Cadmium exposure improved the susceptibility of wolf spider Pardosa pseudoannulata to pathogen

The farmland soil polluted by heavy metals like cadmium (Cd) was widespread around the world. Cd pollution may pose significant challenges to paddy arthropods by compromising their ability to resist infections from parasites and pathogens. This study investigated the impact of Cd exposure on the resistance of the Pardosa pseudoannulata against the pathogenic bacterium Staphylococcus aureus. Ecotoxicology assay suggested that Cd exposure significantly reduced the spider's pathogen resistance, as evidenced by increased cumulative mortality rates and suppressed activities of key immune effectors or ATP levels. The decreased abundance of antibacterial peptides such as lycotoxins and lycosins was also identified. Multi-omics, RT-qPCR, and western blot analyses revealed a set of genes that play roles in the Cd burden response, of which Toll pathway and ribosomal protein genes may be potential contributors to the disturbed immune defense system. These findings expanded the toxicity mechanistic investigation of heavy metals on the fitness parameters of paddy predators.