Updated on 2024/02/02

写真a

 
HYOUDOU Kiwamu
 
Organization
Institute of Plant Science and Resources Associate Professor
Position
Associate Professor
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Degree

  • 博士(農学) ( 京都大学 )

Education

  • Kyoto University   農学研究科   応用生物科学専攻

    2011.4 - 2014.3

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    Notes: 博士課程

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  • 京都大学大学院   農学研究科   応用生物科学専攻

    2009.4 - 2011.3

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    Notes: 修士課程

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  • Kyoto University   農学部   資源生物科学科

    2005.4 - 2009.3

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Research History

  • Okayama University   Institute of Plant Science and Resources   Associate Professor

    2020.4

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  • Okayama University   Institute of Plant Science and Resources   Assistant Professor

    2015.4 - 2020.3

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Papers

  • Discovery and Genome Characterization of a Closterovirus from Wheat Plants with Yellowing Leaf Symptoms in Japan

    Hideki Kondo, Hitomi Sugahara, Miki Fujita, Kiwamu Hyodo, Ida Bagus Andika, Hiroshi Hisano, Nobuhiro Suzuki

    Pathogens   12 ( 3 )   358 - 358   2023.2

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    Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Many aphid-borne viruses are important pathogens that affect wheat crops worldwide. An aphid-transmitted closterovirus named wheat yellow leaf virus (WYLV) was found to have infected wheat plants in Japan in the 1970s; however, since then, its viral genome sequence and occurrence in the field have not been investigated. We observed yellowing leaves in the 2018/2019 winter wheat-growing season in an experimental field in Japan where WYLV was detected five decades ago. A virome analysis of those yellow leaf samples lead to the discovery of a closterovirus together with a luteovirus (barley yellow dwarf virus PAV variant IIIa). The complete genomic sequence of this closterovirus, named wheat closterovirus 1 isolate WL19a (WhCV1-WL19a), consisted of 15,452 nucleotides harboring nine open reading frames. Additionally, we identified another WhCV1 isolate, WL20, in a wheat sample from the winter wheat-growing season of 2019/2020. A transmission test indicated that WhCV1-WL20 was able to form typical filamentous particles and transmissible by oat bird-cherry aphid (Rhopalosiphum pad). Sequence and phylogenetic analyses showed that WhCV1 was distantly related to members of the genus Closterovirus (family Closteroviridae), suggesting that the virus represents a novel species in the genus. Furthermore, the characterization of WhCV1-WL19a-derived small RNAs using high-throughput sequencing revealed highly abundant 22-nt-class small RNAs potentially derived from the 3′-terminal end of the WhCV1 negative-strand genomic RNA, indicating that this terminal end of the WhCV1 genome is likely particularly targeted for the synthesis of viral small RNAs in wheat plants. Our results provide further knowledge on closterovirus diversity and pathogenicity and suggest that the impact of WhCV1 on wheat production warrants further investigations.

    DOI: 10.3390/pathogens12030358

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  • Identification and characterization of host factors involved in plant RNA virus replication

    Kiwamu Hyodo

    JOURNAL OF GENERAL PLANT PATHOLOGY   87 ( 6 )   415 - 417   2021.11

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:SPRINGER JAPAN KK  

    DOI: 10.1007/s10327-021-01022-9

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  • Identification of an RNA silencing suppressor encoded by a symptomless fungal hypovirus, Cryphonectria hypovirus 4

    Annisa Aulia, Kiwamu Hyodo, Sakae Hisano, Hideki Kondo, Bradley I. Hillman, Nobuhiro Suzuki

    Biology   10 ( 2 )   1 - 16   2021.2

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    Previously, we have reported the ability of a symptomless hypovirus Cryphonectria hypovirus 4 (CHV4) of the chestnut blight fungus to facilitate stable infection by a co-infecting mycoreovirus 2 (MyRV2)—likely through the inhibitory effect of CHV4 on RNA silencing (Aulia et al., Virology, 2019). In this study, the N-terminal portion of the CHV4 polyprotein, termed p24, is identified as an autocatalytic protease capable of suppressing host antiviral RNA silencing. Using a bacterial expression system, CHV4 p24 is shown to cleave autocatalytically at the di-glycine peptide (Gly214-Gly215) of the polyprotein through its protease activity. Transgenic expression of CHV4 p24 in Cryphonectria parasitica suppresses the induction of one of the key genes of the antiviral RNA silencing, dicer-like 2, and stabilizes the infection of RNA silencing-susceptible virus MyRV2. This study shows functional similarity between CHV4 p24 and its homolog p29, encoded by the symptomatic prototype hypovirus CHV1.

