Vertical Transmission of Endobacteria in the Arbuscular Mycorrhizal Fungus Gigaspora margarita through Generation of Vegetative Spores
AUTOR(ES)
Bianciotto, V.
FONTE
American Society for Microbiology
RESUMO
Arbuscular mycorrhizal (AM) fungi living in symbiotic association with the roots of vascular plants have also been shown to host endocellular rod-shaped bacteria. Based on their ribosomal sequences, these endobacteria have recently been identified as a new taxon, Candidatus Glomeribacter gigasporarum. In order to investigate the cytoplasmic stability of the endobacteria in their fungal host and their transmission during AM fungal reproduction (asexual), a system based on transformed carrot roots and single-spore inocula of Gigaspora margarita was used. Under these in vitro sterile conditions, with no risk of horizontal contamination, the propagation of endobacteria could be monitored, and it was shown, by using primers designed for both 16S and 23S ribosomal DNAs, to occur through several vegetative spore generations (SG0 to SG4). A method of confocal microscopy for quantifying the density of endobacteria in spore cytoplasm was designed and applied; endobacteria were consistently found in all of the spore generations, although their number rapidly decreased from SG0 to SG4. The study demonstrates that a vertical transmission of endobacteria takes place through the fungal vegetative generations (sporulation) of an AM fungus, indicating that active bacterial proliferation occurs in the coenocytic mycelium of the fungus, and suggests that these bacteria are obligate endocellular components of their AM fungal host.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=427789Documentos Relacionados
- Polyphosphates in Intraradical and Extraradical Hyphae of an Arbuscular Mycorrhizal Fungus, Gigaspora margarita
- Invasion of Spores of the Arbuscular Mycorrhizal Fungus Gigaspora decipiens by Burkholderia spp.
- Identification of a Putative P-Transporter Operon in the Genome of a Burkholderia Strain Living inside the Arbuscular Mycorrhizal Fungus Gigaspora margarita
- Isolation, Free-Living Capacities, and Genome Structure of “Candidatus Glomeribacter gigasporarum,” the Endocellular Bacterium of the Mycorrhizal Fungus Gigaspora margarita
- The Mycorrhizal Fungus Gigaspora margarita Possesses a CuZn Superoxide Dismutase That Is Up-Regulated during Symbiosis with Legume Hosts1