Biotoxicity responses of zebrafish in environmentally relevant concentration of di (2-ethylhexyl) phthalate.

As an emerging environmental contaminant, di (2-ethylhexyl) phthalate (DEHP) is widely present in the aquatic environment, however, the effects and underlying mechanisms of DEHP on the aquatic organisms are poorly understood. This study systematically investigated the ecotoxicity induced by chronic exposure to environmental relevant concentrations of DEHP (0.03 mg/L, 0.1 mg/L, and 0.3 mg/L) on zebrafish brain. Results indicated that DEHP exposure significantly increased the levels of ROS and disturbance of the antioxidant enzymes activities in the brain, which may further enhance lipid peroxidation and DNA damage. Furthermore, acetylcholinesterase activity was first stimulated and inhibited by exposure to DEHP, and the antioxidant and apoptosis related genes were mainly upregulated. Risk assessment indicated that the ecotoxicity of DEHP on the zebrafish showed an "enhancement-reduction" trend as the exposure time was prolonged. Overall, these results provided new insights and useful information to ecological risk assessment and environmental management of DEHP pollution.

Soil health hazards of di(2-ethylhexyl) phthalate: New perspectives on earthworms from different ecological niches DNA damage, gut microbial disruption and soil enzyme changes.

Di(2-ethylhexyl) phthalate (DEHP) is perceived an emerging threat to terrestrial ecosystem, however, clear and accurate studies to fully understander ecotoxicity and underlying mechanisms of DEHP on the soil fauna remain poorly understood. Therefore, this study conducted a microcosm experiment of two earthworm ecotypes to investigate the ecological hazards of DHEP from multiple perspectives. The results showed that DEHP significantly increased the 8-hydroxy-deoxyguanosine (8-OHdG) content both in Eisenia foetida (13.76-133.0%) and Metaphire guillelmi (11.01-49.12%), leading to intracellular DNA damage. Meanwhile, DEHP negatively affected the expression of functional genes (ATP-6, NADH1, COX), which may be detrimental to mitochondrial respiration and oxidative stress at the gene level. The two earthworm guts shared analogous dominant bacteria however, the incorporation of DEHP drastically suppressed the homogeneity and diversity of the gut microbes, which further disrupted the homeostasis of the gut microbial ecological network. The keystone species in the gut of E. foetida decreased under DEHP stress but increased in the gut of M. guillelmi. Moreover, DEHP presented detrimental effects on soil enzyme activity, which is mainly associated with pollutant levels and earthworm activity. Collectively, the findings expand the understanding of soil ecological health and reveal the underlying mechanisms of the potential exposure risk to DEHP.

Expanding the insight of ecological risk on the novel chiral pesticide mefentrifluconazole: Mechanism of enantioselective toxicity to earthworms (Eisenia fetida).

Continued application of new chiral fungicide mefentrifluconazole (MFZ) increases its risk to soil ecosystem. However, the toxicity of MFZ enantiomers to soil fauna and whether stereoselectivity exists remains poorly elucidated. Based on multilevel toxicity endpoints and transcriptomics, we investigated the negative effects of racemic, R-(-)-, and S-(+)-MFZ on Eisenia fetida. After exposure to S-(+) configuration at 4 mg/kg for 28 day, its reactive oxygen species levels were elevated by 15.4% compared to R-(-) configuration, inducing enantiospecific oxidative stress and transcriptional aberrations. The S-(+) isomer induced more severe cell membrane damage and apoptosis than the R-(-) isomer, and notably, the selectivity of apoptosis is probably dominated by the mitochondrial pathway. Mechanistically, differential mitochondrial stress lies in: S-(+) isomer specifically up-regulated mitochondrial cellular component compared to R-(-) isomer and identified more serious mitochondrial fission. Furthermore, S-(+) conformation down-regulated biological processes associated with ATP synthesis and metabolism, with specific inhibition of mitochondrial respiratory electron transport chain complex I and IV activity resulting in more severe electron flow disturbances. These ultimately mediated enantioselective ontogenetic process disorders, which were supported at phenotypic (weight loss), genetic, and protein (reverse modulate TCTP and Sox2 expression) levels. Our findings offer an important reference for elucidating the enantioselective toxicological mechanism of MFZ in soil fauna.

