Wolbachia enhances expression of NlCYP4CE1 in Nilaparvata lugens in response to imidacloprid stress

The brown planthopper,Nilaparvata lugens, is one of the main insect pests of rice. TheN. lugensgeneNlCYP4CE1encodes cytochrome P450 monooxygenase (P450), which is a key enzyme in the metabolism of the insecticide imidacloprid. Previous research has suggested that the expression ofNlCYP4CE1is induced by imidacloprid stress, but the effect of bacterial symbionts on its expression has not been determined. The results of this study show that exposure to subtoxic imidacloprid changed the structure of the bacterial symbiont community inN. lugens. Specifically, the total bacterial content increased, but the bacterial species diversity significantly decreased.Wolbachiaaccounted for the largest proportion of bacteria inN. lugens; its abundance significantly increased after subtoxic imidacloprid exposure. The transcript level ofNlCYP4CE1was significantly increased by imidacloprid, but this effect was significantly weakened afterWolbachiawas cleared with tetracycline. This result suggests thatWolbachiaenhances the expression ofNlCYP4CE1to promote the detoxification metabolic response to imidacloprid stress. Understanding the effect of bacterial symbionts on gene expression in the host provides a new perspective on interactions between insecticides and their target insect pests, and highlights that subtoxic imidacloprid exposure may raise the risk of insecticide resistance by altering the structure of bacterial symbiont communities.

Automated summary

This study revealed that exposure of the brown planthopper to subtoxic levels of imidacloprid altered the structure of its bacterial symbiont community, with an increase in Wolbachia abundance. These symbionts enhanced the detoxification metabolic response of the planthopper to imidacloprid, highlighting the potential risk of insecticide resistance due to changes in bacterial symbiont communities caused by subtoxic imidacloprid exposure.