环境科学与生态学最新文献

Formamide condensation with Ni can generate the NC structure, widely recognized as an efficient catalyst for electrocatalytic CO₂ reduction reaction (CO₂RR). To improve the utilization efficiency of Ni atoms, we introduced metal oxides as substrates to modulate the growth of a formamide-Ni (FA-Ni) condensate. FA-Ni@TiO₂ demonstrated 2.8 times higher partial CO current density and Ni turnover frequency than FA-Ni, which were also higher than those of other FA-Ni@metal oxides, including ZrO₂, Al₂O₃, Fe₂O₃, and ZnO. The improved performance of CO₂RR can be attributed to the Ni content exposed on FA-Ni@TiO₂ being twice that of the raw FA-Ni condensate. The Fourier transform infrared results suggested that formamide was adsorbed on TiO₂ via the -CHO group, exposing -NH₂ for potential interaction with Ni. As a result, Ni atoms were predispersed on the TiO₂ surface. By contrast, the dispersion of Ni atoms was not enhanced by other metal oxides, such as Al₂O₃, Fe₂O₃, and ZnO, owing to the robust acidity of their surface sites. These metal oxides adsorbed formamide via -NH₂, leading to the absence of extra -NH₂ available for binding to Ni atoms. This study provides new insights into the development of appropriate substrates for single-atom catalysts.

We coupled twenty-first century climate projections with a well-established water quality model to depict future ecological changes of Rappbode Reservoir, Germany. Our results document a chain of climate-driven effects propagating through the aquatic ecosystem and interfering with drinking water supply: intense climate warming (RCP8.5 scenario) will firstly trigger a strong increase in water temperatures, in turn leading to metalimnetic hypoxia, accelerating sediment nutrient release and finally boosting blooms of the cyanobacterium Planktothrix rubescens. Such adverse water quality developments will be suppressed under RCP2.6 and 6.0 indicating that mitigation of climate change is improving water security. Our results also suggested surface withdrawal can be an effective adaptation strategy to make the reservoir ecosystem more resilient to climate warming. The identified consequences from climate warming and adaptation strategies are relevant to many deep waters in the temperate zone, and the conclusion should provide important guidances for stakeholders to confront potential climate changes.

Spodoptera frugiperda is a significant agricultural pest, severely impacting the yield and quality of grain. Chitin is the momentous component of exoskeletons, which has a significant impact on the growth and development of insects. Our previous study found that exposure to lufenuron can reduce the expression of chitinase gene (SfCHT5) and increase the expression of chitin synthase gene (SfCHSB), two key genes for chitin synthesis in S. frugiperda. However, the post-transcriptional regulatory mechanisms of these key genes in S. frugiperda remain unclear. With miRNA as the entry point, target site prediction, dual luciferase reporter assays, and mimics/inhibitors injection were used to explore the post-transcriptional regulatory mechanism of SfCHSB and SfCHT5. The combined results confirm that miR-10482-5p targets SfCHT5 and regulates its expression, while miR-9a targets and regulates the expression of both SfCHT5 and SfCHSB. Additionally, injection of miR-10482-5p and miR-9a mimic significantly reduced the mortality rates of S. frugiperda treated with lufenuron, increased pupation rate, and emergence rate. These findings underscore the critical regulatory role of miR-10482-5p and miR-9a in modulating the expression of key genes involved in chitin synthesis, thereby enhancing the tolerance of S. frugiperda to lufenuron and influencing its growth and development. In summary, this study preliminarily elucidates the post-transcriptional regulatory mechanisms of miRNA-mediated SfCHSB and SfCHT5 expression.

Insecticide resistance in natural enemies can be used as a positive trait in integrated pest management programs by increasing the compatibility of two important tools; biological and chemical control. In this experiment, a field population of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) was selected with chlorantraniliprole for 35 generations (Chlor-Sel) developed a 100.32-fold resistance level compared to an unselected population (Unsel). The dominance values of resistance for reciprocal crosses confirmed incomplete dominance inheritance of chlorantraniliprole resistance. The results on projected rate of chlorantraniliprole resistance showed that at 10 % to 90 % survival in each selection and a realized heritability value of 0.19, the Chlor-Sel will require only 3 to 26 generations (Slope = 1.15) to increase a 10-fold level of resistance. The results of the age-stage life table experiment showed that fecundity, oviposition days, male and female longevity, net reproductive rate (Ro), and gross reproductive rate (GRR) of both crosses were significantly increased compared to their parents. The fecundity of reproductive females, male and female longevity, Ro, generation time (T), and GRR of Chlor-Sel were not significantly different than that of the Unsel strain of C. carnea. In conclusion, chlorantraniliprole resistance in C. carnea has an autosomal, polygenic, and incompletely dominant inheritance mode and C. carnea has potential to develop resistance that leads to fitness benefits. This information will help in management of insect pests by deploying resistant strains with selected insecticides and conservation of these natural enemies in fields with sustaining resistance genes.

