Abstract
In natural habitats, plants are not only challenged by pathogenic organisms, but also extensively colonized by commensal microbes. The network of interactions that these microbes establish with their host and amongst each other has been suggested to contribute to the immune responses of plants against pathogens. In wild Arabidopsis thaliana populations, the oomycete pathogen Albugo laibachii has been shown to play an influential role in structuring the microbial communities of the leaf surface, known as phyllosphere. In this study, we show that the epiphytic yeast Moesziomyces albugensis, a close relative of pathogenic smut fungi, plays an antagonistic role in the microbial phyllosphere of Arabidopsis thaliana. In particular, M. albugensis prevents infection of A. thaliana by A. laibachii. Through a combination of transcriptome analysis and reverse genetics we identified a gene encoding a putative GH25 hydrolase as the major effector of the microbial antagonism of M. albugensis. Our findings broaden the understanding of microbial interactions within the phyllosphere, provide insights into the evolution of epiphytic basidiomycete yeasts and pave the way for the development of novel biocontrol strategies.
Competing Interest Statement
The authors have declared no competing interest.
