Transcriptomics Reveals the Killing Mechanism by Which Entomopathogenic Fungi Manipulate the RNA Expression Profiles of Termites and Provides Inspiration for Green Pest Management

As
chemical pesticides have caused serious environmental pollution,
fungus-based biological control has become a developing alternative
to chemical control. Here, we aimed to determine the molecular mechanism
underlying how Metarhizium anisopliae facilitated invasive infection. We found that the fungus increased
its virulence by downregulating glutathione S-transferase (GST) and superoxide dismutase (SOD) throughout termite bodies. Among 13 fungus-induced
microRNAs throughout termite bodies, miR-7885-5p and miR-252b upregulation
significantly downregulated several mRNAs in response to toxic substances
to increase the fungal virulence [e.g., phosphoenolpyruvate
carboxykinase (GTP) and heat shock
protein homologue SSE1]. In addition, nanodelivered small
interfering RNA of GST and SOD and
miR-7885-5p and miR-252b mimics increased the virulence of the fungus.
These findings provide new insights into the killing mechanism of
entomopathogens and their utilization of the host miRNA machinery
to reduce host defenses, laying the groundwork to enhance virulence
of biocontrol agents for green pest management.