Transcription factor AhR regulates glutathione S-transferases (GSTs) conferring resistance to<i>lambda</i>-cyhalothrin in<i>Cydia pomonella</i>

Four P450s were reported to be important for imidacloprid resistance in Nilaparvata lugens, a major insect pest on rice, which was confirmed in this study in an imidacloprid-resistant strain (ImiR). Here we found that only two (CYP4CE1 and CYP6ER1) from these four P450 genes were overexpressed in a nitenpyram-resistant strain (NitR) when compared to a susceptible strain (SUS). CYP4CE1 RNAi reduced nitenpyram and imidacloprid resistance in NitR and ImiR strains, with a greater reduction in nitenpyram resistance. The transcription factor FoxO mediated nitenpyram resistance in NitR and ImiR strains, but it was not differentially expressed among strains. The potential reason for the differential regulation of FoxO on CYP4CE1 expression was mainly from sequence differences in the CYP4CE1 promoter between susceptible and resistant insects. In six FoxO response elements predicted in the CYP4CE1 promoter, the single-nucleotide polymorphisms were frequently detected in over 50% of NitR and ImiR individuals. The luciferase reporter assays showed that two mutations, −650T/G and −2205T/A in two response elements at the positions of −648 and −2200 bp, mainly contributed to the enhanced regulation on CYP4CE1 expression by FoxO in resistant insects. The frequency was over 69% for both −650T/G and −2205T/A detected in NitR and ImiR individuals but less than 20% in SUS insects. In conclusion, CYP4CE1 overexpression importantly contributed to nitenpyram resistance in N. lugens, and two mutations in the CYP4CE1 promoter of resistant insects led to an enhanced regulation on CYP4CE1 expression by FoxO.

Section: ■ Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 96%

Two Point Mutations in CYP4CE1 Promoter Contributed to the Differential Regulation of CYP4CE1 Expression by FoxO between Susceptible and Nitenpyram-Resistant Nilaparvata lugens

Zhang,

Lin,

Yang

et al. 2024

“…Following the injection of dsCpGPCR70, an assessment was conducted on the expression levels of detoxification genes, specifically selected as potential candidate genes known to play a role in the metabolic of lambdacyhalothrin in C. pomonella. 7 The result showed a notable decrease in mRNA levels of CpGSTs2 (Figure 6A) and CpCYP9A121 (Figure 6B) subsequent to the interference caused by CpGPCR70, in comparison with the control group. The enzymatic assay showed that the P450 enzyme activity decreased significantly at 12 h after the injection of dsCpGPCR70 (Figure 6D), while there was no significant difference of the GST enzyme activity compared with the control (Figure 6C).…”

Section: Regulation Of Detoxification Genes Bymentioning

confidence: 91%

“…The method of RNA interference (RNAi) has been established and applied in our laboratory. 7 Immediately after injection, the samples were collected and promptly treated with liquid nitrogen and subsequently stored at −80 °C.…”

Section: Identification Of Gpcrsmentioning

confidence: 99%

“…Limited research has demonstrated that the transcription factor aryl hydrocarbon receptor (AhR) regulates several key resistance-related genes (CpGSTe3, CpCYP9A121, and CpCYP9A122) in C. pomonella. 7 G protein-coupled receptors (GPCRs), which are known as the most diverse superfamily of membrane receptors, are composed of N-terminal and C-terminal regions alongside a highly conserved seven-transmembrane (7TM) core backbone. 8 Functioning as the primary signaling receptors, GPCRs play critical regulatory functions across a range of physiological processes, including cellular metabolism, hormone secretion, behavioral and emotional regulation, and the immune system.…”

Section: Introductionmentioning

confidence: 99%

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Identification of G Protein-Coupled Receptors (GPCRs) Associated with Lambda-Cyhalothrin Detoxification in Cydia pomonella

Liu,

Hu,

et al. 2023

While previous studies have reported G protein-coupled receptor (GPCR)-mediated insecticide resistance in various arthropods, the understanding of GPCR-associated resistance mechanisms in Cydia pomonella remains limited. In this study, a total of 95 CpGPCR genes categorized into four families were identified in C. pomonella. Results revealed high expression levels of the majority of the CpGPCRs during the first larval stage and in the head of C. pomonella. Exposure to lambda-cyhalothrin significantly increased the expression of 15 CpGPCRs, including CpGPCR70, which is highly expressed in all larval stages and shows the highest expression in the midgut. RNA interference (RNAi) demonstrated that downregulation of CpGPCR70 leads to reduced expression of key resistance-related genes and a decreased tolerance of larvae to lambda-cyhalothrin. These findings indicate that CpGPCR70 plays a crucial role in regulating the expression of detoxifying genes involved in lambda-cyhalothrin resistance, offering valuable insights for the development of more effective pest control strategies.

miR-317-3p and miR-283-5p Play a Crucial Role in Regulating the Resistance to Indoxacarb in Spodoptera frugiperda by Targeting GSTs4

Wu,

Lv,

Guo

et al. 2024

Spodoptera frugiperda is primarily controlled through chemical insecticides. Our RNA-seq data highlight the overexpression of GSTs4 in indoxacarb-resistant S. frugiperda. However, the exact role of GSTs4 in indoxacarb resistance and its regulatory mechanisms remains elusive. Therefore, we investigated the functional role of GSTs4 in S. frugiperda and explored the underlying post-transcriptional regulatory mechanisms. GSTs4 was highly overexpressed (27.6-fold) in the indoxacarb-resistant strain, and GSTs4 silencing significantly increases the susceptibility of S. frugiperda to indoxacarb, increasing mortality by 27.3%. miR-317-3p and miR-283-5p can bind to the 3′UTR of GSTs4, and the targeting relationship was confirmed by dual-luciferase reporter assays. Injecting miR-317-3p and miR-283-5p agomirs reduces GSTs4 levels by 64.8 and 42.3%, respectively, resulting in an increased susceptibility of S. frugiperda to indoxacarb. Conversely, the administration of miR-317-3p and miR-283-5pantagomirs increases GSTs4 expression and reduces larval susceptibility to indoxacarb. These findings demonstrate that miR-317-3p and miR-283-5p contribute to indoxacarb resistance in S. frugiperda by regulating the overexpression of GSTs4.