Modulation of thermal tolerance by heat or cold hardening in the hematophagous insect Rhodnius prolixus: the role of heat shock proteins

SCHILMAN, P.E.; COLECCHIA-CORSO, M.L.; PONTES, G.; LATORRE-ESTIVALIS, J.M.; PEREIRA, M.H.

Congreso; XXVI International Congress of Entomology (ICE 2022); 2022

Temperature is an important abiotic factor affecting many physiological processes in ectotherms, including insects. The thermal stress produced by extreme temperatures can have deleterious effects on insects. So, there are many mechanisms to withstand it including the production of heat shock proteins (HSPs). We investigated the effect of a moderate heat or cold shock on thermotolerance of the hematophagous insect Rhodnius prolixus, as well as the role of HSPs. For that, groups of insects were exposed 1 h to two hardening temperatures (10 or 37°C) or keep at 25°C (control group), and thereafter standard thermotolerance tests, such as, critical thermal maxima (CTmax) and critical thermal minimum (CTmin) were performed. Results showed that heat hardening (37°C) increase thermotolerance by affecting both, CTmax and CTmin. In the same way, cold hardening (10°C) increased tolerance to high and low temperatures, which strongly suggest that both, heat and cold hardening could induce a thermotolerance improvement. In addition, HSP70/HSP90 RNAi knockdown insects showed lower resistance to low and high temperatures compared with their controls. These results provide further insight into the physiological adaptations of hematophagous insects to harsh environmental conditions.