Mechanism of the adverse outcome of Chlorella vulgaris exposure to diethyl phthalate: Water environmental health reflected by primary producer toxicity.

As a ubiquitous contaminant in aquatic environments, diethyl phthalate (DEP) is a major threat to ecosystems because of its increasing utilization. However, the ecological responses to and toxicity mechanisms of DEP in aquatic organisms remain poorly understood. To address this environmental concern, we selected Chlorella vulgaris (C. vulgaris) as a model organism and investigated the toxicological effects of environmentally relevant DEP concentrations at the individual, physiological, biochemical, and molecular levels. Results showed that the incorporation of DEP significantly inhibited the growth of C. vulgaris, with inhibition rates ranging from 10.3 % to 83.47 %, and disrupted intracellular chloroplast structure at the individual level, while the decrease in photosynthetic pigments, with inhibition rates ranging from 8.95 % to 73.27 %, and the imbalance of redox homeostasis implied an adverse effect of DEP at the physio-biochemical level. Furthermore, DEP significantly reduced the metabolic activity of algal cells and negatively altered the cell membrane integrity and mitochondrial membrane potential. In addition, the apoptosis rate of algal cells presented a significant dose-effect relationship, which was mainly attributed to the fact that DEP pollutants regulated Ca2+ homeostasis and further increased the expression of Caspase-8, Caspase-9, and Caspase-3, which are associated with internal and external pathways. The gene transcriptional expression profile further revealed that DEP-mediated toxicity in C. vulgaris was mainly related to the destruction of the photosynthetic system, terpenoid backbone biosynthesis, and DNA replication. Overall, this study offers constructive understandings for a comprehensive assessment of the toxicity risks posed by DEP to C. vulgaris.

Photocatalytic degradation of butyl benzyl phthalate by S-scheme Bi/Bi2O2CO3/Bi2S3 under simulated sunlight irradiation.

As a kind of plasticizer, butyl benzyl phthalate (BBP) presents a serious hazard to the ecosystem. Therefore, there is a strong need for an effective technique to eliminate the risk of BBP. In this work, a new photocatalyst of Bi/Bi2O2CO3/Bi2S3 with an S-scheme heterojunction was synthesized using Bi(NO3)3 as the Bi source, Na2S as the S source, and DMF as the carbon source and reductant. Numerous techniques have been used to characterize Bi/Bi2O2CO3/Bi2S3, such as scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The improved photoactivity of Bi/Bi2O2CO3/Bi2S3 was evaluated by photoelectrochemical response, electrochemical impedance spectroscopy, photoluminescence, UV-Vis diffuse reflectance spectroscopy, and electrochemical Mott Schottky spectroscopy. The enhanced photocatalytic activity of this composite for BBP degradation under simulated sunlight irradiation could be attributed to the surface plasmon resonance effect of Bi metal and the heterojunction structure of Bi2O2CO3 and Bi2S3. The degradation rate of Bi/Bi2O2CO3/Bi2S3 was 85%, which was 4.52 and 1.52 times that of Bi2O2CO3 and Bi2S3, respectively. The prepared photocatalyst possessed good stability and reproducibility in eliminating BBP. The improved photocatalytic activity of Bi/Bi2O2CO3/Bi2S3 was demonstrated with the formation of an S-scheme heterojunction, and the degradation mechanism was discussed with a liquid chromatograph mass spectrometer.

Occurrence and health risk assessment of phthalates in a typical estuarine soil: A case study of the various functional areas of the Yellow River Delta.

