Expression of host-specific Lysyloxidase double-stranded RNA in Metarhizhium anisopliae enhanced virulence against the rice pest Sogatella furcifera.

Abstract

BACKGROUND Entomopathogenic fungi show great potential as biological control agents for managing insect pests. However, host defenses have limited the effectiveness of these fungi in practice. Utilizing genetic engineering-based technology could be a promising strategy to enhance the killing efficiency of these fungi against insect pests. RESULTS In this study, we identified a gene Lysyloxidase (SfLox) in Sogatella furcifera, with a Scavenger receptor Cys-rich domain that significantly responds to infection by the fungus Metarhizhium anisopliae. RNA interference (RNAi) targeting this gene reduced the survival of the host S. furcifera when infected with M. anisopliae. Additionally, introducing double-stranded RNA (dsRNA) targeting SfLox into M. anisopliae, resulting in the genetically engineered strain M. anisopliae-Sfox-RNAi, eventually enhanced its virulence against the rice pest S. furcifera. Further research demonstrated that genetically engineered M. anisopliae promoted the formation of hyphal bodies in the host's body compared to the wild strain, while also disrupting the host's immune responses. CONCLUSIONS Expressing host Lysyloxidase dsRNA in M. anisopliae improved its virulence against insect hosts and facilitated its proliferation within the host's body. This study proposes that the combination of dsRNA with entomopathogenic fungi through genetic engineering could serve as an effective approach for controlling insect pests. This offers a promising opportunity to enhance pest management strategies. © 2025 Society of Chemical Industry.