    DOI: 10.3390/biology10020100

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  • Identification of a Novel Quinvirus in the Family Betaflexiviridae That Infects Winter Wheat. International journal

    Hideki Kondo, Naoto Yoshida, Miki Fujita, Kazuyuki Maruyama, Kiwamu Hyodo, Hiroshi Hisano, Tetsuo Tamada, Ida Bagus Andika, Nobuhiro Suzuki

    Frontiers in microbiology   12   715545 - 715545   2021

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    Yellow mosaic disease in winter wheat is usually attributed to the infection by bymoviruses or furoviruses; however, there is still limited information on whether other viral agents are also associated with this disease. To investigate the wheat viromes associated with yellow mosaic disease, we carried out de novo RNA sequencing (RNA-seq) analyses of symptomatic and asymptomatic wheat-leaf samples obtained from a field in Hokkaido, Japan, in 2018 and 2019. The analyses revealed the infection by a novel betaflexivirus, which tentatively named wheat virus Q (WVQ), together with wheat yellow mosaic virus (WYMV, a bymovirus) and northern cereal mosaic virus (a cytorhabdovirus). Basic local alignment search tool (BLAST) analyses showed that the WVQ strains (of which there are at least three) were related to the members of the genus Foveavirus in the subfamily Quinvirinae (family Betaflexiviridae). In the phylogenetic tree, they form a clade distant from that of the foveaviruses, suggesting that WVQ is a member of a novel genus in the Quinvirinae. Laboratory tests confirmed that WVQ, like WYMV, is potentially transmitted through the soil to wheat plants. WVQ was also found to infect rye plants grown in the same field. Moreover, WVQ-derived small interfering RNAs accumulated in the infected wheat plants, indicating that WVQ infection induces antiviral RNA silencing responses. Given its common coexistence with WYMV, the impact of WVQ infection on yellow mosaic disease in the field warrants detailed investigation.

    DOI: 10.3389/fmicb.2021.715545

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  • Virome Analysis of Aphid Populations That Infest the Barley Field: The Discovery of Two Novel Groups of Nege/Kita-Like Viruses and Other Novel RNA Viruses. Reviewed International journal

    Hideki Kondo, Miki Fujita, Hiroshi Hisano, Kiwamu Hyodo, Ida Bagus Andika, Nobuhiro Suzuki

    Frontiers in microbiology   11   509 - 509   2020

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    Aphids (order Hemiptera) are important insect pests of crops and are also vectors of many plant viruses. However, little is known about aphid-infecting viruses, particularly their diversity and relationship to plant viruses. To investigate the aphid viromes, we performed deep sequencing analyses of the aphid transcriptomes from infested barley plants in a field in Japan. We discovered virus-like sequences related to nege/kita-, flavi-, tombus-, phenui-, mononega-, narna-, chryso-, partiti-, and luteoviruses. Using RT-PCR and sequence analyses, we determined almost complete sequences of seven nege/kitavirus-like virus genomes; one of which was a variant of the Wuhan house centipede virus (WHCV-1). The other six seem to belong to four novel viruses distantly related to Wuhan insect virus 9 (WhIV-9) or Hubei nege-like virus 4 (HVLV-4). We designated the four viruses as barley aphid RNA virus 1 to 4 (BARV-1 to -4). Moreover, some nege/kitavirus-like sequences were found by searches on the transcriptome shotgun assembly (TSA) libraries of arthropods and plants. Phylogenetic analyses showed that BARV-1 forms a clade with WHCV-1 and HVLV-4, whereas BARV-2 to -4 clustered with WhIV-9 and an aphid virus, Aphis glycines virus 3. Both virus groups (tentatively designated as Centivirus and Aphiglyvirus, respectively), together with arthropod virus-like TSAs, fill the phylogenetic gaps between the negeviruses and kitaviruses lineages. We also characterized the flavi/jingmen-like and tombus-like virus sequences as well as other RNA viruses, including six putative novel viruses, designated as barley aphid RNA viruses 5 to 10. Interestingly, we also discovered that some aphid-associated viruses, including nege/kita-like viruses, were present in different aphid species, raising a speculation that these viruses might be distributed across different aphid species with plants being the reservoirs. This study provides novel information on the diversity and spread of nege/kitavirus-related viruses and other RNA viruses that are associated with aphids.

    DOI: 10.3389/fmicb.2020.00509

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  • Hijacking of host cellular components as proviral factors by plant-infecting viruses

    Kiwamu Hyodo, Tetsuro Okuno

    Advances in Virus Research   37 - 86   2020

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    Publishing type:Part of collection (book)   Publisher:Elsevier  

    DOI: 10.1016/bs.aivir.2020.04.002

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  • Diverse Partitiviruses From the Phytopathogenic Fungus, Rosellinia necatrix. International journal

    Paul Telengech, Sakae Hisano, Cyrus Mugambi, Kiwamu Hyodo, Juan Manuel Arjona-López, Carlos José López-Herrera, Satoko Kanematsu, Hideki Kondo, Nobuhiro Suzuki

    Frontiers in microbiology   11   1064 - 1064   2020

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    Partitiviruses (dsRNA viruses, family Partitiviridae) are ubiquitously detected in plants and fungi. Although previous surveys suggested their omnipresence in the white root rot fungus, Rosellinia necatrix, only a few of them have been molecularly and biologically characterized thus far. We report the characterization of a total of 20 partitiviruses from 16 R. necatrix strains belonging to 15 new species, for which "Rosellinia necatrix partitivirus 11-Rosellinia necatrix partitivirus 25" were proposed, and 5 previously reported species. The newly identified partitiviruses have been taxonomically placed in two genera, Alphapartitivirus, and Betapartitivirus. Some partitiviruses were transfected into reference strains of the natural host, R. necatrix, and an experimental host, Cryphonectria parasitica, using purified virions. A comparative analysis of resultant transfectants revealed interesting differences and similarities between the RNA accumulation and symptom induction patterns of R. necatrix and C. parasitica. Other interesting findings include the identification of a probable reassortment event and a quintuple partitivirus infection of a single fungal strain. These combined results provide a foundation for further studies aimed at elucidating mechanisms that underly the differences observed.