Perfluorooctanoic acid (PFOA) and its substitute, hexafluoropropylene oxide dimer acid (GenX), are widely used perfluorinated compounds (PFCs) that pose significant risks to marine ecosystems. However, the specific impacts of these contaminants on marine invertebrates, particularly echinoderms, remain poorly understood. Strongylocentrotus intermedius, a globally significant benthic aquacultural species, may be potentially affected by PFCs. This study aimed to assess the reproductive toxicity of PFOA and GenX in S. intermedius. After exposing S. intermedius to either PFOA or GenX for 7 or 14 days, it was observed that even at environmentally relevant concentrations (2 μg/L), both compounds inhibited normal growth and gonadal development in S. intermedius, with effects becoming more pronounced over time. Further analysis revealed that prolonged exposure to PFCs resulted in a significant reduction in energy reserves (glycogen, lipids, and proteins) and caused abnormal changes in metabolic enzyme activities, with PFOA exhibiting more pronounced effects compared to GenX. At the genetic level, the expression of genes related to gonadal development initially increased and then decreased as the concentrations of the compounds rose. Additionally, integrated biomarker response analysis indicated that PFOA had greater reproductive toxicity than GenX, in terms of both concentration and exposure duration. These results provided a preliminary evaluation of the impact of PFCs on marine invertebrates, offering a foundation for further research into their ecological risks and contributing to the development of more comprehensive environmental risk assessments for these contaminants.

The toxic effects of long-term exposure to low doses of chlorpyrifos (CPF) on Eriocheir sinensis were evaluated using acute toxicity tests, transcriptome analyses, and metabolome profiling. Four groups (three replicates per group, 60 crabs)-control (no CPF exposure), high exposure (0.12 mg/L CPF), medium exposure (0.036 mg/L), and low exposure (0.012 mg/L)-were subjected to CPF for 21 days. Tissue damage, antioxidant enzyme activity, transcriptional changes, and metabolic alterations in E. sinensis were analyzed. The results demonstrated that CPF disrupted the regulatory networks of transcription and metabolism in crabs under the experimental concentration conditions, with the severity of effects increasing as the duration of exposure lengthened despite the crabs' efforts to activate key defense mechanisms, such as upregulation of cholinesterase 1-like gene expression, to counteract organophosphorus toxicity and adapt to CPF presence in their environment. Even at low concentrations (0.012 mg/L), neurobehavioral development and the antioxidant kinase system in crabs were impaired, leading to hepatopancreatic tissue lesions that negatively affect their growth and survival rates. Additionally, E. sinensis accumulates significant levels of CPF, which may pose food safety concerns when humans consume them. Therefore, ensuring the rational use of CPF requires maintaining appropriate water concentrations to minimize direct harm to aquatic organisms and indirect impacts on food safety associated with this pesticide.

Daphnia's antipredator responses are regulated largely by the nervous system, making these responses particularly susceptible to compounds that impact neurodevelopmental or neurofunctional processes. This study aimed to determine the molecular pathways involved in modulating the effects of scopolamine on inducible antipredation responses triggered by fish kairomones. We used two clones showing two contrasting responses. The positive phototactic clone 85 responds strongly to fish kairomones showing a marked negative phototactism and higher developmental rates. Consistently, the negative phototactic clone F shows the opposite behavior to the same stimuli. Adults of both clones were exposed to fish kairomones, scopolamine alone and a mixture of both. Scopolamine is a muscarine antagonist able to mimic fish kairomones inducible behavioral responses in both clones, while affecting differently morphological and life-history traits. Whole transcriptomic Illumina analyses indicated a greater number of de-regulated genes of the fish kairomone sensitive clone 85 (1650) compared to the F one (1138), which were grouped in four clusters (two per clone). The mixture of scopolamine and fish kairomone treatments on gene transcription was additive in both clones, indicating similar modes of action. Most enriched metabolic routes were related with neurological pathways and regulation of cell proliferation/differentiation. Our results indicate that fish kairomones and scopolamine deregulate not only neurological signaling pathways but also cell differentiation and proliferation pathways, which are linked to the observed behavioral responses as well as the developmental, morphological, and reproductive effects.

The skin and gut microbiota are crucial to amphibians. Triadimefon (TF), a widely used triazole fungicide, controls crop diseases and regulates growth, with uncertain effects on amphibian microbiota. Contamination, typically involving mixed chemicals at low concentrations, including cadmium (Cd) and TF, may detrimentally affect amphibian growth, survival, and microbiota health in both the skin and gut, but few research has examined these consequences. This research examines the impact of Cd and TF on Rana dybowskii tadpoles, focusing on survival, body mass, and microbiome changes over 28 days across four groups: control, Cd, TF, and Cd + TF groups. Results showed significant reductions in survival and body mass in Cd and TF-treated groups, with the combination group being the most affected. Microbiota analysis revealed significant dysbiosis in both gut and skin microbiomes under pollutant stress, with a marked microbiota and a shift in dominant microbial communities. Function prediction analysis based on the microbiome composition highlighted significant differences across various biological pathways, including metabolism, immune system, environmental adaptation, and disease resistance. These alterations suggest that pollutant exposure compromises the tadpoles' ability to maintain homeostasis and resist pathogens. In conclusion, this study reveals the detrimental effects of Cd and TF on the survival, growth, and microbiomes of R. dybowskii tadpoles, indicating significant environmental and health risks.