Toru Iwanami

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The nucleotide sequences of genomic RNA1 (6795 nt) and RNA2 (5345 nt) of satsuma dwarf virus (SDV), a tentative member of the genus Nepovirus, were determined. The deduced genome organization of SDV showed similarities to the organization in como-, faba- and nepoviruses. There is extensive amino acid sequence similarity in the N-terminal regions of the(More)
Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide, and is caused by a phloem-limited fastidious prokaryotic alpha-proteobacterium that is yet to be cultured. In this study, a combination of traditional polymerase chain reaction (PCR) and real-time PCR targeting the putative DNA polymerase and 16S rDNA sequence of 'Candidatus(More)
The sequence of the 3'-terminal 2,201 nucleotides of RNA2 of citrus mosaic virus (CiMV) was determined. The sequence contains a long open reading frame (ORF) of 1989 nucleotides in the virus-sense strand and at 3' untranslated region of 212 nucleotides upstream of a poly(A) tail. The N-terminal amino acid sequence of the two coat proteins was determined by(More)
The sequences of the 3′-terminal 1306 and 2160 nucleotides of RNAs 1 and 2 of a virus serologically related to Satsuma dwarf virus (SDV) from Hyuganatsu (Citrus tamurana Hort. ex Tan.) were determined, respectively. We found that the partial RNA-dependent RNA polymerase region in RNA1 and the coat proteins (CPs) region in RNA2 of the virus tentatively named(More)
The genus Nepovirus (family Comoviridae) was known both for a good level of homogeneity and for the presence of atypical members. In particular, the atypical members of the genus differed by the number of capsid protein (CP) subunits. While typical nepoviruses have a single CP subunit with three structural domains, atypical nepoviruses have either three(More)
Satsuma dwarf virus (SDV) and two closely related viruses, Citrus mosaic (CiMV), and Naval orange infectious mottling (NIMV), seriously affect citrus varieties grown in Japan and East Asia. All three viruses have icosahedral particles built of two proteins encapsidating two single-stranded genomic RNAs. The natural mode of transmission of these SDV-like(More)
ABSTRACT Sequential polyacrylamide gel electrophoresis analyses showed many viroid-like RNAs in samples collected from citrus trees in Japan. Reverse transcription polymerase chain reaction and sequencing analyses of the amplified fragments verified that they were derived from variants of six citrus viroids, Citrus exocortis viroid (CEVd), Citrus bent leaf(More)
The aim of this study was to investigate the genetic diversity and relationships among 'Candidatus Liberibacter asiaticus' isolates from different hosts and distinct geographical areas in Southeast Asia. Genetic diversity among 'Ca. Liberibacter asiaticus' was estimated by sequencing four well-characterized DNA fragments: the 16S ribosomal DNA (rDNA) and(More)
Four highly polymorphic simple sequence repeat (SSR) loci were selected and used to differentiate 84 Japanese isolates of "Candidatus Liberibacter asiaticus." The Nei's measure of genetic diversity values for these four SSRs ranged from 0.60 to 0.86. The four SSR loci were also highly polymorphic in four isolates from Taiwan and 12 isolates from Indonesia.
Citrus greening disease is caused by "Candidatus Liberibacter spp.," including "Candidatus Liberibacter asiaticus (Las)." For detecting this disease, we designed new primers from the Las 16S rDNA and used a very small DNA template for PCR. More Las-infected tissues were detected with our primers than with the common primers.