    DOI: 10.3389/fmicb.2020.01064

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  • Two novel fungal negative-strand RNA viruses related to mymonaviruses and phenuiviruses in the shiitake mushroom (Lentinula edodes). Reviewed

    Lin YH, Fujita M, Chiba S, Hyodo K, Andika IB, Suzuki N, Kondo H

    Virology   533   125 - 136   2019.7

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    There is still limited information on the diversity of (−)ssRNA viruses that infect fungi. Here, we have discovered two novel (−)ssRNA mycoviruses in the shiitake mushroom (Lentinula edodes). The first virus has a monopartite RNA genome and relates to that of mymonaviruses (Mononegavirales), especially to Hubei rhabdo-like virus 4 from arthropods and thus designated as Lentinula edodes negative-strand RNA virus 1. The second virus has a putative bipartite RNA genome and is related to the recently discovered bipartite or tripartite phenui-like viruses (Bunyavirales) associated with plants and ticks, and designated as Lentinula edodes negative-strand RNA virus 2 (LeNSRV2). LeNSRV2 is likely the first segmented (−)ssRNA virus known to infect fungi. Its smaller RNA segment encodes a putative nucleocapsid and a plant MP-like protein using a potential ambisense coding strategy. These findings enhance our understanding of the diversity, evolution and spread of (−)ssRNA viruses in fungi.

    DOI: 10.1016/j.virol.2019.05.008

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  • Hijacking a host scaffold protein, RACK1, for replication of a plant RNA virus. Reviewed

    Hyodo K, Suzuki N, Okuno T

    The New phytologist   221 ( 2 )   935 - 945   2019.1

  • The photosystem II repair cycle requires FtsH turnover through the EngA GTPase. Reviewed

    Kato Y, Hyodo K, Sakamoto W

    Plant physiology   178 ( 2 )   596 - 611   2018.8

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    Publishing type:Research paper (scientific journal)   Publisher:American Society of Plant Biologists (ASPB)  

    DOI: 10.1104/pp.18.00652

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  • Integration of danger peptide signals with herbivore-associated molecular pattern signaling amplifies anti-herbivore defense responses in rice. Reviewed International journal

    Tomonori Shinya, Shigetaka Yasuda, Kiwamu Hyodo, Rena Tani, Yuko Hojo, Yuka Fujiwara, Kei Hiruma, Takuma Ishizaki, Yasunari Fujita, Yusuke Saijo, Ivan Galis

    The Plant journal : for cell and molecular biology   94 ( 4 )   626 - 637   2018.5

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    Plant defense against herbivores is modulated by herbivore-associated molecular patterns (HAMPs) from oral secretions (OS) and/or saliva of insects. Furthermore, feeding wounds initiate plant self-damage responses modulated by danger-associated molecular patterns (DAMPs) such as immune defense-promoting plant elicitor peptides (Peps). While temporal and spatial co-existence of both patterns during herbivory implies a possibility of their close interaction, the molecular mechanisms remain undetermined. Here we report that exogenous application of rice (Oryza sativa) peptides (OsPeps) can elicit multiple defense responses in rice cell cultures. Specific activation of OsPROPEP3 gene transcripts in rice leaves by wounding and OS treatments further suggests a possible involvement of the OsPep3 peptide in rice-herbivore interactions. Correspondingly, we found that simultaneous application of OsPep3 and Mythimna loreyi OS significantly amplifies an array of defense responses in rice cells, including mitogen-activated protein kinase activation, and generation of defense-related hormones and metabolites. The induction of OsPROPEP3/4 by OsPep3 points to a positive auto-feedback loop in OsPep signaling which may contribute to additional enhancement of defense signal(s). Finally, the overexpression of the OsPep receptor OsPEPR1 increases the sensitivity of rice plants not only to the cognate OsPeps but also to OS signals. Our findings collectively suggest that HAMP-DAMP signal integration provides a critical step in the amplification of defense signaling in plants.

    DOI: 10.1111/tpj.13883

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  • Dual function of a cis-acting RNA element that acts as a replication enhancer and a translation repressor in a plant positive-stranded RNA virus Reviewed

    Kiwamu Hyodo, Hikari Nagai, Tetsuro Okuno

    VIROLOGY   512   74 - 82   2017.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    The genome of red clover necrotic mosaic virus is divided into two positive-stranded RNA molecules of RNA1 and RNA2, which have no 5' cap structure and no 3' poly(A) tail. Previously, we showed that any mutations in the cis-acting RNA replication elements of RNA2 abolished its cap-independent translational activity, suggesting a strong link between RNA replication and translation. Here, we investigated the functions of the 5' untranslated region (UTR) of RNA2 and revealed that the basal stem-structure (5'BS) predicted in the 5' UTR is essential for robust RNA replication. Interestingly, RNA2 mutants with substitution or deletion in the right side of the 5'BS showed strong translational activity, despite their impaired replication competency. Furthermore, nucleotide sequences other than the 5'BS of the 5' UTR were essential to facilitate the replication-associated translation. Overall, these cis-acting RNA elements seem to coordinately regulate the balance between RNA replication and replication-associated translation.

