Project description:As the phyllosphere is a resource-limited niche, microbes have evolved different survival strategies by collaborating or competing with other organisms. This leads to the establishment of network structures which are stabilised by so-called microbial hub organisms. An already identified hub in the Arabidopsis thaliana phyllosphere is the oomycete pathogen Albugo laibachii. From wild Arabidopsis plants with white rust symptoms we isolated the basidiomycete yeast Moesziomyces albugensis, which is closely related to plant pathogenic smut fungi. It suppresses the infection of A. laibachii in lab experiments and inhibits growth of several bacterial phyllosphere members. The transcriptomic response of M. albugensis to presence of A. laibachii and bacterial SynCom members was investigated by using RNA sequencing. Interestingly, several genes encoding secretory proteins, mostly glycoside hydrolases and peptidases, are particularly induced upon interaction with A. laibachii.