Combined effects of cadmium and antibiotics on the immune defense system of the wolf spider Pardosa pseudoannulata.

This study investigated the compound stresses of cadmium (Cd) and antibiotics on the immune defense system of wolf spiders, Pardosa pseudoannulata, which is a vital predator for pest control in the paddy ecosystem. Overall, the synergistic effect of Cd and antibiotics on the inhibition of immune response was identified in spiderlings, which manifested by decreased resistance to a pathogen, reduced concentration of immune effectors, and altered concentrations of antioxidants. Similarly, changes in the relative abundances of several antimicrobial peptides, such as lycosins, lycotoxins, and pardosins, were consistent with the change of immune effectors. Specific responsive genes of compound stresses suggested a broader disturbance in the immune system, like the antioxidase system, phenoloxidase, and lysosome, as well as changes in the developmental events like the biosynthesis of molting and juvenile hormones in spiderlings, which were acknowledged as potential contributors to the combined exposure toxicity. Another group of genes involved in ribosome, energy metabolism, and phagosome can act as co-damage markers in response to alone or combined exposures of Cd and antibiotics. These results expanded the insights into the ecotoxicology assessment of combined pollutants in the paddy field.