Transcriptome response mediated by cold stress in Sitobion miscanthi

To reveal the adaptation mechanisms of Sitobion miscanthi to low temperature, third instar larvae were analyzed by transcriptome sequencing after exposure to low temperature (-7 ℃, T group) or normal temperature (22 ℃, CK group) for three hours. Gene function annotation and related pathway enrichment analyses were performed. The expression levels of randomly selected S. miscanthi chilling resistance-related genes were also determined by quantitative real-time PCR (qRT-PCR) to verify the sequencing results. A total of 28 333 unigenes were sequenced and assembled, and 8 842 were annotated in GO. Compared with the control group, 936 unigenes were differentially expressed after low temperature exposure (508 were up-regulated and 428 were down-regulated). GO functional analysis and KEGG enrichment analysis revealed that the differentially expressed genes mainly focused on carbon metabolism, amino acid biosynthesis, and valine, leucine, and isoleucine degradation pathway. Among these genes, trehalose, heat shock protein, and sex determination protein genes were significantly up-regulated while myrosinase genes were significantly down-regulated. The qRT-PCR results for six randomly selected differentially expressed genes were consistent with the transcriptome sequencing results. This study provides a scientific basis for exploring the cold tolerance mechanism of S. miscanthi-related genes.