Glyphodes pyloalis Raw sequence reads
Cd is the most serious heavy metal pollutant in agricultural soil of China which can affect the growth, development and physiological processes of herbivorous insects through the food chain. Glyphodes pyloalis Walker (G. Pyloalis) is one of the most important pests of mulberry, but the effects of Cd stress on G. pyloalis has not been reported yet. To understand the response mechanism of G. pyloalis underlying the Cd, we exposed the G. pyloalis larvae to three Cd concentrations (0, 3.89 and 51.69 mg/kg; CK, LD and HD, respectively), measured the survival rate, pupation rate, pupal weight and adult emergence rate of the G. pyloalis and tested the activities of alkaline phosphatase(AKP), acid phosphatase(ACP) and glutathione S-transferase (GST), then used RNA-seq to explore molecular mechanism of Cd to G. pyloalis larvae. The results revealed that Cd exposure changed the pupal weight and the activities of AKP, ACP and GST in G. pyloalis, and caused significant adverse effects at the molecular level on detoxification and metabolism, with concentration and time differences. Transcriptome analysis showed that compared with the CK, a total of 63 differentially expressed genes (DEGs) were identified in LD exposure, including 24 upregulated and 39 downregulated candidates; in CK versus HD groups, 395 upregulated DEGs and 436 downregulated DEGs were identified for a total of 831 DEGs and the expression patterns of 12 detoxification-related genes were verified by qPCR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment indicated that detoxification enzyme genes were significantly expressed in peroxisome and drug metabolism-cytochrome P450 pathway. The results of gene annotation and quantitative real-time PCR showed that high concentration of Cd significantly stimulated the expression of metabolic detoxification enzyme genes such as GST.