The hsp/co-chaperone network in environmental cold adaptation of chilo suppressalis

Authors: JIANG, FAN - Huazhong Agricultural University; CHANG, GUOFENG - Huazhong Agricultural University; LI, ZHENZHEN - Huazhong Agricultural University; ABOUZAID, MOSTAFA - Huazhong Agricultural University; DU, XIAOYONG - Huazhong Agricultural University; Hull, Joe; MA, WEIHUA - Huazhong Agricultural University; LIN, YONGJUN - Huazhong Agricultural University

Submitted to: International Journal of Biological Macromolecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2021
Publication Date: 9/30/2021
Publication URL: https://handle.nal.usda.gov/10113/7465775
Citation: Jiang, F., Chang, G., Li, Z., Abouzaid, M., Du, X., Hull, J.J., Ma, W., Lin, Y. 2021. The hsp/co-chaperone network in environmental cold adaptation of chilo suppressalis. International Journal of Biological Macromolecules. 187:780-788. https://doi.org/10.1016/j.ijbiomac.2021.07.113.
DOI: https://doi.org/10.1016/j.ijbiomac.2021.07.113

Interpretive Summary: The physiological processes that govern the behavior and fitness of organisms are significantly impacted by their thermal environment. This is particularly true for insects in temperate and polar regions where the colder conditions can sufficiently lower body temperatures to disrupt physiological performance and homeostatic maintenance. Consequently, the ability of insects to adapt to low temperatures is critical. For many insects, this adaptation involves a group of proteins termed heat-shock proteins (HSPs) that facilitate the re-folding of proteins whose structures have been disrupted by thermal stresses associated with excessive heat or cold. To begin to understand how the striped stem borer (Chilo suppressalis), a significant pest of rice, has adapted to colder geographic regions its genome was searched for HSP genes. Expression of the respective genes in response to varying degrees of cold stress was subsequently experimentally assessed. A total of 27 genes were found to be up regulated in response to cold with the expression of some genes linked with cold acclimation. The study has provided baseline information on which genes may be necessary for striped stem borer survival in colder temperatures.

Technical Abstract: Winter cold is one of the major environmental stresses for ectotherm species. Chilo suppressalis, a notorious lepidopteran pest of rice, has a wide geographic region that includes temperate zones with severe environmental conditions. Although C. suppressalis exhibits remarkable cold tolerance, its cold-adaptation mechanisms remain unclear. Here, we used bioinformatics approaches to evaluate transcript levels of genes comprising the C. suppressalis heat shock protein (HSP)/co-chaperone network in response to cold-induced stress. Using all such genes identified in the C. suppressalis genome, we experimentally examined the corresponding transcript levels under cold-acclimation or intermittent cold-shock stresses in diapause and non-diapausing larvae. In total, we identified 19 HSPs and 8 HSP co-chaperones in the C. suppressalis genome. Nine (hsp90, hsp75, hsp70, hsp40, small hsp, activator of 90 kDa heat shock protein ATPase-like, heat shock factor, heat shock factor binding protein 1-like and HSPB1-associated protein 1) were highly cold-inducible and likely comprise the principal cold-response HSP/co- chaperone network in C. suppressalis. We also found that transcriptional regulation of the HSP/co-chaperone networks response differs between cold-acclimation and short-term cold-shock. Moreover, activation of the HSP/co-chaperone network depends on the diapause state of overwintering larvae and cold acclimation may further increase larval cold tolerance. These results provide key new insights in the cold-adaptation mechanisms in C. suppressalis.