited but beginning to develop rapidly. This is the first review paper evaluating the current state of knowledge regarding the joint effects of NPs and co-contaminants. Here, we review: (1) methods for investigating and evaluating joint effects of NPs and co-contaminants; (2) simultaneous toxicities from NPs co-exposed with organic contaminants, metal/metalloid ions, dissolved organic matter (DOM), inorganic ligands and additional NPs; and (3) the influence of NPs co-exposure on the bioaccumulation of organic contaminants and heavy metal ions, as well as the influence of contaminants on NPs bioaccumulation. In addition, future research needs are discussed so as to better understand risk associated with NPs-contaminant co-exposure.
Due to their well-known antifungal activity, the intentional use of silver nanoparticles (AgNPs) as sustainable nanofungicides is expected to increase in agriculture. However, the impacts of AgNPs on ...plants must be critically evaluated to guarantee their safe use in food production. In this study, 4-week-old cucumber (Cucumis sativus) plants received a foliar application of AgNPs (4 or 40 mg/plant) or Ag+ (0.04 or 0.4 mg/plant) for 7 days. Gas chromatography–mass spectrometry (GC-MS)=based nontarget metabolomics enabled the identification and quantification of 268 metabolites in cucumber leaves. Multivariate analysis revealed that all the treatments significantly altered the metabolite profile. Exposure to AgNPs resulted in metabolic reprogramming, including activation of antioxidant defense systems (upregulation of phenolic compounds) and downregulation of photosynthesis (upregulation of phytol). Additionally, AgNPs enhanced respiration (upregulation of tricarboxylic acid cycle intermediates), inhibited photorespiration (downregulation of glycine/serine ratio), altered membrane properties (upregulation of pentadecanoic and arachidonic acids, downregulation of linoleic and linolenic acids), and reduced inorganic nitrogen fixation (downregulation of glutamine and asparagine). Although Ag ions induced some of the same metabolic changes, alterations in the levels of carbazole, lactulose, raffinose, citraconic acid, lactamide, acetanilide, and p-benzoquinone were AgNP-specific. The results of this study offer new insight into the molecular mechanisms by which cucumber responds to AgNP exposure and provide important information to support the sustainable use of AgNPs in agriculture.
Display omitted
•nTiO2 at a low concentration enhanced nutritional quality of coriander.•nTiO2 did not change the nutrient spatial distribution in coriander leaves.•no nTiO2 accumulation in edible ...parts suggests minimal risk to food safety.•nTiO2 at a high concentration may damage the root cell membrane and inhibit growth.
TiO2 nanoparticles (nTiO2) have been widely used in many disciplines. However, whether they can be used to improve crops growth and nutritional quality is unknown. In this study, coriander (Coriandrum sativum L.) was treated with 0, 50, 100, 200, and 400 mg/L nTiO2 to evaluate their possible benefit to plant growth and nutritional quality under hydroponic conditions. Our observations showed that 50 mg/L nTiO2 only slightly but insignificantly increased the root and shoot fresh biomass by 13.2 % and 4.1 %, respectively, relative to the control. nTiO2 at this level promoted shoot K, Ca, Mg, Fe, Mn, Zn, and B accumulation, while spatial distribution of K, Ca, Fe, Mn, Cu and Zn in coriander leaves was not affected. No nTiO2 internalization or translocation to shoots occurred. 400 mg/L nTiO2 significantly reduced root fresh biomass by 15.8 % and water content by 6.7 %. Moreover, this high dose induced root cell membrane wrinkling, attributable to their aggregation and adsorption on root surfaces. At 100–400 mg/L, antioxidant defense systems (SOD, CAT and APX) in plant were triggered to alleviate oxidative stress. At an appropriate dose (50 mg/L), nTiO2 can improve nutrient quality of edible tissues without exerting toxicity to plant or posing health risk to consumers.
Virtual memory cells (VM) are an antigen-specific, memory phenotype CD8 T-cell subset found in lymphoreplete, unchallenged mice. Previous studies indicated that VM cells were the result of ...homeostatic proliferation (HP) resembling the proliferation observed in a lymphopenic environment. Here we demonstrate that HP is ongoing in lymphoreplete mice, the degree of which is dictated by the number of naive CD8 T cells with a sufficiently high affinity for self-antigen interacting with peripheral IL-15. VM cell transcriptional profiles suggest a capacity to mediate protective immunity via antigen non-specific bystander killing, a function we show is dependent on IL-15. Finally, we show a VM-like population of human cells that accumulate with age and traffic to the liver, displaying phenotypic and functional attributes consistent with the bystander protective functions of VM cells identified in the mouse. These data identify developmental and functional attributes of VM cells, including their likely role in protective immunity.
Microplastics (MPs) contamination of marine environments poses a significant ecological risk, although impacts on species’ realized niche spaces remain unclear. The current study investigates MPs ...distribution across pelagic habitats, benthic sediments, and key biota in the South Yellow Sea, China. Samples were collected via trawling across estuarine transects, and tissues were digested to extract MPs. Density gradient separations and vacuum-filtrations prepared particle extracts for ATR-FTIR and Micro-Raman spectroscopic characterization. Sampling along industrialized river transects reveals ubiquitous plastic particle presence, with concentrations ranging from 0 to 51.68 item/L seawater. Contamination levels reach their peak at station estuaries before dispersing offshore, indicating significant waste stream inputs. Importantly, MPs detected in demersal and pelagic fish species, as well as in bivalves, confirm exposure across trophic niches. Gastrointestinal tract and gill concentrations reached 0.6 items/g fresh tissue, reflecting significant biological uptake and in vivo retention. The greatest population of organisms occurred adjacent to polluted areas. Overall, distribution of MPs from polluted rivers to coastal food webs was evident, suggesting potential negative impacts on key ecological functions in this system. These findings underscore the need to develop upstream mitigation efforts so as to minimize MPs contamination in areas where nearshore and offshore niches intersect.
