Identification and RNAi‐based function analysis of trehalase family genes in Frankliniella occidentalis (Pergande)

Abstract

BACKGROUNDInsects utilize trehalases (TREs) to regulate energy metabolism and chitin biosynthesis, which are essential for their growth, development, and reproduction. TREs can therefore be used as potential targets for future insecticide development. However, the roles of TREs in Frankliniella occidentalis (Pergande), a serious widespread agricultural pest, remain unclear.RESULTSThree TRE genes were identified in F. occidentalis and cloned, and their functions were then investigated via feeding RNA interference (RNAi) and virus‐induced gene silencing (VIGS) assays. The results showed that silencing FoTRE1‐1 or FoTRE1‐2 significantly decreased expression levels of FoGFAT, FoPGM, FoUAP, and FoCHS, which are members of the chitin biosynthesis pathway. Silencing FoTRE1‐1 or FoTRE2 significantly down‐regulated FoPFK and FoPK, which are members of the energy metabolism pathway. These changes resulted in 2‐fold decreases in glucose and glycogen content, 2‐fold increases in trehalose content, and 1.5‐ to 2.0‐fold decreases in chitinase activity. Furthermore, knocking down FoTRE1‐1 or FoTRE1‐2 resulted in deformed nymphs and pupae as a result of hindered molting. The VIGS assay for the three FoTREs revealed that FoTRE1‐1 or FoTRE2 caused shortened ovarioles, and reduced egg‐laying and hatching rates.CONCLUSIONThe results suggest that FoTRE1‐1 and FoTRE1‐2 play important roles in the growth and development of F. occidentalis, while FoTRE1‐1 and FoTRE2 are essential for its reproduction. These three genes could be candidate targets for RNAi‐based management and control of this destructive agricultural pest. © 2024 Society of Chemical Industry.

Effect of Three Novel Thiazolidiones on the Development, Reproduction, and Trehalase Activity of Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…The three new compounds-6d, 6e, and 6f-inhibited the trehalase activity in S. frugiperda larvae and downregulated the expression of both TRE1 and TRE2, consequently restricting the energy availability in the insects. Silencing the trehalase gene of Frankliniella occidentalis also led to significantly downregulated levels of enzymes associated with the energy metabolism pathway [44].…”

Dual Guardians of Immunity: FoRab10 and FoRab29 in Frankliniella occidentalis Confer Resistance to Tomato Spotted Wilt Orthotospovirus

“…The dsRNA primers (Table S1) targeting specific FoRab genes and the control gene (EGFP) were designed to minimize potential off-target effects using the Snapdragon tool (https://www.flyrnai.org/cgi-bin/RNAi_find_ primers.pl). RNAi experiments were performed according to protocols established in our laboratory, 52 and all dsRNAs were synthesized using the T7 Ribomax Express RNAi reagent (Promega, Madison). Approximately 400 first-instar nymphs were fed a 0.2 mL solution containing 0.5 μg/μL target gene dsRNA in a 10% sucrose solution for 24 h in a designated feeding chamber.…”