Identification of SNPs involved in regulating a novel alternative transcript of P450 CYP6ER1 in the brown planthopper

Abstract

Cytochrome P450-mediated metabolic resistance is one of the major mechanisms involved in insecticide resistance. Although the up-regulation of cytochrome P450 plays a vital role in insecticide metabolism, the molecular basis for the transcriptional regulation of cytochrome P450 remains largely unknown. The P450 gene CYP6ER1, has been reported to confer imidacloprid resistance to the brown planthopper, Nilaparvata lugens. Here, we identified a novel alternative transcript of CYP6ER1 (transcript A2) that had different expression patterns between resistant and susceptible populations, and was more stable after insecticide induction. The promoter of this transcript was sequenced and multiple single nucleotide polymorphisms (SNPs) were detected in individuals from susceptible and resistant field-collected populations. Resistant alleles of four SNPs were found to significantly enhance the promoter activity of the CYP6ER1 transcript A2. Electrophoretic mobility shift assays (EMSAs) revealed that these SNPs might regulate the binding of transcription factors to the promoter. Our findings provide novel evidence regarding the transcriptional regulation of a metabolic resistance-related gene and may be useful to understand the resistance mechanism of N. lugens in the field.

Activator protein‐1 mediated CYP6ER1 overexpression in the clothianidin resistance of Nilaparvata lugens (Stål)

“…Specific primers for the CYP6ER1 promoter (Listed in Table S1) were designed based on the reported sequence 15 . The sequences of the CYP6ER1 promoter were amplified using LA Taq (Takara, Japan).…”

“…CYP6AY1 and CYP6ER1 exhibit high expression levels in imidacloprid‐resistant populations, and their recombinant proteins metabolize imidacloprid in vitro 12,13 . Moreover, promoter polymorphisms discovered in CYP6AY1 and CYP6ER1 may be used to investigate their transcriptional regulation 14,15 . However, the detailed regulatory mechanisms responsible for the overexpression of CYP6ER1 and CYP6AY1 in neonicotinoid resistance, such as the presence of specific transcription factors, remain unknown.…”

Full length sequencing reveals novel transcripts of detoxification genes along with related alternative splicing events and lncRNAs in Phyllotreta striolata

“…The three alternative splicing events of P450s were identified in 5'-UTR, 3'UTR, and CDS, respectively, which might change the translation of mRNA or directly affect the enzyme activity. In the Nilaparvata lugens, a novel alternative transcript of CYP6ER1 was found important for imidacloprid resistantance [48]. In Drosophila, an alternative splicing event in ABC gene MDR49 was associated with DDT resistance [49].…”

Insecticide Resistance in the Brown Planthopper, Nilaparvata lugens (Stål): Mechanisms and Status in Asian Countries

“…In two nicotinic acetylcholine receptor (nAChR) subunits, point mutations (Y151S) have been identified in association with imidacloprid resistance in N. lugens (Zewen et al, 2005). However, the mutations in target site have only been found in laboratory selected imidacloprid resistant-strain and never been reported in resistant field populations of N. lugens (Zewen et al, 2005;Liang et al, 2018;Sanada-Morimura et al, 2019). For this reason most of the recent research only emphasizes complex metabolic resistance mechanisms that found both in lab selected strain and field collected N. lugens.…”

“…The involvement of a metabolic enzyme in detoxifying insecticide has proved by measuring the enhanced levels of detoxifying enzyme activities in insects. The elevated activities of metabolic enzymes P450, esterases (EST) and glutathione S-transferases (GST) have been reported in several insect species resistant to insecticides (Bass & Field, 2011;Liang et al, 2018). Through the synergistic and enzymatic assay, increased activity of detoxifying P450 enzyme has been found in many insects in response to neonicotinoids insecticides (Chen, Shan, Liu, Shi, & Gao, 2019).…”