In recent years, the extensive distribution of phthalates (PAEs) in soils has attracted increasing attention. In this study, the concentrations of six types of PAEs were measured in five dissimilar regions of the Yellow River Delta (YRD), and regional differences, pollution characteristics and health risks of PAEs pollution were investigated. The detection rate of PAEs was 100 %, and the concentration range of Σ6PAEs was 0.709-9.565 mg/kg, with an average of 3.258 ± 2.031 mg/kg. There were different spatial distribution differences of PAEs in soils of the YRD, with residential living, chemical industrial, and crop growing areas being the main areas of PAEs distribution. It was worth noting that di (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) are prominent contributors to PAEs in soils of the YRD. Correlation analyses showed that soils physicochemical properties such as SOM, TN and CEC were closely correlated to the transport and transformation of PAEs. Use by petrochemical industries, accumulation of plasticizers, additives (derived from cosmetics, food, pharmaceutical), fertilizers, pesticides, plastics, and atmospheric deposition are the principal sources of PAEs in the YRD. A health risk assessment showed that the health risk caused by non-dietary intake of PAEs was low and considered acceptable. PAEs pollution in the YRD soil is particularly noteworthy, especially for the prevention and control of DEHP and DBP pollution. This study provides basic data for an effective control of soil PAEs pollution in the YRD, which is conducive to the sustainable development of the region.

Multi-level biological effects of diverse alkyl chains phthalate esters on cotton seedlings (Gossypium hirsutum L.): Insights into individual, physiological-biochemical and molecular perspectives.

Phthalate esters (PAEs) are organic contaminants that pose environmental threat and safety risks to soil health and crop production. However, the ecological toxicity of different PAEs to cotton and the underlying mechanisms are not clear. This study investigated the ecotoxic effects and potential mechanisms of different alkyl-chain PAEs, including dioctyl phthalate (DOP), dibutyl phthalate (DBP), and diethyl phthalate (DEP) on cotton seedlings at multiple levels. The results showed that PAEs significantly hindered the growth and development of cotton. The chlorophyll content decreased by 1.87-31.66 %, accompanied by non-stomatal photosynthetic inhibition. The antioxidant system was activated by the three PAEs in cotton seedlings, while the osmotic potential was boosted intracellularly. Additionally, PAEs significantly interfered with functional gene expression and exhibited genotoxicity. Risk assessment results indicated that the ecotoxicity was DOP >DBP >DEP, with a "dose-response" relationship. The affinity between the three PAEs and catalase increased as the alkyl chain length increased, further supporting the toxicity sequence. Surprisingly, the bioconcentration factors of short-chain DEP were 8.07 ± 5.89 times and 1837.49 ± 826.83 times higher than those of long-chain DBP and DOP, respectively. These results support the ecological risk assessment of PAEs in cotton and provide new insights into determining the toxicity levels of different PAEs.

Cyantraniliprole seed treatment effectively controls wireworms (Pleonomus canaliculatus Faldermann) and white grubs (Anomala corpulenta Motschulsky) in maize fields.

Wireworms and white grubs are destructive underground pests in maize fields in China. Cyantraniliprole has good control effect on coleoptera pests. Here, we evaluated the toxicity of cyantraniliprole to the second instar larvae of Anomala corpulenta Motschulsky and third-instar of larvae of Pleonomus canaliculatus Faldermann and the effects of sublethal concentrations on the activity of antioxidant and detoxification enzymes. We also explored the efficacy of cyantraniliprole on underground pests under indoor and field conditions. The LC50 of cyantraniliprole for the third instar larvae of P. canaliculatus was 23.3712 mg/L, and that for the second instar larvae of A. corpulenta was 5.9715 mg/L. Cyantraniliprole can activate the activity of superoxide dismutase (SOD), peroxidase (POD), and glutathione S-transferase (GST) to different degrees at a sublethal dose. According to the pot experiment and the control efficacy test in the field, the indoor control effect of cyantraniliprole seed treatment on P. canaliculatus and white grubs was approximately 80%, and the maximum increase in yield achieved through cyantraniliprole application was approximately 15% in the field efficacy test. Cyantraniliprole has a strong control effect on wireworms and white grubs, so it can be used to treat seeds to control underground pests in maize fields.

Physiological and biochemical regulation of tobacco by oxathiapiprolin under Phytophthora nicotianae infection.

As a fungicide, oxathiapiprolin has excellent effects on diseases caused by oomycetes. Fungicides generally protect crops by inhibiting pathogens, but little research has addressed the effects of fungicides on crops. This study combined transcriptomic and metabolomic analyses to systematically analyze the physiological regulatory mechanisms of oxathiapiprolin on tobacco under Phytophthora nicotianae infection. The results showed that under P. nicotianae infection, tobacco's photosynthetic rate and antioxidant enzyme activity increased after the application of oxathiapiprolin. Omics results showed that the genes related to carbon metabolism, disease-resistant proteins, and amino acid synthesis were highly expressed, and the amino acid content increased in tobacco leaves. This study is the first comprehensive investigation of the physiological regulatory effects of oxathiapiprolin on tobacco in response to P. nicotianae infection. These findings provide a basis for the balance between regulating tobacco growth and development and enhancing disease resistance under the stimulation of oxathiapiprolin and provide new research and development opportunities for identifying new disease-resistance genes and the development of high-yielding disease-resistant crop varieties.

