title: 'Candidatus Moeniiplasma glomeromycotorum', an endobacterium of arbuscular mycorrhizal fungi.
abstract: Arbuscular mycorrhizal fungi (AMF, subphylum Glomeromycotina) are symbionts of most terrestrial plants. They commonly harbour endobacteria of a largely unknown biology, referred to as MRE (Mollicutes/mycoplasma-related endobacteria). Here, we propose to accommodate MRE in the novel genus 'Candidatus Moeniiplasma.' Phylogeny reconstructions based on the 16S rRNA gene sequences cluster 'Ca.Moeniiplasma' with representatives of the class Mollicutes, whereas phylogenies derived from amino acid sequences of 19 genes indicate that it is a discrete lineage sharing ancestry with the members of the family Mycoplasmataceae. Cells of 'Ca.Moeniiplasma' reside directly in the host cytoplasm and have not yet been cultivated. They are coccoid, ~500 nm in diameter, with an electron-dense layer outside the plasma membrane. However, the draft genomes of 'Ca.Moeniiplasma' suggest that this structure is not a Gram-positive cell wall. The evolution of 'Ca.Moeniiplasma' appears to be driven by an ultrarapid rate of mutation accumulation related to the loss of DNA repair mechanisms. Moreover, molecular evolution patterns suggest that, in addition to vertical transmission, 'Ca.Moeniiplasma' is able to transmit horizontally among distinct Glomeromycotina host lineages and exchange genes. On the basis of these unique lifestyle features, the new species 'Candidatus Moeniiplasma glomeromycotorum' is proposed.
authors.affiliation: Graduate Field of Microbiology, Cornell University, Ithaca, NY, USA.
authors.forename: Mizue
authors.initials: M
authors.lastname: Naito
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.|Present address: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Desirò
authors.affiliation: School of Integrative Plant Science, Plant Pathology & Plant-Microbe Biology, Cornell University, Ithaca, NY, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: González
authors.affiliation: School of Integrative Plant Science, Plant Pathology & Plant-Microbe Biology, Cornell University, Ithaca, NY, USA.|Present address: Guizhou Academy of Agricultural Sciences, Guizhou Institute of Plant Protection, Guiyang 550006, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Tao
authors.affiliation: Division of Plant & Soil Sciences, West Virginia University, Morgantown, WV, USA.
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Morton
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Bonfante
authors.affiliation: School of Integrative Plant Science, Plant Pathology & Plant-Microbe Biology, Cornell University, Ithaca, NY, USA.
authors.forename: Teresa E
authors.initials: TE
authors.lastname: Pawlowska
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D038821:Mycorrhizae; D010802:Phylogeny; D010944:Plants / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D008973:Tenericutes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S