Transcriptome Changes Reveal the Toxic Mechanism of Cadmium and Lead Combined Exposure on Silk Production and Web-Weaving Behavior of Spider A. ventricosus

Impact of triclocarban exposure on development and gene expression in the wolf spider, Pardosa pseudoannulata (Araneae: Lycosidae)

Triclocarban (TCC), an emerging organic contaminant, poses a potential threat to water resources and ecosystems. The wolf spider Pardosa pseudoannulata (Araneae: Lycosidae) is a dominant predator typically inhabiting rice fields or wet habitats near water sources. However, little is known about the effects of TCC on the wolf spiders. In the present study, using environmentally relevant concentrations, we systematically investigated the toxicity of TCC on the early life stages of P. pseudoannulata at both physiological and gene expression levels. Our results indicated that TCC exposure did not significantly affect the survival and development of spiderlings. Transcriptome analysis revealed that TCC stress significantly impacted drug metabolism, cell cycle and signal transduction pathways in spiderlings. Subsequently, qRT-PCR was used to verify the expression levels of genes associated with drug metabolism and cell process, and the results were consistent with the transcriptome. These findings enhance our understanding of the toxic mechanism and ecological risk of TCC on arthropods.

LmGSTF3 Overexpression Enhances Cadmium Tolerance in Lemna minor

Glutathione S-transferase (GST) has been established to play an important role in regulating the responses of plants to stress, although its function and mechanisms of action in the cadmium (Cd)-tolerant Lemna minor remain unclear. In this study, we sought to identify a Cd-responsive GST gene from Lemna minor for functional analysis and mechanistic characterization. We accordingly identified a member of the GST gene family, LmGSTF3, which plays a positive role in adaptation of Lemna minor to Cd. Having successfully obtained overexpressing (OE) strains via genetic transformation, we established that these strains were characterized by elevated Cd tolerance compared with the wild-type strain, as evidenced by significant increases in growth rate, chlorophyll content, antioxidant enzyme activities, and Cd removal rate. At the transcriptome level, the OE strains were found to have a stronger regulatory ability in response to Cd, particularly with respect to photoprotection, antioxidant defense, and glycolytic metabolism, which may be key factors contributing to the Cd tolerance of Lemna minor. Our findings provide a basis for further elucidating the biochemical and molecular mechanisms underlying the Cd tolerance conferred by GST genes in Lemna minor and will potentially contribute to the utilization of Lemna minor in remediating aquatic pollution.

Investigating the Influence of Anthropogenic Activities on Behavioral Changes of an Orb Web Spider (Neoscona vigilans)

Orb web spiders are common and highly diversified animals found in almost all habitats. They have remarkable plasticity against biotic and abiotic factors, making them excellent indicators of environmental health. The web creation behavior of spiders is influenced by disturbances in the environment. The aim of this research was to observe the alteration in the web-building behavior of Neoscona vigilans caused by human activities, specifically traffic disturbances. Spider webs were located and photographed at nighttime along the roadside, and their web characteristics were calculated. Spiders were captured from webs for their body measurements. Spider fourth leg length, carapace width, and body length had a significant association with web size and diameter, CTL, capture area, and mesh size. The quantity of trapped prey, the height of the plant, and the foliage radius increased with the distance from the road. Conversely, anchor points and web elevation from the ground dropped. The highest and lowest proportions of anomalies (modifications/defects) were recorded as holes (52.7%) in 105 webs (100%) and supernumerary (0.7%) in 55 webs (52.4%), respectively. Road disturbance had a negative influence on the spider's behavior as the webs formed in close proximity to the road had a higher frequency of anomalies, with a gradual decrease distantly. We can gain further insight into how different environmental changes, disruptions, and pollutants lead to this imperfection in the otherwise flawless perfect structure of spider webs.

Exploring ecological effects of arsenic and cadmium combined exposure on cropland soil: from multilevel organisms to soil functioning by multi-omics coupled with high-throughput quantitative PCR

Arsenic (As) and cadmium (Cd) pose potential ecological threats to cropland soils; however, few studies have investigated their combined effects on multilevel organisms and soil functioning. Here, we used collembolans and soil microbiota as test organisms to examine their responses to soil As and Cd co-contamination at the gene, individual, and community levels, respectively, and further uncovered ecological relationships between pollutants, multilevel organisms, and soil functioning. At the gene level, collembolan transcriptome revealed that elevated As concentrations stimulated As-detoxifying genes AS3MT and GST, whereas the concurrent Cd restrained GST gene expression. At the individual level, collembolan reproduction was sensitive to pollutants while collembolan survival wasn't. At the community level, significant but inconsistent correlations were observed between the biodiversity of different soil keystone microbial clusters and soil As levels. Moreover, soil functioning related to nutrient (e.g., carbon, nitrogen, phosphorus, and sulfur) cycles was inhibited under As and Cd co-exposure only through the mediation of plant pathogens. Overall, these findings suggested multilevel bioindicators (i.e., AS3MT gene expression in collembolans, collembolan reproduction, and biodiversity of soil keystone microbial clusters) in cropland soils co-contaminated with As and Cd, thus improving the understanding of the ecotoxicological impact of heavy metal co-contamination on soil ecosystems.