Ergot Alkaloid-Producing Aspergillus Species with Entomopathogenic Capabilities

Presenter(s)

Abigail Jones

Abstract or Description

Ergot alkaloids such as lysergic acid alpha-hydroxyethylamide (LAH) produced by certain fungi are important ecologically and pharmaceutically. We recently discovered three species of Aspergillus that produce LAH. Since the same alkaloid accumulates in the insect pathogenic fungus Metarhizium brunneum, we tested if the Aspergillus species were capable of infecting insects. Aspergillus leporis and A. hancockii killed nearly all injected larvae of the model insect Galleria mellonella within the first five days, while larvae injected with A. homomorphus survived well. Aspergillus leporis and A. hancockii emerged from and sporulated on dead insects. Aspergillus leporis and A. hancockii also infected insects that were placed on sporulating cultures, but the rate of infection was lower and more variable. The data indicate A. leporis and A. hancockii have the ability to act as insect pathogens but that A. homomorphus does not. To test if the ergot alkaloid LAH contributes to pathogenesis, the early-pathway gene easD was knocked out in A. leporis using CRISPR technology and LAH was eliminated. Larvae injected with spores of the LAH-deficient strain died at a slower rate. These observations indicate that A. leporis and A. hancockii have pathogenic potential and that LAH contributes to their virulence.