Cloning and Functional Verification of CYP408A3 and CYP6CS3 Related to Chlorpyrifos Resistance in the Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

Abstract

The white-back planthopper (WBPH), Sogatella furcifera, mainly harms rice and occurs in most rice regions in China and Asia. With the use of chemical pesticides, S. furcifera has developed varying degrees of resistance to a variety of pesticides. In our study, a chlorpyrifos-resistant population (44.25-fold) was built through six generations of screening with a sublethal dose of chlorpyrifos (LD50) from a field population. The expression levels of ten selected resistance-related P450 genes were analyzed by RT-qPCR and found that CYP408A3 and CYP6CS3 were significantly more expressed in the third instar nymphs of the XY17-G5 and XY17-G6 populations, about 25-fold more than the Sus-Lab strain, respectively (p < 0.01). To elucidate their molecular function in the development of resistance towards chlorpyrifos, we cloned two P450 full lengths and predicted their tertiary protein structures. CYP408A3 and CYP6CS3 were also downregulated after injecting dsCYP408A3, dsCYP6CS3, or their mixture compared to the control group. Moreover, the mortality rates of the dsCYP6CS3 (91.7%) and the mixture injection treatment (93.3%) treated by the LC50 concentration of chlorpyrifos were significantly higher than the blank control group (51.7%) and dsCYP408A3 injection treatment (69.3%) at 72 h (p < 0.01). Meanwhile, the P450 enzyme activities in the dsRNA treatments were lower than that in the control (XY17-G6) (p < 0.01). Therefore, the P450 gene CYP6CS3 may be one of the main genes in the development of chlorpyrifos resistance in S. furcifera.

Metabolic Resistance of Sogatella furcifera (Hemiptera: Delphacidae) toward Pymetrozine Involves the Overexpression of CYP6FJ3

“…13 Research on the resistance mechanism of S. f urcifera mainly focuses on enhancing insecticide metabolism mediated by overexpression of detoxification genes, such as CarE and P450. 14,15 P450 enzymes in the CYP3 clade and CYP4 clade play a crucial role in the development of metabolic resistance against insecticides. 16,17 Wang et al 18 found that the metabolic resistance of S. furcifera toward sulfoxaflor was related to the overexpression of CYP6FD1 and CYP4FD2.…”

“…Furthermore, several other P450 enzymes have been identified as key factors in insecticide resistance, including CYP6AY1 and CYP6ER1 in Nilaparvata lugens; 19 CYP6AY3, CYP6CS3, and CYP6FJ3 in the CYP3 clade, as well as CYP417A4, CYP4DD1, and CYP4C77 in the CYP4 clade, have been found to be up-regulated and induced by imidacloprid or nitromethyleneimidazole. 20 Ruan et al 15 identified 12 potential P450 genes that may be involved in the insecticide resistance of S. furcifera, and further investigations revealed that CYP6ER4 plays a significant role in the metabolic resistance to chlorpyrifos. Pymetrozine can be hydroxylated by CYP6CM1 in Bemisia tabaci, which has conferred neonicotinoid resistance; 21 Wang et al 22 also found that the overexpression of CYP6CS1 in N. lugens was involved in resistance toward pymetrozine.…”

“…The resistance mechanisms of pests mainly include increasing detoxification enzyme activity (carboxylesterase enzyme (CarE), glutathione s-transferase enzyme (GST), and cytochrome P450 enzyme (P450)) , and decreasing the affinity between the insecticide and its target . Research on the resistance mechanism of S. furcifera mainly focuses on enhancing insecticide metabolism mediated by overexpression of detoxification genes, such as CarE and P450. , P450 enzymes in the CYP3 clade and CYP4 clade play a crucial role in the development of metabolic resistance against insecticides. , Wang et al found that the metabolic resistance of S. furcifera toward sulfoxaflor was related to the overexpression of CYP6FD1 and CYP4FD2 . Furthermore, several other P450 enzymes have been identified as key factors in insecticide resistance, including CYP6AY1 and CYP6ER1 in Nilaparvata lugens ; CYP6AY3 , CYP6CS3 , and CYP6FJ3 in the CYP3 clade, as well as CYP417A4 , CYP4DD1 , and CYP4C77 in the CYP4 clade, have been found to be up-regulated and induced by imidacloprid or nitromethyleneimidazole .…”

Juvenile Hormone Synthesis Pathway Gene SfIPPI Regulates Sogatella furcifera Reproduction

“…S. furcifera is also a transmission vector for the southern rice black-streaked dwarf virus [18], which negatively affects rice production and leads to severe economic losses [19][20][21]. At present, S. furcifera is mainly controlled using chemical insecticides, but their excessive use not only negatively impacts the environment and natural enemies of S. furcifera, but also lead to insecticide resistance and other problems [22][23][24]. Thus, to achieve a sustainable pest management, it is imperative to find an environmentally friendly and efficient method to control S. furcifera populations.…”