Characterization, and Functional Analysis of Hsp70 and Hsp90 Gene Families in Walker (Lepidoptera: Pyralidae).

Walker (Lepidoptera: Pyralidae) is a destructive mulberry pest, causing great damage to mulberry in China. Heat shock proteins (Hsps) are involved in various signal pathways and regulate lots of physiological processes in insects. The function of Hsps in , however, has still received less attention. Here, we identified five Hsp genes from transcriptome dataset including two Hsp70 family genes ( and ) and three Hsp90 family genes (, , and ). Quantitative Real-time PCR validation revealed that all Hsps of have significant expression in pupal and diapause stage, at which the larvae arrest the development. Expressions of and were increased significantly after thermal treatment at 40°C, and this upregulation depended on heat treatment duration. Furthermore, silencing by RNA interference led to a significant increase in mortality of larvae under the heat stress compared to the control group. After starvation stress, the expression levels of and were significantly increased. At last, after being parasitized by the parasitoid wasp , Hsp70 and Hsp90 genes of were decreased significantly in the early stage of parasitization and this moderation was affected by time post-parasitization. This study highlights the function of Hsps in response to environmental stress and provides a perspective for the control of this pest.