Characterization of cadmium-responsive transcription factors in wolf spider Pardosa pseudoannulata.

Transcription factors (TFs) act on the regulation of gene expression, which is prevalent in all organisms, and their characterization may provide important clues for understanding the regulatory mechanism of gene expression. In this research, inhibited growth (delayed developmental time and decreased body weight) and increased activities of antioxidant enzymes (peroxidase, superoxide dismutase, and catalase) were recorded in Pardosa pseudoannulata in response to cadmium burden. Expression profiles of TFs were analyzed based on the transcriptome profiling of P. pseudoannulata, and 1711 TFs genes were differentially expressed with 995 up-regulated and 716 down-regulated. Most of the differentially expressed TFs belonged to zf-C2H2, ZBTB, Homeobox, and bHLH families. Interestingly, hub genes smads, TCF7L2, EGR1, and GATA5 were identified to be the candidate Cd-responsive TFs related to growth of spider. The expression level of Sod2 (superoxide dismutase) was regulated by the up-regulated TF foxo3, implying its important role in the antioxidant defense of spider. Moreover, sequence analysis demonstrated that smads and foxo3 were conserved among spiders and insects. This study revealed for the first time the role of TFs in molecular response of P. pseudoannulata to Cd stress, providing the basis for the protection of tarantula under Cd stress.