title: Detection of Magnaporthe oryzae chrysovirus 1 in Japan and establishment of a rapid, sensitive and direct diagnostic method based on reverse transcription loop-mediated isothermal amplification.
abstract: Magnaporthe oryzae chrysovirus 1 (MoCV1) is a mycovirus with a dsRNA genome that infects the rice blast fungus Magnaporthe oryzae and impairs its growth. To date, MoCV1 has only been found in Vietnamese isolates of M. oryzae, and the distribution of this virus in M. oryzae isolates from other parts of the world remains unknown. In this study, using a one-step reverse transcription PCR (RT-PCR) assay, we detected a MoCV1-related virus in M. oryzae in Japan (named MoCV1-AK) whose sequence shares considerable similarity with that of the MoCV1 Vietnamese isolate. To establish a system for a comprehensive survey of MoCV1 infection in the field, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for direct detection of the virus. The sensitivity of the RT-LAMP assay was at least as high as that of the one-step RT-PCR assay. In addition, we detected MoCV1-AK in M. oryzae-infected oatmeal agar plates and lesions on rice leaves using the RT-LAMP assay without dsRNA extraction, by simple sampling with a toothpick. Preliminary screening of MoCV1 in Japanese M. oryzae isolates indicated that MoCV1 is currently distributed in rice fields in Japan. Our results provide a first example of the application of RT-LAMP for the detection of mycoviruses, which will accelerate surveys for mycovirus infection.
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Komatsu
authors.affiliation: Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Syun-Ichi
authors.initials: S
authors.lastname: Urayama
authors.affiliation: Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Katoh
authors.affiliation: Laboratory of Plant Protection, Faculty of Bioresorce Sciences, Akita Prefectural University, Akita, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Fuji
authors.affiliation: Laboratory of Plant Pathology, Faculty of Agriculture, Yamagata University, Yamagata, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Hase
authors.affiliation: Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Fukuhara
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arie
authors.affiliation: Laboratory of Plant Pathology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Teraoka
authors.affiliation: Laboratory of Molecular and Cellular Biology, Graduate School of Agriculture, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan. hmori714@cc.tuat.ac.jp.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Moriyama
mesh_terms: D001483:Base Sequence; D016000:Cluster Analysis; D000067148:Fungal Viruses / Q000235:genetics / Q000302:isolation & purification*; D007564:Japan; D020082:Magnaporthe / Q000254:growth & development / Q000821:virology*; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012275:Oryza / Q000382:microbiology; D010802:Phylogeny; D012328:RNA Viruses / Q000235:genetics / Q000302:isolation & purification*; D012367:RNA, Viral / Q000235:genetics; D048348:Reverse Transcription; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013696:Temperature; D013997:Time Factors
chemical_list: D012367:RNA, Viral