One-step synthesis of Bi2O2CO3/Bi2S3 S-scheme heterostructure with enhanced photoactivity towards dibutyl phthalate degradation under visible light.

Bi2O2CO3/Bi2S3 heterojunction was prepared by one-step hydrothermal method, where Bi(NO3)3 was employed as Bi source, Na2S was used as a sulfur source, and CO(NH2)2 was adopted as C source. The load of Bi2S3 was adjusted by changing the content of Na2S. The prepared Bi2O2CO3/Bi2S3 illustrated strong photocatalytic activity towards dibutyl phthalate (DBP) degradation. The degradation rate was 73.6% under the irradiation of visible light for 3 h, which were 3.5 and 1.87 times for Bi2O2CO3 and Bi2S3, respectively. In addition, the mechanism for the enhanced photoactivity was investigated. After combined with Bi2S3, the formed heterojunction structure inhibited the recombination of photogenerated electron-hole pair, improved the visible light adsorption, and accelerated the migration rate of the photogenerated electron. As a result, analysis of the radical formation and the energy band structure revealed that Bi2O2CO3/Bi2S3 was consistent with the S-scheme heterojunction model. The S-scheme heterojunction allowed the Bi2O2CO3/Bi2S3 to possess high photocatalytic activity. The prepared photocatalyst presented acceptable cycle application stability. This work not only develops a facile one-step synthesis technique for Bi2O2CO3/Bi2S3, and also provides a good platform for the degradation of DBP.

Evaluation of soil ecological health after exposure to environmentally relevant doses of Di (2-ethylhexyl) phthalate: Insights from toxicological studies of earthworms at different ecological niches.

As one of the most critical soil faunas in agroecosystems, earthworms are significant in preserving soil ecological health. Di (2-ethylhexyl) phthalate (DEHP) is a major plasticizer and widely used in plastic products like agricultural films. However, it has become ubiquitous contaminant in agricultural soil and poses a potential threat to soil health. Although the awareness of the impacts of DEHP on soil ecology is increasing, its adverse effects on soil invertebrates, especially earthworms, are still not well developed. In this study, the ecotoxicological effects and underlying mechanisms of environmentally relevant doses DEHP on earthworms of different ecological niches were investigated at the individual, cytological, and biochemical levels, respectively. Results showed that the acute toxicity of DEHP to M. guillelmi was higher than E. foetida. DEHP induced reactive oxygen species (ROS) levels and further caused oxidative damage (including cellular DNA and lipid peroxidation damage) in both species, speculating that they may exhibit similar oxidative stress mechanisms. Furthermore, two earthworms presented the alleviated toxicity when re-cultured in uncontaminated circumstances, yet, the accumulated ROS in bodies could not be completely scavenged. Risk assessment indicated that the detrimental impacts of DEHP were more significant in the M. guillelmi than in E. foetida in whole experiments prides, and the biomarkers additionally showed a species-specific trend. Besides, molecular docking revealed that DEHP could bind to the active center of superoxide dismutase/catalase (SOD/CAT) by hydrogen bonding or hydrophobic interactions. Overall, this study will provide a novel insight for accurate contaminant risk assessment, and also highlight that the comprehensive biological effects of different species should be emphasized in soil ecological health diagnostics and environmental toxicology assays, as otherwise it may lead to underestimation or misestimation of the soil health risk of contaminants.

Ecotoxicological and biochemical effects of di(2-ethylhexyl)phthalate on wheat (Jimai 22, Triticum aestivum L.).

