Resumen
Metarhizium anisopliae is a broad-spectrum entomopathogenic fungus with large-scale applications in pest control; however, its slow-killing action is a limiting factor. To enhance fungal virulence, we constructed transgenic M. anisopliae strains that expressed dsRNA targeting the chitin synthase gene A in the brown planthopper Nilaparvata lugens (NlCHSA). The transcription of NlCHSA was suppressed in N. lugens infected by transgenic M. anisopliae strains. Consequently, the cumulative mortality of N. lugens caused by those transgenic strains was increased by 34.7?40.0% on day 6 after inoculation, and their median lethal times (LT50) were about 50% compared to the wild-type strain. Our results demonstrate that dsRNA expression in M. anisopliae caused RNA silencing in the host insect after infection and hence greatly enhanced the fungal virulence, highlighting a new strategy for augmentation of fungal virulence against sucking pests.