Helper bacteria halt and disarm mushroom pathogens by linearizing structurally diverse cyclolipopeptides

Abstract

Significance P. tolaasii is the causative agent of brown blotch disease in the common button mushroom Agaricus bisporus and responsible for tremendous losses in mushroom farms every year. The pathogen relies on two different cyclic lipopeptides during infection: the pore forming toxin tolaasin and the motility conferring biosurfactant pseudodesmin. In this study, we show how enzymes produced by helper bacteria of the genus Mycetocola provide protection to the mushroom via lipopeptide cleavage. Using bioactivity guided fractionation of the proteome, we could identify the key enzyme in toxin inactivation. Deciphering such protective interactions paves the way for the development of biocontrol agents for use in both agriculture and medicine.