Abstract Detail

Genetics/Molecular Biology

Uehling, Jessie [1], Hameed, Khalid [2], Tschaplinski, Timothy [3], Gryganskyi, Andrii [2], Labbé, Jessy [3], Pelletier, Dale [3], Schaefer, Amy [4], Schadt, Christopher [3], Vilgalys, Rytas [5], Bonito, Gregory [6].

Genomic-based interaction inferences of the bacterial endosymbiont Glomeribacter sp. lineage with associated fungal hosts.

Recently joint efforts to understand Populus microbiome dynamics have yielded cultures of many beneficial fungi, including Mortierella elongata (Mortierellomycotina). This fast-growing, coenocytic fungus harbors a bacterial endosymbiont that has been placed phylogenetically within the Burkholderiaceae. We recently obtained the genome sequences of both M. elongata and its endosymbiont and our analyses indicate shared ancestry with Glomeribacter gigasporarum, an endosymbiont associated with the Glomeromycota genera Gigaspora and Scutellospora. The genome for Glomeribacter gigasporarum is also available and comparative analyses indicate that as a lineage, Glomeribacter share genomic attributes with other Eukaryote endosymbionts such as reduced genomes and mutations affecting specific metabolic processes. We have cleared several Mortierella elongata strains of Glomeribacter and observed notable fungal fitness costs associated with supporting the endosymbiont in particular conditions. Metabolomics and morphological analyses indicate cleared strains accumulate significantly more fatty acids than those harboring endosymbionts, leading us to hypothesize a trophic basis for the interaction. These host-endosymbiont interaction inferences are largely supported by genomic content analyses. Although the Glomeribacter lineage is present in both AM fungi and Zygomycetes, and the genomes are similar in many ways, there appear to be key differences in metabolic function and host interaction dynamics. Despite of the apparent fitness cost associated with endosymbiont occurrence, the mutual presence of these bacterial relatives in close fungal relatives suggests an ancient origin for the symbiosis. Specific roles of this endosymbiont to their fungal host and conditions under which the interaction may be beneficial or parasitic remain to be elucidated. Aspects of the interactions between Glomeribacter and its fungal hosts will be further discussed.

Related Links:
Vilgalys Lab website
Plant Microbe Interface

1 - Duke University, Program in Genetics & Genomics, 595 LaSalle Street, Box 103855 DUMC, Durham, NC, 27710, United States
2 - Duke University, Biology, 595 LaSalle Street, Box 103855 DUMC, Durham, NC, 27710, United States
3 - Oak Ridge National Laboratory, Plant Systems Biology, 1 Bethel Valley Rd, Oak Ridge, TN, 37830, United States
4 - University of Washington, Department of Microbiology, Box 357735, 1705 NE Pacific St, Seattle, WA, 98195, United States
5 - Duke University, Department Of Botany, Box 90338, Durham, NC, 27708-0338, USA
6 - Royal Bontical Gardens Melbourne, Private Bag 2000, Birdwood Avenue, South Yarra , Victoria , 3141, Australia

Keywords:
endosymbiosis
Mortierella
Glomeribacter
comparative genomics
metabolomics
transcriptomics.

Presentation Type: Offered Paper - Paper
Session: 4
Location: Auditorium/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 1:15 PM
Number: 4002
Abstract ID:161
Candidate for Awards:Graduate Student Oral Presentation Award