    DOI: 10.1016/j.virol.2017.09.008

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  • Requirement for eukaryotic translation initiation factors in cap-independent translation differs between bipartite genomic RNAs of red clover necrotic mosaic virus Reviewed

    Yuri Tajima, Hiro-oki Iwakawa, Kiwamu Hyodo, Masanori Kaido, Kazuyuki Mise, Tetsuro Okuno

    VIROLOGY   509   152 - 158   2017.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    The bipartite genomic RNAs of red clover necrotic mosaic virus (RCNMV) lack a 5' cap and a 3' poly(A) tail. RNA1 encodes viral replication proteins, and RNA2 encodes a movement protein (MP). These proteins are translated in a cap-independent manner. We previously identified two cis-acting RNA elements that cooperatively recruit eukaryotic translation initiation factor (eIF) complex eIF4F or eIFiso4F to RNA1. Such cis-acting RNA elements and host factors have not been identified in RNA2. Here we found that translation of RNA1 was significantly compromised in Arabidopsis thaliana carrying eif4f mutation. RNA1 replicated efficiently in eifiso4fl mutants, suggesting vigorous translation of the replication proteins from RNA1 in the plants. In contrast, MP accumulation was decreased in eifiso4f1 mutants but not in eif4f mutants. Collectively, these results suggest that RCNMV uses different eIF complexes for translation of its bipartite genomic RNAs, which may contribute to fine-tuning viral gene expression during infection.

    DOI: 10.1016/j.virol.2017.06.015

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  • Roles of superoxide anion and hydrogen peroxide during replication of two unrelated plant RNA viruses in Nicotiana benthamiana Reviewed

    Kiwamu Hyodo, Nobuhiro Suzuki, Kazuyuki Mise, Tetsuro Okuno

    Plant Signaling and Behavior   12 ( 6 )   e1338223   2017.6

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Taylor and Francis Inc.  

    Reactive oxygen species (ROS), including superoxide anion (O2 −), hydrogen peroxide (H2O2), and hydroxyl radical, act as signaling molecules to transduce biotic and abiotic stimuli into stress adaptations in plants. A respiratory burst oxidase homolog B of Nicotiana benthamiana (NbRBOHB) is responsible for O2 − production to inhibit pathogen infection during plant innate immunity. RBOH-derived O2 − can be immediately converted into H2O2 by the action of superoxide dismutase. Interestingly, we recently showed that red clover necrotic mosaic virus (RCNMV), a plant positive-strand RNA [(+)RNA] virus, hijacks the host's ROS-generating machinery during infection. An RCNMV replication protein associates with NbRBOHB and triggers intracellular ROS bursts. These bursts are required for robust viral RNA replication. However, what types of ROS are required for viral replication is currently unknown. Here, we found that RCNMV replication was sensitive to an O2 − scavenger but insensitive to an H2O2 scavenger. Interestingly, replication of another plant (+)RNA virus, brome mosaic virus, was sensitive to both types of scavengers. These results indicate a virus-specific pattern requirement of O2 − and H2O2 for (+)RNA virus replication and suggest a conserved nature of the roles of ROS in (+)RNA virus replication.

    DOI: 10.1080/15592324.2017.1338223

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  • Harnessing host ROS-generating machinery for the robust genome replication of a plant RNA virus Reviewed

    Kiwamu Hyodo, Kenji Hashimoto, Kazuyuki Kuchitsu, Nobuhiro Suzuki, Tetsuro Okuno

    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA   114 ( 7 )   E1282 - E1290   2017.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:NATL ACAD SCIENCES  

    As sessile organisms, plants have to accommodate to rapid changes in their surrounding environment. Reactive oxygen species (ROS) act as signaling molecules to transduce biotic and abiotic stimuli into plant stress adaptations. It is established that a respiratory burst oxidase homolog B of Nicotiana benthamiana (NbRBOHB) produces ROS in response to microbe-associated molecular patterns to inhibit pathogen infection. Plant viruses are also known as causative agents of ROS induction in infected plants; however, the function of ROS in plant-virus interactions remains obscure. Here, we show that the replication of red clover necrotic mosaic virus (RCNMV), a plant positive-strand RNA [(+) RNA] virus, requires NbRBOHB-mediated ROS production. The RCNMV replication protein p27 plays a pivotal role in this process, redirecting the subcellular localization of NbRBOHB and a subgroup II calcium-dependent protein kinase of N. benthamiana (NbCDPKiso2) from the plasma membrane to the p27-containing intracellular aggregate structures. p27 also induces an intracellular ROS burst in an RBOH-dependent manner. NbCDPKiso2 was shown to be an activator of the p27-triggered ROS accumulations and to be required for RCNMV replication. Importantly, this RBOH-derived ROS is essential for robust viral RNA replication. The need for RBOHderived ROS was demonstrated for the replication of another (+) RNA virus, brome mosaic virus, suggesting that this characteristic is true for plant (+) RNA viruses. Collectively, our findings revealed a hitherto unknown viral strategy whereby the host ROS-generating machinery is diverted for robust viral RNA replication.

