Detoxification of conifer antimicrobial defenses promotes entomopathogenic fungus infection of bark beetles

However, the role of spruce phenolics in this ecosystem remains unclear. We investigated the metabolism of phenolics by bark beetles and B. bassiana.

Bark beetles hydrolyze spruce phenolic glycosides, producing antifungal aglycons. In response, B. bassiana, isolated from bark beetles, counter-adapts to this defense using a methylation-glycosylation pathway. This pathway, involving UDP-glycosyltransferase and O-methyltransferase, converts toxic phenolic aglycones into non-toxic methyl-glycosylated derivatives, enhancing their stability against hydrolysis.