Display omitted
•MPs ubiquitous in S. Yellow Sea, peak near industrial estuaries, decrease offshore.•Plastics in pelagic & benthic habitats, fish, bivalves indicate trophic transfer.•Proximity to pollution sources increases species' microplastic exposure risk.•Persistent MPs may alter marine niches long-term, displace adapted species.•MPs may disrupt finely-tuned niches, displace habitat-dependent species.
Plant diseases caused by microbial pathogens significantly reduce agriculture productivity and worsen food insecurity. Recently, Qiu et al. revealed that polyethyleneimine (PEI)-coated MXene quantum ...dots (QDs) improve tolerance in cotton seedlings against Verticillium wilt disease by maintaining oxidative system homeostasis. This finding shows how customized QDs can be used to enhance crop disease resistance.
Plant diseases caused by microbial pathogens significantly reduce agriculture productivity and worsen food insecurity. Recently, Qiu et al. revealed that polyethyleneimine (PEI)-coated MXene quantum dots (QDs) improve tolerance in cotton seedlings against Verticillium wilt disease by maintaining oxidative system homeostasis. This finding shows how customized QDs can be used to enhance crop disease resistance.
Two copper nanomaterials (CuO nanoparticles NPs and Cu3(PO4)2·3H2O nanosheets) and CuSO4 were applied to tomato (Solanum lycopersicum) leaves, and elemental Cu movement from the leaf surface through ...the cuticle and into the interior leaf tissue was monitored over 8 h. Two forms of nanoscale Cu were used to foliar treat tomato on a weekly basis in greenhouse and field experiments in the presence of the pathogen Fusarium oxysporum f. sp. lycopersici. For CuSO4, Cu accumulation and retention in the cuticle was over 7-fold greater than the nanomaterials, demonstrating that nanoscale morphology and composition mediate Cu accumulation in leaf tissue. In the greenhouse, weekly foliar applications of the nanosheets and NPs increased seedling biomass by 90.9 and 93.3%, respectively, compared to diseased and ionic Cu controls. In the field, Cu3(PO4)2·3H2O nanosheets reduced disease progress by 26.0% and significantly increased fruit yield by over 45.5% per plant relative to the other treatments in diseased soil. These findings suggest that nanoscale nutrient chemical properties can be tuned to maximize and control movement through the cuticle and that interactions at the seedling leaf biointerface can lead to season-long benefit for tomato growing in the presence of Fusarium spp.
Display omitted
► Exposure to different nanoparticles resulted in specific changes in gene transcription. ► Nano ZnO caused most dramatic changes in Arabidopsis gene expression. ► Nano ZnO was the ...most toxic and up-regulated most stress-related genes. ► Fullerene soot caused significant gene expression response – mainly stress-related. ► Nano TiO2 had weak impact on Arabidopsis gene expression indicating minimal toxicity.
The effect of exposure to 100mg/L zinc oxide (nZnO), fullerene soot (FS) or titanium dioxide (nTiO2) nanoparticles on gene expression in Arabidopsis thaliana roots was studied using microarrays. After 7d, nZnO, FS, or nTiO2 exposure resulted in 660 up- and 826 down-regulated genes, 232 up- and 189 down-regulated genes, and 80 up- and 74 down-regulated genes, respectively (expression difference>2-fold; pt test<0.05). The genes induced by nZnO and FS include mainly ontology groups annotated as stress responsive, including both abiotic (oxidative, salt, water deprivation) and biotic (wounding and defense to pathogens) stimuli. The down-regulated genes upon nZnO exposure were involved in cell organization and biogenesis, including translation, nucleosome assembly and microtubule based process. FS largely repressed the transcription of genes involved in electron transport and energy pathways. Only mild changes in gene expression were observed upon nTiO2 exposure, which resulted in up- and down-regulation of genes involved mainly in responses to biotic and abiotic stimuli. The data clearly indicate that the mechanisms of phytotoxicity are highly nanoparticle dependent despite of a limited overlap in gene expression response.
The use of nanomaterials in agriculture as nanofertilizers, nanopesticides, or nano-enabled sensors to increase crop yield is gaining increasing interest. Engineered nanomaterials (ENMs) can improve ...crop productivity by influencing fertilizer nutrient availability in soil and uptake by plants. These materials can suppress crop diseases by directly acting on pathogens through a variety of mechanisms, including the generation of reactive oxygen species (ROS). ENMs may also suppress disease indirectly by improving crop nutrition and enhancing plant defense pathways. Efficient use of ENMs may complement or replace conventional fertilizers and pesticides, subsequently reducing the environmental impact of agricultural practices. This review evaluates the current literature on ENMs used as pesticides and fertilizers, and highlights critical knowledge gaps that must be addressed to ensure sustainable application of nanotechnology in agriculture so as to achieve global food security.
The use of nanomaterials in agriculture as nanofertilizers, nanopesticides, or nano-enabled sensors to increase crop yield is gaining increasing interest.
PDF
