title: Contribution of folate biosynthesis to Ralstonia solanacearum proliferation in intercellular spaces.
abstract: The vigorous proliferation of Ralstonia solanacearum OE1-1 in host intercellular spaces after the invasion of host plants is necessary for the virulence of this bacterium. A folate auxotroph, RM, in which a mini-Tn5 transposon was inserted into pabB encoding para-aminobenzoate synthase component I, lost its ability to vigorously proliferate in intercellular spaces along with its systemic infectivity and virulence after inoculation into roots and infiltration into leaves of tobacco plants. Complementation of RM with the pabB gene allowed the mutant to multiply in intercellular spaces and to cause disease. In tobacco plants that were pretreated with folate, RM was able to vigorously proliferate in the intercellular spaces and cause disease. Interestingly, when it was inoculated through cut stems, the mutant multiplied in the plants and was virulent. Moreover, the mutant multiplied well in stem fluids but not in intercellular fluids, suggesting that the folate concentration within intercellular spaces may be a limiting factor for bacterial proliferation. Therefore, folate biosynthesis contributes to the vigorous proliferation of bacteria in intercellular spaces and leads to systemic infectivity resulting in virulence.
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, 200 Monobe, Nankoku, Kochi 783-8502, Japan.
authors.forename: Rena
authors.initials: R
authors.lastname: Shinohara
authors.forename: Ayami
authors.initials: A
authors.lastname: Kanda
authors.forename: Kouhei
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Akinori
authors.initials: A
authors.lastname: Kiba
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Hikichi
mesh_terms: D004251:DNA Transposable Elements; D005110:Extracellular Space / Q000382:microbiology*; D005492:Folic Acid / Q000096:biosynthesis* / Q000494:pharmacology; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000187:drug effects / Q000382:microbiology; D018517:Plant Roots / Q000187:drug effects / Q000382:microbiology; D043368:Ralstonia solanacearum / Q000235:genetics / Q000254:growth & development* / Q000472:pathogenicity*; D017422:Sequence Analysis, DNA; D014026:Nicotiana / Q000187:drug effects / Q000382:microbiology*; D014774:Virulence
chemical_list: D004251:DNA Transposable Elements; D005492:Folic Acid