Combined effects of spinetoram and Microcystis aeruginosa on Daphnia pulex offspring: Maternal effects and multigenerational implications

Cross-Generational Exposure to Low-Density Polyethylene Microplastics Induced Hyperactive Responses in Eisenia fetida Offsprings

The extensive application of plastic products in daily human life has led to the accumulation of microplastics (MPs) in agricultural soil. However, little is known about the cross-generational toxicity of MPs on terrestrial invertebrates. In this study, two-generational Eisenia fetida was exposed to low-density polyethylene (LDPE, 0-5%, w/w) for 98 days to reveal the cross-generational toxicity and the underlying mechanisms. Results showed that LDPE-MPs not only perpetrated deleterious effects on the development, hatchability, and fecundity of the F0 generation but also stimulated the antioxidant defense activity, inhibited lipid peroxidation, and disordered neurotransmission in F1 generation individuals. The susceptibility of the epidermal-intestinal barrier to LDPE-MPs was dose-dependent. According to the transcriptomic analysis, the cross-generational earthworms confirmed significant perturbances in the cell cycle, neural activity-related pathways, and amino acid metabolism pathways (p < 0.05). Nevertheless, the metabolomic profile of F1 generation individuals exhibited significant hyperactive responses in glutathione metabolism and alanine, aspartate, and glutamate metabolism (p < 0.05). This study provides a comprehensive knowledge of LDPE-MPs toxicity on cross-generational earthworms and highlights the hyperactive responses in the antioxidant defense performance of the offsprings. Our findings also underscore the necessity for long-term investigations in assessing the adverse impacts of emerging pollutants.

Concentration-dependent effects of spinetoram on nontarget freshwater microalgae: A comparative study on Chlorella vulgaris and Microcystis aeruginosa

The rising global demand for agricultural products is leading to the widespread application of pesticides, such as spinetoram, resulting in environmental pollution and ecotoxicity to nontarget organisms in aquatic ecosystems. This research focused on assessing the toxicity of spinetoram at various concentrations (0, 0.01, 0.1, 0.5, 1.0, and 3.0 mg L-1) on two common freshwater microalgae, Chlorella vulgaris and Microcystis aeruginosa, to shed light on the ecotoxicological effects of insecticides. Our findings demonstrate that M. aeruginosa is more sensitive to spinetoram than is C. vulgaris, with a concentration-dependent reduction in the growth rate observed for M. aeruginosa, whereas only the highest concentration of spinetoram adversely affected C. vulgaris. At a concentration of 0.01 mg L-1, the growth rate of M. aeruginosa unexpectedly increased beginning on day 7, indicating a potential hormetic effect. Although initial exposure to spinetoram improved the photosynthetic efficiency of both microalgae strains at all concentrations, detrimental effects became apparent at higher concentrations and with prolonged exposure. The photosynthetic efficiency of C. vulgaris recovered, in contrast to that of M. aeruginosa, which exhibited limited recovery. Spinetoram more significantly inhibited the effective quantum yield of PSII (EQY) in M. aeruginosa than in C. vulgaris. Although spinetoram is not designed to target phytoplankton, its toxicity can disrupt primary productivity and modify phytoplankton-consumer interactions via bottom-up control mechanisms. This study enhances our understanding of spinetoram's ecotoxicity and potential effects on aquatic ecosystems.