Resistance monitoring and cross-resistance role of CYP6CW1 between buprofezin and pymetrozine in field populations of Laodelphax striatellus (Fallén)

Pest Management Science

et al. 2021

BACKGROUND Pymetrozine is commonly used for the control of Nilaparvata lugens, and resistance to pymetrozine has been frequently reported in the field populations in recent years. However, the mechanism of brown planthopper resistance to pymetrozine is still unknown. RESULTS In this study, a pymetrozine‐resistant strain (PMR) was established, and the potential biochemical resistance mechanism of N. lugens to pymetrozine was investigated. Pymetrozine was synergized by the inhibitor piperonyl butoxide (PBO) in the PMR with 2.83‐fold relative synergistic ratios compared with the susceptible strain (Sus). Compared with the Sus, the cytochrome P450 monooxygenase activity of PMR was increased by 1.7 times, and two P450 genes (NlCYP6CS1 and NlCYP301B1) were found to be significantly overexpressed more than 6.0‐fold in the PMR. Pymetrozine exposure induced upregulation of NlCYP6CS1 expression in the Sus, but the expression of NlCYP301B1 did not change significantly. In addition, RNA interference (RNAi)‐mediated suppression of NlCYP6CS1 gene expression dramatically increased the toxicity of pymetrozine against N. lugens. Moreover, transgenic lines of Drosophila melanogaster expressing NlCYP6CS1 were less susceptible to pymetrozine, and had a stronger ability to metabolize pymetrozine. CONCLUSIONS Taken together, our findings indicate that the overexpression of NlCYP6CS1 is one of the key factors contributing to pymetrozine resistance in N. lugens. And this result is helpful in proposing a management strategy for pymetrozine resistance.

Section: Discussionmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Mechanism of metabolic resistance to pymetrozine in Nilaparvata lugens: over‐expression of cytochrome P450 CYP6CS1 confers pymetrozine resistance

Wang

Tao

Pest Management Science

et al. 2021

“…A series of P450s in CYP3 and CYP4 clades are induced or overexpressed in planthoppers and involved in the metabolism of insecticides, such as CYP4CE1 , CYP6AY1, and CYP6CW1 [ 9 , 10 , 11 ]. Metabolic resistance mediated by the P450s has been considered as the dominant factor for insecticide resistance in the field populations of planthoppers [ 12 , 13 , 14 ]. A previous study showed that the genetic variants of CYP2E1 and CYP1A1 resulted in the susceptibility to chronic Hepatitis B virus infection [ 15 ], suggesting P450s in CYP3 and CYP4 clades might be involved in the regulation of virus infection.…”

Section: Introductionmentioning

confidence: 99%

“…Imidacloprid is a representative neonicotinoid insecticide and can disturb the nervous system of insects [ 10 , 11 ], while deltamethrin is a modulator of nerve sodium channels in insects [ 24 ]. Pymetrozine is a fast-acting and selective inhibitor of the feeding of sap-sucking insects [ 14 ]. Buprofezin is an insect growth regulator and can interfere with metabolism and inhibit chitin synthesis in insects [ 14 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cytochrome P450 Monooxygenases CYP6AY3 and CYP6CW1 Regulate Rice Black-Streaked Dwarf Virus Replication in Laodelphax striatellus (Fallén)

Zhao

Zhou

et al. 2021

Viruses

The small brown planthopper, Laodelphax striatellus (Fallén), is an important agricultural pest that causes significant losses by sucking and transmitting multiple plant viruses, such as rice black-streaked dwarf virus (RBSDV). Insecticides are commonly used to control planthoppers and cause the induction or overexpression of cytochrome P450 monooxygenases (P450s) from the CYP3 and CYP4 clades after insecticide application. However, little is known about the roles of insecticides and P450s in the regulation of viral replication in insects. In this study, RBSDV-infected L. striatellus were injected with imidacloprid, deltamethrin, pymetrozine, and buprofezin, respectively. The insecticide treatments caused a significant decrease in RBSDV abundance in L. striatellus. Treatment of piperonyl butoxide (PBO), an effective inhibitor of P450s, significantly increased the RBSDV abundance in L. striatellus. Fourteen P450 candidate genes in the CYP3 clade and 21 in the CYP4 clade were systematically identified in L. striatellus, and their expression patterns were analyzed under RBSDV infection, in different tissues, and at different developmental stages. Among the thirty-five P450 genes, the expression level of CYP6CW1 was the highest, while CYP6AY3 was the lowest after RBSDV infection. Knockdown of CYP6CW1 and CYP6AY3 significantly increased the virus abundance and promoted virus replication in L. striatellus. Overall, our data reveal that CYP6CW1 and CYP6AY3 play a critical role in the regulation of virus replication in L.striatellus.

Inheritance and fitness cost of buprofezin resistance in a near‐isogenic, field‐derived strain and insecticide resistance monitoring ofLaodelphax striatellusin China

Zeng

Liu

Pest Management Science

et al. 2022

BACKGROUND Laodelphax striatellus is one of the most destructive pests of rice and other cereal crops. Chemical control is still the most efficient way to control this pest, but insecticide resistance always threatens this approach. RESULTS Monitoring data (2003–2020) showed that Chinese field populations of L. striatellus developed high‐level buprofezin resistance within the first four years. This high‐level resistance to buprofezin was stable for about ten years and persisted even when buprofezin selection pressure was absent. An established near‐isogenic strain (YN‐NIS) with 90.8‐fold resistance to buprofezin had resistance inheritance of autosomal and incomplete dominance, and the resistance was controlled by multiple genes with no obvious fitness costs (relative fitness of 0.8707). Furthermore, the susceptibility of 29 field populations to another seven insecticides (2014–2020) showed that: (i) low‐level resistance to pymetrozine, dinotefuran, sulfoxaflor and thiamethoxam was first detected in 2014 (eight years after introduction), 2016 (three years after), 2017 (four years after) and 2019 (19 years after), respectively, (ii) moderate resistance levels to chlorpyrifos were found for all populations across multiple years, and (iii) no resistance was detected for nitenpyram and triflumezopyrim. CONCLUSION The fast buprofezin resistance development in L. striatellus would be caused by incomplete dominant resistance with almost no fitness cost in the resistant strain. Nitenpyram and triflumezopyrim showed no resistance and can be used as the main insecticide for the control of L. striatellus. These findings provide key fundamental information for controlling L. striatellus.