    DOI: 10.1073/pnas.1610212114

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  • Chloroplast genome sequences of seven strains of the bloom-forming raphidophyte Heterosigma akashiwo Reviewed

    Sergio Seoane, Kiwamu Hyodo, Shoko Ueki

    Genome Announcements   5 ( 41 )   2017

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:American Society for Microbiology  

    We report here the complete chloroplast genome sequences of seven strains of the bloom-forming raphidophyte Heterosigma akashiwo. These ~160-kb sequences contain 124 protein-, 6 rRNA-, and 34 tRNA-coding sequences. Notable sequence variations were observed among these seven sequenced and two previously characterized strains.

    DOI: 10.1128/genomeA.01030-17

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  • Structural Analysis of Long Single-Stranded RNA Molecules with Atomic Force Microscopy Imaging

    Jamie L. Gilmore, Aiko Yoshida, Katashi Deguchi, Suguru Asai, Hideki Aizaki, Masahiro Kumeta, Kiwamu Hyodo, Tetsuro Okuno, Takaji Wakita, Kunio Takeyasu

    3RD INTERNATIONAL MULTIDISCIPLINARY MICROSCOPY AND MICROANALYSIS CONGRESS (INTERM)   186   3 - 9   2017

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPRINGER INTERNATIONAL PUBLISHING AG  

    Characterization of the structure of long RNA molecules (>1 kb) is usually a time-consuming and tedious process. In this study, we have developed an imaging procedure for obtaining images of the extended secondary structures of long RNA molecules combined with automated MATLAB-based data processing algorithms for identification of the domain architecture of the molecules in these images. These algorithms include a molecule autoselection procedure based on height and area thresholding, a morphological thinning procedure to generate skeletons of the molecule in order to analyze the branched structure of the molecules, and a procedure to generate local volume profiles along the main chain of the molecule for identification of domains and prediction of the number of nucleotides comprising each domain. The single-molecule nature of this technique also allows for the identification of varying conformations of the molecule and assessment of the conformational flexibility of the identified domain organization.

    DOI: 10.1007/978-3-319-46601-9_1

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  • Pathogenesis mediated by proviral host factors involved in translation and replication of plant positive-strand RNA viruses Reviewed

    Kiwamu Hyodo, Tetsuro Okuno

    CURRENT OPINION IN VIROLOGY   17   11 - 18   2016.4

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    Viral pathogenesis comes from complex interactions between viruses and hosts. All the processes of viral infection, including translation of viral factors and replication of viral genomes, define viral pathogenesis; therefore, molecular insights into the mechanisms underlying viral replication strategies unambiguously pave the way for our comprehensive understanding of viral pathogenesis and disease outcome, as well as for developing new antiviral strategies against plant virus disease. Recent studies of plant positive-strand RNA [(+)RNA] viruses have advanced our understanding of co-opted host factors and their roles in viral translation and replication. It is becoming clear that plant (+)RNA viruses harness host factors involved in membrane trafficking and lipid metabolism to establish the viral replication complex (VRC). In this review, we aim to discuss the contribution of co-opted host factors in translation and genome replication of plant (+)RNA viruses mainly focusing on those involved in the biogenesis of the VRC, which may act as a central hub in almost all the processes of viral infection as well as viral pathogenesis.

    DOI: 10.1016/j.coviro.2015.11.004

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  • Phosphatidic Acid Produced by Phospholipase D Promotes RNA Replication of a Plant RNA Virus Reviewed

    Kiwamu Hyodo, Takako Taniguchi, Yuki Manabe, Masanori Kaido, Kazuyuki Mise, Tatsuya Sugawara, Hisaaki Taniguchi, Tetsuro Okuno

    PLOS PATHOGENS   11 ( 5 )   e1004909   2015.5

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    Eukaryotic positive-strand RNA [(+) RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+) RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine-and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+) RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLD alpha and PLD beta. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate.

    DOI: 10.1371/journal.ppat.1004909

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  • GAPDH-A Recruits a Plant Virus Movement Protein to Cortical Virus Replication Complexes to Facilitate Viral Cell-to-Cell Movement Reviewed

    Masanori Kaido, Kazutomo Abe, Akira Mine, Kiwamu Hyodo, Takako Taniguchi, Hisaaki Taniguchi, Kazuyuki Mise, Tetsuro Okuno

