Copper (Cu) is a toxic metal that accumulates in soil due to agricultural and industrial activities, potentially impacting plant growth and productivity. Our study examined the phytotoxic effects of Cu on Vigna radiata L. by exposing plants to a series of Cu concentrations (1, 4 and 7 mM) under controlled conditions. Growth parameters, photosynthetic performance, biochemical traits, and oxidative stress indicators were analyzed in 21-day-old Cu-treated plants and compared with control plants. The results demonstrated a concentration-dependent decline in shoot and root biomass, relative water content (RWC), pigment content, photosynthetic efficiency, carbohydrates, and lipid content. Conversely, oxidative stress markers such as malondialdehyde (MDA), electrolyte leakage, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity and proline accumulation increased significantly with increasing Cu concentrations, indicating cellular damage. Notably, protein levels increased with increased Cu concentrations, which may contribute to their tolerance to metal stress, however, it was insufficient to mitigate stress. Further research is needed to validate these findings and explore the mechanisms underlying copper stress tolerance.

Soil worms are among the most abundant and functionally diverse soil animals. However, they have been largely overlooked in studies on microplastic (MP) toxicity. MPs and plant secondary metabolites (PSMs) are ubiquitous in soil due to plant litter decomposition and heavy MP contamination, inevitably interacting and exerting combined toxicity on soil organisms. However, little research has been conducted on their joint effects. This study investigates the individual and combined toxic effects of polyethylene (PE) MPs and three PSMs (glycyrrhizic acid, tannic acid, and matrine) on the model organism Caenorhabditis elegans. Physiological and biochemical responses were assessed using fluorescence microscopy, image analysis, and statistical methods. After 42 h of exposure to PE MPs and/or PSMs, worm growth and development were negatively impacted. Under experimental conditions, matrine and PE MPs synergistically inhibited worm growth, exacerbated neurological damage, and induced oxidative stress. In contrast, glycyrrhizic acid and tannic acid alleviated PE MP-induced growth inhibition, mitigated oxidative stress, and demonstrated antioxidant properties that counteracted oxidative damage. This study offers new insights into the combined effects of MPs and PSMs in soil ecosystems, contributing to ecological risk assessments and pollution management strategies.

Soil is an important sink for microplastics (MPs) and pesticides. MPs can act as carriers for pesticides, thus induce direct and indirect effects on soil organisms. Fluindapyr (FIP), a novel succinate dehydrogenase inhibitors fungicides (SDHIs), may pose a serious threat to earthworms. However, few studies have evaluated the effects of joint exposure to MPs and FIP. Here, earthworms (Eisenia fetida) were jointly exposed to PMMA (polymethylmethacrylate) and PS (polystyrene) MPs of different sizes (0.1, 1 and 10 mu m) along with FIP for 28-day to investigate the toxic effects of single and joint exposure of FIP and MPs on earthworms. The results showed that joint exposure to 0.1 and 1 mu m MP promoted the accumulation of FIP in earthworms at the beginning of the experiment compared to the sole group, but the elimination of FIP from earthworms accelerated after 14 d. In addition, the joint exposure caused more serious damages to the epidermis and intestine of earthworms and increased the severity of oxidative stress. The effects of joint exposure to FIP and MPs depended on the size of the MPs, and the strongest effects were observed in the treatment with the smallest size. The 16S rRNA sequencing results showed that the joint exposure to MPs and FIP didn't cause gut microbiota dysbiosis. However, the sole 0.1 mu m PS significantly altered the community diversity and richness of earthworm gut bacteria, and the relative abundance of Proteobacteria, Actinobacteria and Firmicutes was significantly changed. The obtained results inferred that MPs could influence environmental and toxicological behaviors of FIP and may provide data support for the risk assessments of MPs and FIP on soil ecosystems.

Inorganic arsenic species exist in the environment as a result of both natural sources, such as volcanic and geothermal activities, and geological formations, as well as anthropogenic activities, including smelting, exploration of fossil fuels, coal burning, mining, and the use of pesticides. These species deposit in water, rocks, soil, sediments, and the atmosphere. Arsenic-contaminated drinking water is a global public health issue because of its natural prevalence and toxicity. Therefore, chronic exposure to arsenic can have deleterious effect on humans, including cancer and other diseases. This work describes the mechanisms of environmental exposure to arsenic, molecular regulatory factors involved in its metabolism, genetic polymorphisms affecting individual susceptibility and the toxic effects of arsenic on human health (oxidative stress, DNA damage and cancer). We conclude that the role of single nucleotide variants affecting urinary excretion of arsenic metabolites are highly relevant and can be used as biomarkers of the intracellular retention rates of arsenic, showing new avenues of research in this field.

Nanoplastics (NPs) are currently everywhere and environmental pollution by NPs is a pressing global problem. Nevertheless, until now, few studies have concentrated on the mechanisms and pathways of cytotoxic effects and immune dysfunction of NPs on soil organisms employing a multidimensional strategy. Hence, earthworm immune cells and immunity protein lysozyme (LZM) were selected as specific receptors to uncover the underlying mechanisms of cytotoxicity, genotoxicity, and immunotoxicity resulting from exposure to polystyrene nanoplastics (PS-NPs), and the binding mechanisms of PS-NPs-LZM interaction. Results on cells indicated that when earthworm immune cells were exposed to high-dose PS-NPs, it caused a notable rise in the release of reactive oxygen species (ROS), resulting in oxidative stress. PS-NPs exposure significantly decreased the cell viability of earthworm immune cells, inducing cytotoxicity through ROS-mediated oxidative stress pathway, and oxidative injury effects, including reduced antioxidant defenses, lipid peroxidation, DNA damage, and protein oxidation. Moreover, PS-NPs stress inhibited the intracellular LZM activity in immune cells, resulting in impaired immune function and immunotoxicity by activating the oxidative stress pathway mediated by ROS. The results from molecular studies revealed that PS-NPs binding destroyed the LZM structure and conformation, including

There is a knowledge gap in the interaction between the effects of herbicide thiencarbazone-methyl center dot isoxaflutole on soil microflora and environmental parameters, which leads to a lack of measures in mitigating damage to bacterial communities from the herbicide use. The impacts of thiencarbazone-methyl center dot isoxaflutole and soil pa-rameters on the diversity, structure and functions of soil bacterial communities were clarified, and the effects and potential mitigation mechanisms of nitrapyrin and modified attapulgite with bacterial function intervention on bacterial communities were explored through incubation and field experiments. The results showed that as thiencarbazone-methyl center dot isoxaflutole application increased, the stress on soil bacterial community structure and diversity also increased. The relative abundance of bacteria including Aridibacter and GP7 and functional an-notations including nitrate_reduction were significantly negatively correlated with thiencarbazone-methyl-center dot isoxaflutole residues in soils. The remarkable toxic effects on the Adhaeribacter bacteria were detected at the recommended dose of thiencarbazone-methyl center dot isoxaflutole application. The residue of isoxaflutole (one of the effective ingredients of thiencarbazone-methyl center dot isoxaflutole) directly and more strongly affected the diversity of soil bacterial communities than thiencarbazone-methyl. Increasing soil pH was recognised as an important factor in improving the diversity and structure of soil microflora based on the results of the Mantel test and canonical correspondence analysis. Supplemental use of nitrapyrin or modified attapulgite was found to increase soil pH, and further improve the expression of manganese oxidation function annotation. This contributed to the increased bacterial diversity (Shannon index). Therefore, the disturbance of soil microflora caused by thien-carbazone-methyl center dot isoxaflutole application can be mitigated by the use of nitrapyrin and modified attapulgite through raising soil pH.