Temperature-dependent expression profiling of 16 HSP genes across developmental stages in Frankliniella occidentalis

The western flower thrips (Frankliniella occidentalis), as a globally invasive pest, exhibits temperature adaptation mechanisms closely associated with its heat shock protein (HSP) regulatory network. Although some Hsps have been identified, the response patterns to temperature stress across different developmental stages remain unclear. This study presents the first systematic analysis of temperature response characteristics of 16 Hsps (covering Hsp70/90/60/40, sHsp and Hop families) in second-instar larvae, pupae and adults. Using qRT-PCR, we examined expression patterns across a temperature gradient (-10 to 41 °C) and statistically determined both the onset stress temperature (T_on) and peak expression temperature (T_max). Our findings reveal that: (1) Stage-specific Hsps expression profiles reflect dynamic energy allocation between developmental needs and stress defense; (2) Developmental variations in thermal response ranges indicate differences in heat sensitivity and involved genes; (3) Functional division between constitutively highly expressed genes (e.g., Fohsc701) and inducible genes (e.g., FoHSP70) underpins the stress response network. We postulate a collaborative HSP model: sHsps stabilize misfolded proteins as the first line of defense, while Hsp70/Hsp40 and Hsp90 facilitate ATP-dependent refolding, and Hsp60/Hsp10 mediates mitochondrial protein assembly. These results elucidate the role of Hsps in F. occidentalis development and temperature adaptation, offering a theoretical basis for temperature-based control strategies.