    PLOS PATHOGENS   10 ( 11 )   e1004505   2014.11

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    The formation of virus movement protein (MP)-containing punctate structures on the cortical endoplasmic reticulum is required for efficient intercellular movement of Red clover necrotic mosaic virus (RCNMV), a bipartite positive-strand RNA plant virus. We found that these cortical punctate structures constitute a viral replication complex (VRC) in addition to the previously reported aggregate structures that formed adjacent to the nucleus. We identified host proteins that interacted with RCNMV MP in virus-infected Nicotiana benthamiana leaves using a tandem affinity purification method followed by mass spectrometry. One of these host proteins was glyceraldehyde 3-phosphate dehydrogenase-A (NbGAPDH-A), which is a component of the Calvin-Benson cycle in chloroplasts. Virus-induced gene silencing of NbGAPDH-A reduced RCNMV multiplication in the inoculated leaves, but not in the single cells, thereby suggesting that GAPDH-A plays a positive role in cell-to-cell movement of RCNMV. The fusion protein of NbGAPDH-A and green fluorescent protein localized exclusively to the chloroplasts. In the presence of RCNMV RNA1, however, the protein localized to the cortical VRC as well as the chloroplasts. Bimolecular fluorescence complementation assay and GST pulldown assay confirmed in vivo and in vitro interactions, respectively, between the MP and NbGAPDH-A. Furthermore, gene silencing of NbGAPDH-A inhibited MP localization to the cortical VRC. We discuss the possible roles of NbGAPDH-A in the RCNMV movement process.

    DOI: 10.1371/journal.ppat.1004505

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  • Host and viral RNA-binding proteins involved in membrane targeting, replication and intercellular movement of plant RNA virus genomes Reviewed

    K. Hyodo, M. Kaido, T. Okuno

    Frontiers in Plant Science   5   321   2014.7

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    DOI: 10.3389/fpls.2014.00321

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  • Traffic jam on the cellular secretory pathway generated by a replication protein from a plant RNA virus Reviewed

    Kiwamu Hyodo, Masanori Kaido, Tetsuro Okuno

    Plant Signaling and Behavior   9   2014

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:Landes Bioscience  

    Although positive-strand RNA [(+)RNA] viruses have a limited coding capacity, they can replicate efficiently in host cells because of their ability to use host-derived proteins, membranes, lipids, and metabolites, and to rewire cellular trafficking pathways. Previously, we showed that a plant RNA virus, the Red clover necrotic mosaic virus (RCNM V), hijacked Arf1 and Sar1, which are small GTPases that regulate the biogenesis of COPI and COPII vesicles, respectively, for viral RNA replication. These small GTPases are relocated from appropriate subcellular compartments to the viral RNA replication sites by p27 replication protein, which raises the possibility that RCNM V interferes with the cellular secretory pathway. Here, we examined this possibility by using green fluorescent protein-fused rice SCAM P1 and Arabidopsis LRR 84A as secretory pathway marker proteins and showed that p27 inhibited the trafficking of these proteins. RCNM Vmediated inhibition of the host secretion pathway and its possible impact on plant-virus interaction are discussed. © 2014 Landes Bioscience.

    DOI: 10.4161/psb.28644

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  • ADPribosylation factor 1 plays an essential role in the replication of a plant RNA virus Reviewed

    Hyodo K, Mine A, Taniguchi T, Kaido M, Mise K, Taniguchi H, Okuno T

    J Virol.   87 ( 1 )   163 - 176   2013.1

  • Identification of domains in p27 auxiliary replicase protein essential for its association with the endoplasmic reticulum membranes in Red clover necrotic mosaic virus. Reviewed

    Kusumanegara K, Mine A, Hyodo K, Kaido M, Mise K, Okuno T

    Virology   433 ( 1 )   131 - 141   2012.11

  • Differential roles of Hsp70 and Hsp90 in the assembly of the replicase complex of a positive-strand RNA plant virus Reviewed

    Mine A, Hyodo K, Tajima Y, Kusumanegara K, Taniguchi T, Kaido M, Mise K, Taniguchi H, Okuno T

    J Virol.   86 ( 22 )   12091 - 12104   2012.11

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  • Identification ofamino acids in auxiliary replicase protein p27 critical for its RNA-bindingactivity and the assembly of the replicase complex in Red clover necrotic mosaic virus Reviewed

    Hyodo K, Mine A, Iwakawa HO, Kaido M, Mise K, Okuno T

    Virology   413 ( 2 )   300 - 309   2011.5

  • Template recognition mechanisms by replicase proteins differ between bipartitepositive-strand genomic RNAs of a plant virus Reviewed

    Iwakawa HO, Mine A, Hyodo K, An M, Kaido M, Mise K, Okuno T

    J Virol.   85 ( 1 )   497 - 509   2011.1

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  • Interactions between p27 and p88 replicase proteins of Red clover necrotic mosaic virus play an essential role in viral RNA replication and suppression of RNA silencing via the 480-kDaviral replicase complex assembly Reviewed

    Mine A, Hyodo K, Takeda A, Kaido M, Mise K, Okuno T

    Virology   407 ( 2 )   213 - 224   2010.11

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Books

MISC

  • Highjack of a host proviral vacuolar-type H+-ATPase by dianthoviruses

    兵頭究, 首藤丘宇, 近藤秀樹, 鈴木信弘

    日本植物病理学会大会プログラム・講演要旨予稿集   2022   2022

  • Virome analysis of aphid populations that infest the barley field

    近藤秀樹, 藤田美貴, 久野裕, 兵頭究, 鈴木信弘

    日本植物病理学会大会プログラム・講演要旨予稿集   2021   2021

  • Identification and characterization of host factors involved in plant RNA virus replication

    HYODO K.

