Expression analysis of HSP70 gene in response to environmental stress in Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

This study aimed to investigate the role of heat shock proteins in the response of Spodoptera frugiperda to environmental stress. Four Hsp70 genes of S. frugiperda were cloned using reverse transcription–polymerase chain reaction (RT-PCR) and their sequence characteristics were characterized using bioinformatics analysis. RT-qPCR was used to detect Hsp70 at different developmental stages, in different tissues, and under varying environmental stresses (45°C, 36°C, 4°C, ultraviolet-A, and emamectin benzoate) to quantify the relative expression of this gene. Four Hsp70 genes were obtained by cloning, namely SfHsp70-1, SfHsp70-2, SfHsp70-3, and SfHsp70-like, which encode 653, 686, 638, and 627 amino acids, respectively, and all contain the three Hsp70 family signature sequences. Neighbor-joining (NJ) method was used to construct phylogenetic tree, and four Hsp70 of the S. frugiperda species were clustered with Lepidoptera. The results of real-time PCR showed that the SfHsp70s gene was specifically expressed in different tissues at different developmental stages and its expression increased considerably under nearly all environmental stresses in adults. This study shows that the SfHsp70 gene contributes to a large extent to the resistance of S. frugiperda to environmental stress.