First evidence that interactions of Heat Shock Protein 20 with reproduction-related proteins aid in fertility recovering from heat stress in Monochamus alternatus

Abstract

Abstract Insects, as ectotherms, are highly susceptible to temperature increases due to global climate change, with heat tolerance being crucial for their survival. Heat Shock Proteins (HSPs) play a vital role in this tolerance, preventing protein denaturation. However, the interaction between HSPs and their native substrate proteins remains underexplored. This study examined the effects of heat stress on Monochamus alternatus, a significant pest in forestry, focusing on its reproductive heat tolerance and recovery. Heat stress was found to reduce fecundity, fertility, mating, and oviposition behaviors, alongside impairing the development and viability of reproductive organs and sperm. Remarkably, all reproductive parameters of M. alternatus recovered within four weeks post-exposure. To investigate the recovery mechanisms, we identified ten reproduction-related proteins as candidate substrate protein of an HSP protein in M. alternatus using immunoprecipitation coupled with mass spectrometry analysis. Heat stress inhibited the transcription of these reproduction-related genes, thereby adversely affecting reproductive parameters. However, the induction of HSP20s transcription in response to heat stress appeared to facilitate the refolding of these critical reproduction-related proteins during the recovery phase, preventing lasting reproductive damage. Overall, this study suggested that while M. alternatus populations might be vulnerable to climate-induced temperature increases, their fertility had the capacity to recover, mediated by HSPs’ interaction with reproduction-related genes. These findings offered profound insights into insect heat tolerance and recovery, expanding our understanding of HSP20 proteins’ biological functions.