Gene cloning and expression of heat shock protein gene from Aleuroglyphus ovatus and its response to temperature stress

摘要

Aleuroglyphus ovatus is a major mite pest of stored products worldwide, which can seriously impact human health and economic outcomes. Temperature has a great influence on the population dynamics of A. ovatus. Synthesis of heat shock protein (Hsp) is one of the protective mechanisms that enable mites to cope with heat stress. In this study, two full-length cDNA sequences of AoHsp70-1 and AoHsp70-2 from A. ovatus were cloned and expressed. AoHsp70-1 and AoHsp70-2 gene sequences were 2307 and 2623 base pairs (bp) in length, respectively. The open reading frames of AoHsp70-1 and AoHsp70-2 were 1974 and 1923 bp, which encoded 657 and 640 amino acid residues, respectively. The deduced amino acid sequences of AoHsp70-1 and AoHsp70-2 demonstrated their high homology with other mites and insects. The mRNA expression levels of AoHsp70 at different developmental stages and under temperature stress were evaluated. The obtained results showed that the expression levels of Hsp70 differ between each developmental stage (i.e. eggs, larvae, nymphs, and female adults) of A. ovatus. Different responses of AoHsp70-1 and AoHsp70-2 to temperature stress suggested that the deduced amino acids of AoHsp70-1 and AoHsp70-2 were constitutive and inducible proteins, respectively. The inducible AoHsp70-2 may play a role in promoting temperature resistance in A. ovatus. The increased expression levels of AoHsp70-2 under heat stress indicated that A. ovatus was more sensitive to high temperature. The findings from this study may provide insight into the mechanisms underlying heat stress resistance in A. ovatus.