Insects defend against fungal infection by employing microRNAs to silence virulence-related genes
Yan Wang, Chunlai Cui, Guandong Wang, Yifei Li, Sibao Wang
Abstract
Significance The entomopathogenic fungus Beauveria bassiana can overcome insecticide resistance and represents a promising tool for controlling mosquitoes and other insect pests. Improvement of fungal efficacy requires better understanding of fungus–mosquito interactions. Here, we report on a new strategy of insect defense against fungal infection that employs translocation of miRNAs to silence virulence genes. Fungal infection activates production of Anopheles let-7 and miR-100 microRNAs (miRNAs). These miRNAs translocate into fungal hyphae to specifically silence the sec2p and C6TF fungal genes. Both genes are essential for fungal invasive growth and pathogenicity. Notably, virulence of a B. bassiana strain expressing both anti–let-7 and anti–miR-100 “sponge” RNAs is dramatically increased. This study may lead to new strategies for improved fungal-based vector control efficacy.