Two Groups of Phytoplasmas from Japan Distinguished on the Basis of Amplification and Restriction Analysis of 16S rDNA

Abstract

Phytoplasmas (mycoplasmalike organisms, MLOs) associated with mitsuba (Japanese hone-wort) witches'-broom (JHW), garland chrysanthemum witches'-broom (GCW), eggplant dwarf (ED), tomato yellows (TY), marguerite yellows (MY), gentian witches'-broom (GW), and tsu-wabuki witches'-broom (TW) in Japan were investigated by polymerase chain reaction (PCR) amplification of DNA and restriction enzyme analysis of PCR products. The phytoplasmas could be separated into two groups, one containing strains JHW, GCW, ED, TY, and MY, and the other containing strains GW and TW, corresponding to two groups previously recognized on the basis of transmission by Macrosteles striifrons and Scleroracus flavopictus, respectively. The strains transmitted by M. striifrons were classified in 16S rRNA gene group 16SrI, which contains aster yellows and related phytoplasma strains. Strains GW and TW were classified in group 16SrIII, which contains phytoplasmas associated with peach X-disease, clover yellow edge, and related phytoplasmas. Digestion of amplified 16S rDNA with HpaII indicated that strains GW and TW were affiliated with subgroup 16SrIII-B, which contains clover yellow edge phytoplasma. All seven strains were distinguished from other phytoplasmas, including those associated with clover proliferation, ash yellows, elm yellows, and beet leafhopper-transmitted virescence in North America, and Malaysian periwinkle yellows and sweet potato witches'-broom in Asia.

Occurrence of rocket larkspur witches’ broom caused by “Candidatus Phytoplasma asteris” in Japan

“…Because OY and several 16Sr I-B group phytoplasma in Japan were reported to be transmitted by Macrosteles striifrons Anufriev (Okuda et al 1997), the transmissibility of RlWB phytoplasma by M. striifrons was also examined. About 100 nymphs of nonviruliferous M. striifrons in the second or the third instars fed on the young shoots of severely diseased C. ambigua for 24 h. After the acquisition access, about 50% of the nymphs had died, and the surviving nymphs were transferred and reared on healthy garland chrysanthemum plants.…”

Antiserum raised against gyrase A of Acholeplasma laidlawii reacts with phytoplasma proteins

“…Details of the original ¢eld-infected plants, vector relationships, and geographic origin were described previously [4]. Rice plants naturally infected with rice yellow dwarf (RYD) phytoplasma and healthy ones were collected at Kawachi, Tochigi Prefecture, Japan.…”

“…In the last decade, the phylogenic relationships among phytoplasmas and the phylogenic relationships between phytoplasmas and other prokaryotes have been established based on 16S rRNA sequences. These studies have classi¢ed the phytoplasmas into 14 groups [3] which are congruous with insect vector speci¢c-ity [4], and have shown that phytoplasmas are more closely related to acholeplasmas than any other mollicute [5]. On the other hand, very little is known about phytoplasma proteins, mainly because of the di¤culty in preparing phytoplasma-speci¢c proteins from infected plant or insect vector tissues.…”

Phylogenetic analysis of elongation factor Tu gene of phytoplasmas from Japan

“…Culture methods for phytoplasmas have never been established (McCoy et al 1989). Through the introduction of molecular methods in plant mycoplasmology, it has become possible to determine the phylogenetic and taxonomic relations among phytoplasmas and between phytoplasmas and other prokaryotes (Lee et al 1998Okuda et al 1997;Seemüller et al 1994;Weisberg et al 1989). …”

“…All samples, except paulownia witches' broom (PaW) strain, were maintained in Madagascar periwinkle [Catharanthus roseus (L.) G. Don] (Table 1) (Koike et al 1983;Okuda et al 1997). Paulownia plants (Paulownia tomentosa Thumb.)…”