Roles of the protein disulphide isomerases AccPDIA1 and AccPDIA3 in response to oxidant stress in Apis cerana cerana

Protein disulphide isomerase (PDI) plays an important role in a variety of physiological processes through its oxidoreductase activity and molecular chaperone activity. In this study, we cloned two PDI family members, AccPDIA1 and AccPDIA3, from Apis cerana cerana. AccPDIA1 and AccPDIA3 had typical sequence features of PDI family members and were constitutively expressed in A. cerana cerana. The expression levels of AccPDIA1 and AccPDIA3 were generally upregulated after treatment with a variety of environmental stress factors. Inhibition assays showed that E. coli expressing recombinant AccPDIA1 and AccPDIA3 proteins was more resistant to oxidative stress than control E. coli. In addition, silencing AccPDIA1 or AccPDIA3 in A. cerana cerana resulted in significant changes in the expression levels of several antioxidant-related genes as well as the enzymatic activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) and reduced the survival rate of A. cerana cerana under oxidative stress caused by high temperature. In conclusion, our results suggest that AccPDIA1 and AccPDIA3 may play important roles in the antioxidant activities of A. cerana cerana.