title: "Candidatus Phytoplasma oryzae", a novel phytoplasma taxon associated with rice yellow dwarf disease.
abstract: In addition to rice yellow dwarf (RYD) phytoplasma, several phytoplasmas infect gramineous plants, including rice orange leaf, bermuda grass white leaf, brachiaria grass white leaf and sugarcane white leaf phytoplasmas. To investigate whether the RYD phytoplasma is a discrete, species-level taxon, several isolates of the aforementioned phytoplasmas were analysed using PCR-amplified 16S rDNA sequences. Two RYD isolates, RYD-J(T) and RYD-Th, were almost identical (99.2 %), but were distinct (similarities of 96.3-97.9 %) from other phytoplasma isolates of the RYD 16S-group. The notion that the RYD phytoplasma constitutes a unique taxon is also supported by its unique insect vector (Nephotettix sp.), its unique host plant in nature (rice) and its limited geographical distribution (Asia). In Southern blot analysis, chromosomal and extrachromosomal DNA probes of the RYD phytoplasma reportedly did not hybridize with those of closely related phytoplasmas. These properties of the RYD phytoplasma clearly indicate that it represents a novel taxon, 'Candidatus Phytoplasma oryzae'.
authors.affiliation: Laboratory of Plant Pathology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Jung
authors.forename: Toshimi
authors.initials: T
authors.lastname: Sawayanagi
authors.forename: Porntip
authors.initials: P
authors.lastname: Wongkaew
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kakizawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nishigawa
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Kenro
authors.initials: K
authors.lastname: Oshima
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Miyata
authors.forename: Masashi
authors.initials: M
authors.lastname: Ugaki
authors.forename: Tadaaki
authors.initials: T
authors.lastname: Hibi
authors.forename: Shigetou
authors.initials: S
authors.lastname: Namba
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D012275:Oryza / Q000382:microbiology; D010802:Phylogeny; D045582:Phytoplasma / Q000145:classification* / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology; D006109:Poaceae / Q000382:microbiology; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S