Imidacloprid is hydroxylated by Laodelphax striatellus CYP6AY3v2

Abstract

Laodelphax striatellus (Fallén) is one of the most destructive pests of rice, and has developed high resistance to imidacloprid. Our previous work indicated a strong association between imidacloprid resistance and the overexpression of a cytochrome P450 gene CYP6AY3v2 in a L. striatellus imidacloprid resistant strain (Imid-R). In this study, a transgenic Drosophila melanogaster line that overexpressed the L. striatellus CYP6AY3v2 gene was established and was found to confer increased levels of imidacloprid resistance. Furthermore, CYP6AY3v2 was co-expressed with D. melanogaster cytochrome P450 reductase (CPR) in Spodoptera frugiperda 9 (SF9) cells. A carbon monoxide difference spectra analysis indicated that CYP6AY3v2 was expressed predominately in its cytochrome P450 (P450) form, which is indicative of a good-quality functional enzyme. The recombinant CYP6AY3v2 protein efficiently catalysed the model substrate P-nitroanisole to p-nitrophenol with a maximum velocity (V ) of 60.78 ± 3.93 optical density (mOD)/min/mg protein. In addition, imidacloprid itself was metabolized by the recombinant CYP6AY3v2/nicotinamide adenine dinucleotide 2'-phosphate reduced tetrasodium salt (NADPH) CPR microsomes in in vitro assays (catalytic constant (K ) = 0.34 pmol/min/pmol P450, michaelis constant (K ) = 41.98 μM), and imidacloprid depletion and metabolite peak formation were with a time dependence. The data provided direct evidence that CYP6AY3v2 is capable of hydroxylation of imidacloprid and conferring metabolic resistance in L. striatellus.

Characterization of sulfoxaflor resistance in the brown planthopper, Nilaparvata lugens (Stål)

“…Similarly, overexpression of 12 P450 genes was observed in a laboratory‐selected imidacloprid‐resistant N. lugens strain, and CYP6AY1 , CYP6ER1 , CYP4CE1 and CYP6CW1 have been suggested to play important roles in imidacloprid resistance . The P450 genes associated with neonicotinoid resistance have also been reported in many other insects, such as CYP6AY3v2 and CYP353D1v2 in L. striatellus , CYP6G1 in D. melanogaster and CYP6CM1vQ in B. tabaci . Thus, it was reasonable to conclude that CYP15G1 , CYP6CS1 , CYP6CW1 , CYP6ER1 , CYP4C62 , CYP4DE1 , CYP417A1 and CYP419A1 were relevant for sulfoxaflor resistance in N. lugens .…”

“…38 The P450 genes associated with neonicotinoid resistance have also been reported in many other insects, such as CYP6AY3v2 and CYP353D1v2 in L. striatellus, CYP6G1 in D. melanogaster and CYP6CM1vQ in B. tabaci. 37,[39][40][41] Thus, it was reasonable to conclude that CYP15G1, CYP6CS1, CYP6CW1, CYP6ER1, CYP4C62, CYP4DE1, CYP417A1 and CYP419A1 were relevant for sulfoxaflor resistance in N. lugens. In the current study, after RNAi depressed the expression level of CYP6ER1, which had shown the greatest increase in expression (36.87-fold), the susceptibility of SFX-SEL (G 39 ) individuals to sulfoxaflor significantly increased (Fig.…”

Deltamethrin is metabolized by CYP6FU1, a cytochrome P450 associated with pyrethroid resistance, in Laodelphax striatellus

“…Among the tested insecticides, CYP439A1v3 (Miah MA, unpublished) and CYP6FU1 were demonstrated to metabolize only deltamethrin. CYP6AY3v2 could hydrolyze only imidacloprid, 16 and CYP353D1v2 could metabolize both imidacloprid 17 and buprofezin. 18 None of the tested CYP genes could degrade chlorpyrifos.…”

An overexpressed cytochrome P450 CYP439A1v3 confers deltamethrin resistance in Laodelphax striatellus Fallén (Hemiptera: Delphacidae)

“…The cytochrome P450 genes CYP353D1v2 , CYP6FU1 , CYP6AY3v2 , and CYP439A1v3 were previously reported to be overexpressed in a deltamethrin resistant strain in L. striatellus , which also showed cross‐resistance to imidacloprid and chlorpyrifos (Xu et al, ). Accordingly, these genes have been functionally expressed (Elzaki et al, ; R. Wang et al, ) and tested for their capability for the degradation of common insecticides. Among the overexpressed P450s (from the deltamethrin‐resistant strain of L. striatellus ), CYP353D1v2 , CYP6FU1 , and CYP6AY3v2 were already confirmed for their catalytical role to metabolize various insecticides.…”

“…The first three P450s have been functionally expressed in vitro and tested for insecticide degradation. Among these three P450s, CYP353D1v2 was found capable of catalyzing the degradation of imidacloprid (Elzaki, Miah, Wu, et al, ) and buprofezin (Elzaki, Miah, & Han, ), whereas CYP6AY3v2 catalyzed imidacloprid degradation (R. Wang et al, ). Only CYP6FU1 was found capable of deltamethrin degradation (Elzaki, Miah, Peng, et al, ).…”