    Japanese Journal of Phytopathology   87 ( 3 )   131 - 131   2021

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    DOI: 10.3186/jjphytopath.87.131

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  • 宿主足場タンパク質RACK1のハイジャックによる植物ウイルス増殖機構

    兵頭究, 鈴木信弘, 奥野哲郎

    日本植物病理学会報   85 ( 1 )   2019

  • 植物ウイルス感染の抗糸状菌植物免疫への影響

    兵頭究, 鈴木信弘

    日本植物病理学会大会プログラム・講演要旨予稿集   2019   2019

  • 光化学系II修復サイクルでのFtsHプロテアーゼ自身の品質管理の重要性

    加藤裕介, 兵頭究, 坂本亘

    日本植物生理学会年会(Web)   59th   2018

  • 宿主足場タンパク質RACK1は植物RNAウイルスの増殖を正に制御する

    兵頭究, 鈴木信弘, 奥野哲郎

    日本植物病理学会大会プログラム・講演要旨予稿集   2018   2018

  • 植物ウイルス感染がパターン誘導性免疫に及ぼす影響

    兵頭究

    日本植物病理学会植物感染生理談話会論文集   ( 53 )   2018

  • 植物RNAウイルスの複製機構

    兵頭究

    植物ウイルス病研究会レポート   ( 13 )   2018

  • 活性酸素種は植物RNAウイルス増殖を正に制御する

    兵頭究, 鈴木信弘, 奥野哲郎

    日本植物病理学会大会プログラム・講演要旨予稿集   2016   2016

  • 活性酸素種産生機構の転用による植物RNAウイルスの増殖戦略 Reviewed

    兵頭 究, 海道真典, 三瀬和之, 奥野哲郎

    平成27年度日本植物病理学会大会   2015   2015.3

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  • HMG-CoA synthaseはRed clover necrotic mosaic virusの複製に必要である Reviewed

    高橋佳奈, 兵頭 究, 海道真典, 三瀬和之, 奥野哲郎

    平成27年度日本植物病理学会大会   2015   2015.3

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  • Red clover necrotic mosaic virus RNA2の5'UTRはプラス鎖とマイナス鎖合成いずれにも関与する Reviewed

    永井比加里, 田島由理, 兵頭 究, 海道真典, 三瀬和之, 奥野哲郎

    平成27年度日本植物病理学会大会   2015   2015.3

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  • 毒薬変じて薬となる? : 植物を助けるウイルス(バイオミディア)

    兵頭 究

    生物工学会誌 : seibutsu-kogaku kaishi   93 ( 10 )   630 - 630   2015

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  • ダイアンソウイルスのゲノムRNA複製における宿主Phospholipase Dの機能解析 Reviewed

    兵頭 究, 海道真典, 三瀬和之, 奥野哲郎

    平成26年度日本植物病理学会大会   2014   2014.6

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  • Red clover necrotic mosaic virusの複製酵素タンパク質p27のアセチル化はウイルス感染に関与している Reviewed

    阪田星子, 兵頭 究, 海道真典, 三瀬和之, 奥野哲郎

    平成25年度日本植物病理学会関西部会   80 ( 1 )   2013.9

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  • Red clover necrotic mosaic virus感染のRNAサイレンシング関連遺伝子mRNA蓄積に及ぼす影響 Reviewed

    俵 健二, 兵頭 究, 峯 彰, 海道真典, 三瀬和之, 奥野哲郎

    平成24年度日本植物病理学会関西部会   79 ( 1 )   2012.9

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  • Functional analysis of host small GTPase ADP-ribosylation factor 1 in a positive-strand plant RNA virus

    Hyodo, K, Mine, A, Kaido, M, Mise, K, Okuno, T

    31st Annual Meeting of American Society for Virology. July 21⎯25, 2012, Madison, Wisconsin, USA   2012.7

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  • 植物プラスセンスRNAウイルスのゲノム複製における宿主small GTPase ADP-ribosylation factor 1の機能解析 Reviewed

    兵頭 究, 峯 彰, 海道真典, 三瀬和之, 奥野哲郎

    平成24年度日本植物病理学会大会   2012   2012.3

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  • ADP-ribosylation factor 1 plays an important role in RNA replication of Red clover necrotic mosaic virus

    Hyodo, K, Mine, A, Kaido, M, Mise, K, Okuno, T

    15th International Congress of Virology. September 11-16, 2011, Sapporo, Japan   2011.9

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  • Auxiliary replicase protein p27 of Red clover necrotic mosaic virus plays multiple roles in an early replication process

    Hyodo, K, Mine, A, Iwakawa, H.-O, Kaido, M, Mise, K, Okuno, T

    33rd Annual Meeting of the Molecular Biology Society of Japan   2010.12

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  • RNA binding activity of Red clover necrotic mosaic virus Replication protein p27 plays important roles in the early replication steps of viral genomic RNA2

