A double chaperone function of the sHsp genes against heat-based environmental adversity in the soil-dwelling leaf beetles

Small heat shock proteins (sHsps), which are constitutively expressed in the absence of stress during development in many organisms, have been correlated with not only enhanced thermoresistance but also the developmental, tissue-, and cell-specific induction and expression. This study demonstrates the constitutive sHsps 21 and 23 of an entomoresouce, the leaf beetle, Gastrophysa atrocyanea, display a double chaperone function in vitro. The RNAi suppression of two sHsp genes in adults resulted in decreased thermoresistance. A strong correlation was observed between the in vitro chaperone function and in vivo thermotolerance analysis, and the results support a possible double chaperone function critical for the survival of the leaf beetles against higher temperatures.