Transcriptome analysis of hsp18.3 functions and regulatory systems using RNA-sequencing in the red flour beetle, Tribolium castaneum

Abstract

The red flour beetle, Tribolium castaneum, is a major agriculture pest of stored grain, cereal products and peanuts for human consumption. It is reported that heat shock protein 18.3 of T. castaneum (Tchsp18.3) plays a significant role in stress resistance, development and reproduction. However, the regulatory systems of Tchsp18.3 remain unknown. Therefore, we compared the global transcriptome profiles of RNA interference (RNAi)-treated larvae (ds-Tchsp18.3) and control larvae of T. castaneum using RNA sequencing. Overall, we obtained 14 154 435 sequence reads aligned with 13 299 genes. Additionally, 569 differentially expressed genes (DEGs) were identified from the ds-Tchsp18.3 and control groups, of which 246 DEGs were annotated in the 47 Gene Ontology (GO) functional groups and 282 DEGs were assigned to 147 Kyoto Encyclopedia of Genes and Genomes (KEGG) biological signaling pathways. The DEGs encoding viperin, dorsal, Hdd11, PGRP2, defensin1 and defensin2 were simultaneously related to immunity and stress responses, which suggests that cross-talk might exist between the immunity and stress responses of T. castaneum. The knockdown of Tchsp18.3 gene expression suppressed the antioxidant activity process, which most likely modulated the effects of Tchsp18.3 on development and reproduction. Furthermore, the DEGs, including Blimp-1, Gld, Drm, Kinesin-14, Pthr2, Delta(11)-like and EGF-like domain protein 2, were also associated with the development and reproduction of ds-Tchsp18.3 insects. Additionally, knockdown of Tchsp18.3 amplified the serine protease (SP) signaling pathway to further regulate stress responses and innate immunity as well as development and reproduction of the red flour beetles. These results provide valuable insight into the molecular regulatory mechanism of Tchsp18.3 involved in insect physiology and further facilitate the research of suitable and sustainable management for pest control.