Transcriptional profiling of MED Bemisia tabaci exposed to thermal stress and verification of HSP70 expression

Temperature changes impact agricultural production and also influence the behavior and community structure of many insect species. Bemisia tabaci, is an invasive and destructive pest with at least 44 cryptic species and occurring in over 100 countries and regions. In this study, transcriptional profiling was used to evaluate the response of the Mediterranean (MED) cryptic species B. tabaci exposed to cold and hot temperature stress. In response to cold stress, 3,024 unigenes were differentially expressed and mapped to 39 Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathways. A total of 4,437 unigenes were differentially expressed during heat stress, and these represented 18 KEGG enrichment pathways. Quantitative RT-PCR was used to determine the relative expression level of the 11 HSP70 fragments; these were significantly up-regulated during high temperature stress relative to the control group that was maintained at 26 degrees C. In conclusion, the transcriptome data indicated that B. tabaci responds to thermal stress via multiple genes and networks. Furthermore, HSP70 plays an important role in stress tolerance of the MED B. tabaci, especially during heat stress.