Di(2-ethylhexyl)phthalate esters (DEHP) has attracted widespread attention due to its ecotoxicological effects on organisms. In this study, wheat seedlings were exposed to DEHP- contaminated soil with 4 concentration gradients (0, 1, 10, and 100 mg kg-1, respectively) for 30 days. The growth index, physiological index, oxidative damage system, and gene expression of wheat seedlings were comprehensively measured and analyzed. The results revealed that DEHP could reduce the germination rate of wheat. Only the 100 mg kg-1 treatment group significantly inhibited root length, but no effect on plant height. At the biochemical level, photosynthetic pigments of wheat seedlings were promoted first and then inhibited, while the soluble sugar content presented a trend of "inhibition - activation - inhibition". The antioxidant enzymes (SOD and POD) presented an approximate parabolic trend, while it was opposite for CAT. Whereas the corresponding antioxidant enzyme genes were up-regulated, and the Hsp70 heat-shock protein gene was down-regulated. Finally, integrated biological response index (IBR) analysis showed that the DEHP toxicity to wheat seedlings was dose dependent. Molecular docking indicated that DEHP could stably bind to GBSS and GST by intermolecular force. Overall, this study provided constructive insights for a comprehensive assessment of the toxicity risk of DEHP to wheat.

Extreme environmental doses of diisobutyl phthalate exposure induce oxidative stress and DNA damage in earthworms (Eisenia fetida): Evidence at the biochemical and molecular levels.

Diisobutyl phthalate (DIBP), as a plasticizer, is widely used and has caused many extreme soil contamination scenarios, posing potential risks to soil fauna. However, the toxic effects and mechanisms of DIBP on soil fauna remain unclear. In this study, earthworms (Eisenia fetida) were used as model animals to explore the subchronic toxicity of extreme DIBP soil exposure (300, 600, and 1200 mg/kg) for 28 days. The results showed that the level of reactive oxygen species (ROS) and the contents of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in E. fetida were significantly increased during continuous DIBP exposure. In addition, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were significantly inhibited while glutathione S-transferase (GST) activity was activated during continuous exposure. Integrated biological response (IBR) analysis showed that DIBP had positive dose-dependent toxicity and negative time-dependent toxicity to E. fetida, and SOD/CAT were selected as sensitive biomarkers. The molecular docking study found that DIBP could stably bind to SOD/CAT through hydrogen bonding, which further proved its sensitivity. This study provides primary data for ecological and environmental risk assessment of extreme dose DIBP soil pollution.

Occurrence, source, ecological risk, and mitigation of phthalates (PAEs) in agricultural soils and the environment: A review.

The widespread distribution of phthalates (PAEs) in agricultural soils is increasing drastically; however, the environmental occurrence and potential risk of PAEs in agricultural systems remain largely unreviewed. In this study, the occurrence, sources, ecotoxicity, exposure risks, and control measures of PAEs contaminants in agricultural soils are summarized, and it is concluded that PAEs have been widely detected and persist in the soil at concentrations ranging from a few µg/kg to tens of mg/kg, with spatial and vertical variations in China. Agrochemicals and atmospheric deposition have largely contributed to the elevated contamination status of PAEs in soils. In addition, PAEs cause multi-level hazards to soil organisms (survival, oxidative damage, genetic and molecular levels, etc.) and further disrupt the normal ecological functions of soil. The health hazards of PAEs to humans are mainly generated through dietary and non-dietary pathways, and children may be at a higher risk of exposure than adults. Improving the soil microenvironment and promoting biochemical reactions and metabolic processes of PAEs are the main mechanisms for mitigating contamination. Based on these reviews, this study provides a valuable framework for determining future study objectives to reveal environmental risks and reduce the resistance control of PAEs in agricultural soils.

Environmentally relevant concentrations of butyl benzyl phthalate triggered oxidative stress and apoptosis in adult zebrafish (Danio rerio) liver: Combined analysis at physiological and molecular levels.

