Genome sequencing reveals origins of a unique bacterial endosymbiosis in the earliest lineages of terrestrial Fungi
J. UEHLING (1), F. Dietrich (1), K. Barry (2), I. Grigoriev (2), A. Kuo (2), R. Ohm (2), A. Lipzen (2), M. Nolan (2), K. LaButti (2), J. Labbé (3), G. Bonito (4), F. Martin (5), R. Vilgalys (1) (1) Duke University, U.S.A.; (2) US Department of Energy Joint Genome Institute, U.S.A.; (3) Oak Ridge National Laboratory, U.S.A.; (4) Michigan State University, U.S.A.; (5) Institut National de la Recherche Agronomique, France

Several research groups have recently investigated the ubiquity and dynamics of bacterial endosymbionts living inside of fungal cells. There are a few studies on fungal hosts belonging to Asco- and Basidiomycota, however, the best-studied examples of endosymbiosis in fungi are from plant-associated zygomycetes. Best studied in the Arbuscular Mycorrhizal (AM) fungi, these endosymbionts are thought to be obligate, long-term residents of the intracellular environment where they may contribute to both fungal and plant health, although the direct or indirect nature of these interactions remain has yet to be experimentally evaluated. We isolated a strain of Mortierella elongata AG77 (Zygomycota, Mucormycotina, Mortierellales) from the rhizopshere of Populus deltoides. We found that M. elongata AG77 harbors a strain of bacterium Candidatus Glomeribacter sp. (Burkholderiaceae), and we have assembled and annotated genomes for both the host fungus and its resident endosymbiont. The genome of C. Glomeribacter sp. is similar to other publicly available genomes, but also has unique features potentially suggesting distinct functionality. In an attempt to understand the nature of the interaction between fungal host M. elongata and endosymbiont C. Glomeribacter sp. we used an antibiotic treatment to create a strain cleared of endosymbiont populations for comparative studies. Here we present comparative genomics, metabolomics, volatomics and physiological data on with and without obligate endosymbiont C. Glomeribacter sp. The following questions were addressed through this work: Does endosymbiont presence affect fungal host functioning? Do host-endosymbiont dynamics of Mortierella-Glomeribacter differ from those of the obligate plant associated AM fungus Gigaspora-Glomeribacter?


Abstract Number: P2-63
Session Type: Poster