Toru Iwanami

Tokyo University of Agriculture

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Mitsuru Okuda

National Agriculture and Food Research Organization

Takashi Fujikawa

National Agriculture and Food Research Organization

Kenta Tomimura

National Agriculture and Food Research Organization

Shin-ichi Miyata

Komatsu (Japan)

Siti Subandiyah

Universitas Gadjah Mada

Ade Rosmana

Hasanuddin University

Alexander V. Karasev

University of Idaho

Nami Uechi

National Agriculture and Food Research Organization

Asman Asman

Tokyo University of Agriculture

Hiroshi Katoh

Takasaki University of Health and Welfare

Cooperative Institutions

Institute of Fruit Tree and Tea Science

National Agriculture and Food Research Organization

The University of Tokyo

Kyushu Okinawa Agricultural Research Center

University of Florida

Tokyo University of Agriculture

Agricultural Research Center

United States Department of Agriculture

Kyoto University

Shimizu (Japan)

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Differences in the rate of detecting low-level Candidatus Liberibacter asiaticus infection in spontaneously infected samples among DNA amplification methods.

Kyushu Plant Protection Research (2009)

奥田充 Shinji Kawano Tetsuya Takushi Toru Iwanami

Polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and quantitative PCR (qPCR) were used to detect low-level Candidatus Liberibacter asiaticus infection in citrus trees, and their results were compared. Sample DNA was prepared from the developing shoots of Citrus depressa and Citrus tankan that were spontaneously infected with Ca. L. asiaticus. The concentrations of the homologous region of the tufB gene of Ca. L. asiaticus were estimated by qPCR analysis using serially diluted plasmid DNA containing the tufB gene region as a calibration standard. All DNA samples from which the specific amplification product was detected by PCR also gave positive results in the LAMP analysis, and qPCR gave positive results for all samples that were positive in the LAMP analysis. Therefore, we concluded that qPCR is the most sensitive method for detecting low-level Ca. L. asiaticus infection.

10.4241/kyubyochu.55.62

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Citations (3)

Unique Features of a Japanese ‘Candidatus Liberibacter asiaticus’ Strain Revealed by Whole Genome Sequencing

PLoS ONE (2014)

Hiroshi Katoh Shin-ichi Miyata Hiromitsu Inoue Toru Iwanami

Citrus greening (huanglongbing) is the most destructive disease of citrus worldwide. It is spread by citrus psyllids and is associated with phloem-limited bacteria of three species of α-Proteobacteria, namely, 'Candidatus Liberibacter asiaticus', 'Ca. L. americanus', and 'Ca. L. africanus'. Recent findings suggested that some Japanese strains lack the bacteriophage-type DNA polymerase region (DNA pol), in contrast to the Floridian psy62 strain. The whole genome sequence of the pol-negative 'Ca. L. asiaticus' Japanese isolate Ishi-1 was determined by metagenomic analysis of DNA extracted from 'Ca. L. asiaticus'-infected psyllids and leaf midribs. The 1.19-Mb genome has an average 36.32% GC content. Annotation revealed 13 operons encoding rRNA and 44 tRNA genes, but no typical bacterial pathogenesis-related genes were located within the genome, similar to the Floridian psy62 and Chinese gxpsy. In contrast to other 'Ca. L. asiaticus' strains, the genome of the Japanese Ishi-1 strain lacks a prophage-related region.

Prophage

GC-content

Genome size

Strain (injury)

10.1371/journal.pone.0106109

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Citations (61)

Sequence homogeneity of the ψserA-trmU-tufB-secE-nusG-rplKAJL-rpoB gene cluster and the flanking regions of ‘Candidatus Liberibacter asiaticus’ isolates around Okinawa Main Island in Japan

Journal of General Plant Pathology (2010)

Noriko Furuya Keiichiro Matsukura Kenta Tomimura Mitsuru Okuda Shin-ichi Miyata

rpoB

Mega-

10.1007/s10327-010-0223-8

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Citations (17)

Natural Infection of Murraya paniculata and Murraya sumatrana with CLas in Java

Plant Disease (2024)

Ayu Lestiyani Tri Joko Paul Holford G. A. C. Beattie Nerida J. Donovan

The phloem-limited bacterium '

Murraya

10.1094/pdis-12-23-2593-re

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Major Citrus Viruses in Japan

Japan Agricultural Research Quarterly JARQ (2023)

Toru Iwanami

Citrus species grown in Japan are affected by three major viruses: satsuma dwarf virus (SDV), citrus tatter leaf virus (CTLV, apple stem grooving virus), and citrus tristeza virus (CTV). SDV has spread to other countries, such as China, Korea, and Turkey, apparently through unchecked budwoods and nursery trees; it is natural to assume that some of these contaminated plants harbored CTLV and CTV as well. Thus, citrus viruses in Japan are not only a domestic problem, they are also transboundary threats to agricultural production. This article reviews the occurrence and history of SDV, CTLV, and CTV in Japan as well as recent research developments in Japan and other countries.

Citrus tristeza virus

10.6090/jarq.57.99

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Citations (2)

Changes in Variable Number of Tandem Repeats in ‘Candidatus Liberibacter asiaticus’ through Insect Transmission

PLoS ONE (2015)

Hiroshi Katoh Hiromitsu Inoue Toru Iwanami

Citrus greening (huanglongbing) is the most destructive citrus disease worldwide. The disease is associated with three species of 'Candidatus Liberibacter' among which 'Ca. Liberibacter asiaticus' has the widest distribution. 'Ca. L. asiaticus' is commonly transmitted by a phloem-feeding insect vector, the Asian citrus psyllid Diaphorina citri. A previous study showed that isolates of 'Ca. L. asiaticus' were clearly differentiated by variable number of tandem repeat (VNTR) profiles at four loci in the genome. In this study, the VNTR analysis was further validated by assessing the stability of these repeats after multiplication of the pathogen upon host-to-host transmission using a 'Ca. L. asiaticus' strain from Japan. The results showed that some tandem repeats showed detectable changes after insect transmission. To our knowledge, this is the first report to demonstrate that the repeat numbers VNTR 002 and 077 of 'Ca. L. asiaticus' change through psyllid transmission. VNTRs in the recipient plant were apparently unrelated to the growing phase of the vector. In contrast, changes in the number of tandem repeats increased with longer acquisition and inoculation access periods, whereas changes were not observed through psyllid transmission after relatively short acquisition and inoculation access periods, up to 20 and 19 days, respectively.

Diaphorina citri

10.1371/journal.pone.0138699

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Citations (10)

Genetic diversity and a heterogeneous population of Citrus mosaic virus within a single citrus tree

Journal of General Plant Pathology (2007)

T. Ito Tsutae Ito Hiroshi Shiotani Toru Iwanami Katsumi Ozaki

Mosaic virus

10.1007/s10327-006-0329-1

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Citations (9)

Evaluation of the potential of thirty two weed species as infection sources of Impatiens necrotic spot virus.