Butyl benzyl phthalate (BBP), a typical phthalate plasticizer, is frequently detected in aquatic environments, but its possible effects on fish liver are unknown. In this study, adult zebrafish were exposed to 5-500 µg/L BBP and cultured for 28 days. The toxicity mechanism of environmentally relevant concentrations of BBP in the liver was explored using integrated biomarker response (IBR), molecular docking, and histopathological analysis, based on the tests of oxidative stress, apoptosis, and tissue damage, respectively. The results revealed that exposure to 500 µg/L BBP caused lipid peroxidation and DNA damage and induced inflammatory responses in the liver and intestinal tissues. The accumulation of reactive oxygen species (ROS) is the primary manifestation of BBP toxicity and is accompanied by changes in the activities of antioxidant and detoxification enzymes. Notably, the pro-apoptotic genes (p53 and caspase-3) were still significantly upregulated in the 50 µg/L and 500 µg/L treatment groups on day 28. Moreover, BBP interfered with apoptosis by forming a stable complex with apoptosis proteins (P53 and Caspase-3). Our findings are helpful for understanding the toxicity mechanisms of BBP, which could further promote the assessment of the potential environmental risks of BBP.

Direct toxicity of the herbicide florasulam against Chlorella vulgaris: An integrated physiological and metabolomic analysis.

Herbicides are the agents of choice for use in weed control; however, they can enter the aquatic environment, with potentially serious consequences for non-target organisms. Despite the possible deleterious effects, little information is available regarding the ecotoxicity of the herbicide florasulam toward aquatic organisms. Accordingly, in this study, we investigated the toxic effect of florasulam on the freshwater microalga Chlorella vulgaris and sought to identify the underlying mechanisms. For this, we employed a growth inhibition toxicity test, and then assessed the changes in physiological and metabolomic parameters, including photosynthetic pigment content, antioxidant system, intracellular structure and complexity, and metabolite levels. The results showed that treatment with florasulam for 96 h at the concentration of 2 mg/L, 2.84 mg/L, and 6 mg/L in medium significantly inhibited algal growth and photosynthetic pigment content. Moreover, the levels of reactive oxygen species were also increased, resulting in oxidative damage and the upregulation of the activities of several antioxidant enzymes. Transmission electron microscopic and flow cytometric analysis further demonstrated that exposure to florasulam (6 mg/L) for 96 h disrupted the cell structure of C. vulgaris, characterized by the loss of cell membrane integrity and alterations in cell morphology. Changes in amino acid metabolism, carbohydrate metabolism, and the antioxidant system were also observed and contributed to the suppressive effect of florasulam on the growth of this microalga. Our findings regarding the potential risks of florasulam in aquatic ecosystems provide a reference for the safe application of this herbicide in the environment.

Toxicity of dibutyl phthalate to pakchoi (Brassica campestris L.): Evaluation through different levels of biological organization.

Dibutyl phthalate (DBP) is a typical persistent organic pollutant with a high load in the agricultural soils of vegetable crops. Currently, studies on the toxicity of DBP in vegetable crops are limited. Therefore, in this study, pakchoi (Brassica campestris L.), a typical vegetable crop, was used to evaluate the toxic effects of DBP. Pakchoi was exposed to DBP for 24 d at three doses (2, 20, and 200 mg/kg), and the phenotypic, biochemical, and molecular indicators were determined. The results revealed that DBP could reduce the emergence of pakchoi and inhibit plant height, root length, fresh weight, and leaf area. At the biochemical level, DBP exposure could reduce the content of three typical photosynthetic pigments (chlorophyll a and b and carotenoids). The effects of DBP exposure on the quality of pakchoi were primarily through reduced soluble sugar and increased proline contents. In addition, O2·- and H2O2 levels increased after DBP stress, and the corresponding antioxidant enzymes (SOD, POD, and CAT) were activated to resist oxidative damage. The dose- and time-dependent toxicities of DBP to pakchoi were demonstrated using an integrated biological response index. Finally, the molecular-level results on Day 24 showed that the three antioxidant enzyme genes (sod, pod, and cat) were significantly downregulated, and the antioxidant enzyme genes were more sensitive biomarkers than the enzyme activities. However, the expression level of enzyme genes was opposite to that of enzyme activity (SOD and POD); thus, DBP might directly interact with these enzymes. Molecular docking showed that DBP could stably bind near the SOD/POD active center through intermolecular interaction forces. This study provides essential information on the risk of DBP toxicity to vegetable crops.

Toxic effects of fludioxonil on the growth, photosynthetic activity, oxidative stress, cell morphology, apoptosis, and metabolism of Chlorella vulgaris.

