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

Jian-Hua Zhang,Ming Zhao,Yi-Jun Zhou,Yuan-Xue Yang,Qiu-Fang Xu

doi:10.3390/v13081576

Abstract

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.

Highlights

Key Laboratory of Food Quality and Safety of Jiangsu Province, State Key Laboratory Breeding Base, Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; Institute of Industrial Crops, Shandong Academy of Agricultural Sciences, Jinan 250100, China; Institute of Life Sciences, Jiangsu University, Zhenjiang 212013, China
All the four insecticide treatments significantly decreased the relative expression of rice black-streaked dwarf virus (RBSDV) S5-1, S6, S9-1, and S10 in L. striatellus (Figure 1A–D)
These results showed that these four insecticides inhibited virus abundance in L. striatellus

Summary

Introduction

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). Laodelphax striatellus can transmit rice stripe virus, rice black-streaked dwarf virus (RBSDV), maize rough dwarf virus, northern cereal mosaic virus, and barley yellow striate mosaic virus [3,4,5,6,7]. The outbreak of these viral diseases caused severe yield losses in rice-producing regions [4]. Little is known about the effect of insecticide on the virus transmitted by the planthoppers

Methods

Results

Conclusion