Transcriptome Analysis of Propylaea quatuordecimpunctata L. (Coleoptera: Coccinellidae) under High Temperature Stress

Abstract

In cotton-growing regions of northern Xinjiang, Propylaea quatuordecimpunctata (L.) (Coleoptera: Coccinellidae) is an important natural enemy that provides significant control of some pest hemipterans. Previous studies have shown that the survival and reproduction of P. quatuordecimpunctata differs under different high temperatures. However, its molecular mechanism for thermotolerance is poorly understood. In this study, transcriptome sequencing analysis was performed on P. quatuordecimpunctata, after its exposure to different temperatures (32–38 °C) for 24 h, using high-throughput sequencing technology. The results showed that the 35 vs. 38 °C groups had the most DEGs (1425), indicating that P. quatuordecimpunctata has more genes that can be mobilized under high temperature (38 °C). The results of functional analysis showed that the DEGs were mainly involved in “Oxidation–reduction process”, “Oxidoreductase activity”, “Metabolic pathways”, and “Small molecule metabolic processing” groups. We randomly selected DEGs (eleven P450 genes and one Hsp70 gene) of interest for qRT-PCR validation. The qRT-PCR results were consistent with the transcriptome data, indicating that the transcriptome data were reliable. In summary, these genes involved in these pathways play an important role in the resistance of P. quatuordecimpunctata to high temperature stress. Our study enriched our understanding of the molecular mechanism for thermotolerance in P. quatuordecimpunctata.