Integrated transcriptome and proteome unveiled distinct toxicological effects of long-term cadmium pollution on the silk glands of Pardosa pseudoannulata

Cadmium (Cd) induces severe soil pollution worldwide and exerts adverse effects on paddy field arthropods. Spiders grant a novel perspective to assess the Cd-induced toxicity, yet the impacts of long-term Cd stress on spider silk glands and its underlying mechanism remain elusive. The study showed that Cd stress enervated the antioxidant system in the spider Pardosa pseudoannulata, manifested as the decreases of glutathione peroxidase and peroxidase, and the increase of malonaldehyde (p < 0.05). In addition, a total of 1459 differentially expressed genes (DEGs) and 404 differentially expressed proteins (DEPs) were obtained from the silk glands' transcriptome and proteome. DEGs and DEPs encoding spidroin (e.g., tubuliform spidroin and ampullate spidroin) and amino acids metabolism (e.g., alanine, proline, and gly-cine) were distinctively down-regulated. Further enrichment analysis verified that Cd stress could inhibit amino acid metabolism via the down-regulation of several key enzymes, including glutathione synthase, methylthioadenosine phosphorylase, S-adenosylmethionine synthetase, etc. In addition, the hedgehog signaling pathway regulating cellular growth and development was down-regulated under Cd stress. A protein-protein interaction network showed that long-term Cd stress could inhibit some key biological processes in the silk glands, including peptide biosynthetic pro-cess and cytoskeleton part. Collectively, this comprehensive study established an effective animal detection model for evaluating Cd-induced toxicity, presented key biomarkers for further validation, and provided novel insights to inves-tigate the molecular mechanisms of spiders to Cd pollution.

Automated summary

This study investigated the effects of long-term cadmium stress on spider silk glands and revealed the inhibition of key biological processes and amino acid metabolism. The study also established an effective animal detection model for assessing cadmium-induced toxicity and provided insights into the molecular mechanisms of spiders to cadmium pollution.