Fludioxonil is widely used in the control of crop diseases because of its broad spectrum and high activity, but its presence is now common in waterways proximate to treated areas. This study examined the toxic effects and mechanisms of fludioxonil on the microalgal taxa Chlorella vulgaris. The results showed that fludioxonil limited the growth of C. vulgaris and the median inhibitory concentration at 96 h was 1.87 mg/L. Concentrations of 0.75 and 3 mg/L fludioxonil reduced the content of photosynthetic pigments in algal cells to different degrees. Fludioxonil induced oxidative damage by altering C. vulgaris antioxidant enzyme activities and increasing reactive oxygen species levels. Fludioxonil at 0.75 mg/L significantly increased the activity of antioxidant enzymes. The highest level of activity was 1.60 times that of the control group. Both fludioxonil treatment groups significantly increased ROS levels, with the highest increase being 1.90 times that of the control group. Transmission electron microscope showed that treatment with 3 mg/L fludioxonil for 96 h disrupted cell integrity and changed cell morphology, and flow cytometer analysis showed that fludioxonil induced apoptosis. Changes in endogenous substances indicated that fludioxonil negatively affects C. vulgaris via altered energy metabolism, biosynthesis of amino acids, and unsaturated fatty acids. This study elucidates the effects of fludioxonil on microalgae and the biological mechanisms of its toxicity, providing insights into the importance of the proper management of this fungicide.

Effects of thifluzamide on soil fungal microbial ecology.

Thifluzamide, a succinate dehydrogenase inhibitor fungicide, has been used extensively for many diseases control and has the risk of accumulation in soil ecology. In order to study the ecotoxicity of thifluzamide to soil fungal communities, typical corn field soils in north (Tai'an) and south (Guoyang) China were treated with thifluzamide (0, 0.1, 1.0 and 10.0 mg/kg) and incubated for 60 days. Thifluzamide exposure promoted soil basal respiration, and significantly reduced the number of soil culturable fungi and the abundance of soil fungi (RT-qPCR) in middle and late treatment period (15, 30, 60 days). Illumina Mi-Seq sequencing revealed that thifluzamide could reduce fungal alpha diversity (Sobs, Shannon, Simpson indexes) and change fungal community structure. FUN Guild analysis showed that the relative abundance of Undefined Saprotroph increased after the thifluzamide treatment, whereas that of Plant Pathogen decreased, and we concluded that exposure to thifluzamide could change the function of soil fungi. This study evaluated the soil ecological risk caused by thifluzamide's release into soil, providing a basis for its rational application.

Transcriptomics and enzymology combined five gene expressions to reveal the responses of earthworms (Eisenia fetida) to the long-term exposure of cyantraniliprole in soil.

Cyantraniliprole is a novel diamide insecticide that acts upon the ryanodine receptor (RyR) and has broad application prospects. Accordingly, it is very important to evaluate the toxicity of cyantraniliprole to earthworms (Eisenia fetida) because of their vital role in maintaining a healthy soil ecosystem. In this study, an experiment was set up, using four concentrations (0.1, 1, 5, and 10 mg/kg) and solvent control group (0 mg/kg), to investigate the ecotoxicity of cyantraniliprole to earthworms. Our results showed that, after 28 days of exposure to cyantraniliprole, both cocoon production and the number of juvenile earthworms had decreased significantly at concentrations of either 5 or 10 mg/kg. On day 14, we measured the activities of digestive enzymes and ion pumps in the intestinal tissues of earthworms. These results revealed that cyantraniliprole exposure caused intestinal damage in earthworm, specifically changes to its intestinal enzyme activity and calcium ion content. Cyantraniliprole could lead to proteins' carbonylation under the high-dose treatments (i.e., 5 mg/kg, 10 mg/kg). At the same time, we also found that cyantraniliprole can cause the abnormal expression of key functional genes (including HSP70, CAT, RYR, ANN, and CAM genes). Moreover, the transcriptomics data showed that exposure to cyantraniliprole would affect the synthesis of carbohydrates, proteins and lipids, as well as their absorption and transformation, while cyantraniliprole would also affect signal transduction. In general, high-dose exposure to cyantraniliprole causes reproductive toxicity, genotoxicity, and intestinal damage to earthworms.