Genome-wide characterization of heat shock protein (HSP) genes in Tuta (Phthorimaea) absoluta: insights into thermal stress response

Abstract The tomato leafminer Tuta (Phthorimaea) absoluta (Lepidoptera: Gelechiidae) is a highly destructive invasive pest of tomato. Heat shock proteins (HSPs) are key molecular chaperones that mediate insect responses to environmental stress. Despite their central role, a comprehensive characterization of HSP genes in T. absoluta has been lacking. Here, we performed a genome-wide identification and characterization of T. absoluta HSP genes. In total, 58 HSP genes were identified, including 23 sHSPs, 10 HSP60s, 20 HSP70s, and five HSP90s. Coding sequence lengths ranged from 405 to 3,741 base pairs, encoding proteins of 103–475 amino acids. Gene structure analysis showed that 58% of these HSPs lacked introns. Chromosomal mapping revealed multiple tandem duplications, particularly within the sHSP and HSP70 families. Phylogenetic analysis demonstrated that T. absoluta HSPs clustered by subfamily with strong conservation. RT-qPCR revealed significant upregulation of several HSP70 genes (TaHSP70-8, TaHSP70-9, TaHSP70-11, TaHSP70-12, TaHSP70-14, TaHSP70-17, and TaHSP70-18) under high-temperature stress. These findings provide the first comprehensive catalog of HSPs in T. absoluta, establishing a molecular framework for future studies on stress adaptation and offering insights for pest management strategies.