    Hyodo, K, Mine, A, Iwakawa, H.-O, Kaido, M, Mise, K, Okuno, T

    29th Annual Meeting of American Society for Virology. July 17-21, 2010, Bozeman, Montana, USA   2010.7

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  • Red clover necrotic mosaic virus RNA複製酵素成分タンパク質p27のRNA結合活性はウイルスゲノムRNA2の複製初期段階に必要である Reviewed

    兵頭 究, 峯 彰, 岩川弘宙, 海道真典, 三瀬和之, 奥野哲郎

    平成22年度日本植物病理学会大会   2010   2010.4

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  • Red clover necrotic mosaic virus RNA複製酵素成分タンパク質p27はウイルスRNAの初期複製段階において様々な役割を担っている

    兵頭究, 峯彰, 岩川弘宙, 海道真典, 三瀬和之, 奥野哲郎

    日本ウイルス学会学術集会プログラム・抄録集   58th   2010

  • Red clover necrotic mosaic virus RNA複製酵素成分タンパク質におけるウイルスRNAの膜へのリクルートに関わる機能ドメイン解析

    兵頭 究, 峯 彰, 岩川弘宙, 海道真典, 三瀬和之, 奥野哲郎

    第57回日本ウイルス学会学術集会   57th   2009.10

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Awards

  • 学術奨励賞

    2021   日本植物病理学会  

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Research Projects

  • 作物超個体における根圏RNAウイルス叢の実体解明とその生態学的役割

    Grant number:23H02214  2023.04 - 2027.03

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    近藤 秀樹, 久野 裕, 兵頭 究, 鈴木 信弘

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    Grant amount:\18590000 ( Direct expense: \14300000 、 Indirect expense:\4290000 )

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  • 実験室進化から紐解く抗ウイルス免疫打破株の出現と耐性機構

    Grant number:22K19183  2022.06 - 2025.03

    日本学術振興会  科学研究費助成事業 挑戦的研究(萌芽)  挑戦的研究(萌芽)

    兵頭 究

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    Grant amount:\6370000 ( Direct expense: \4900000 、 Indirect expense:\1470000 )

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  • Frontier in mycoimmunity research and its new developments in phytopathology

    Grant number:21H04727  2021.04 - 2025.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)  Grant-in-Aid for Scientific Research (A)

    鈴木 信弘, 近藤 秀樹, 兵頭 究

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    Grant amount:\41600000 ( Direct expense: \32000000 、 Indirect expense:\9600000 )

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  • MAPKカスケードを巡る植物-ウイルス間相互作用の解明

    Grant number:21H02198  2021.04 - 2024.03

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    兵頭 究

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    Grant amount:\17550000 ( Direct expense: \13500000 、 Indirect expense:\4050000 )

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  • 作物根圏におけるウイルス叢の多様性とその感染動態から紐解く生態的意義

    Grant number:20H02987  2020.04 - 2023.03

    日本学術振興会  科学研究費助成事業 基盤研究(B)  基盤研究(B)

    近藤 秀樹, 久野 裕, 鈴木 信弘, 兵頭 究

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    Grant amount:\17680000 ( Direct expense: \13600000 、 Indirect expense:\4080000 )

    本課題では、ムギ類生存圏(特に根系)におけるウイルス叢の多様性・普遍性や動態を紐解き、さらにそれらの未知なる生態学的役割の一端に迫ることを目指している。以下に本年度の研究実績を示す。
    柱①根圏に存在する主要な菌類・昆虫ウイルス群の宿主探索:初年度に引き続き、ムギ類(オオムギ・コムギ)の地上部・根系、さらにアブラムシ、うどんこ病菌などのRNAseqデータを取得した。得られたデータセットはウイルス配列の確認作業や分子系統解析を進めている。さらに、北海道のコムギサンプルより見出された新規フレキシウイルス(WVQ)の解析の結果,当該圃場に三系統が存在し、ライムギにも感染できること、さらに土壌伝染性ウイルスの可能性が高いことを見出している。根系ウイルス叢のリザーバー探索については、本年度はオオムギ根のRNAseqデータに含まれる微生物リードの抽出と配列相同性解析により、微生物叢の概要を調査した。
    柱②根圏ウイルスの生物界を跨ぐ水平伝搬ポテンシャルと宿主への影響:昨年度より継続中のルテオウイルスなど新規植物ウイルスのゲノム解析を進めており、RT-PCRおよびRLM-RACE解析により全長ゲノムRNA配列を確認・決定した。また、圃場のうどんこ病菌のウイルスについては、今年度はdsRNAを鋳型にした全長cDNAのPCR増幅法の検討を進め、そのアンプリコン配列解析により未同定のゲノム末端配列の解析を進めている。
    柱③根圏ウイルス叢の年次変動とムギ類ウイルスの病原性の(再)評価:核酸抽出を伴わない簡易ウイルス診断法(RT-PCRをベースとする)の条件を設定し、一部圃場サンプル(葉)でルテオウイルス等の検出を進めている。現在、圃場オオムギサンプル(保存している過年度のを含む)について網羅的に検定すすめている。また、アブラムシ媒介性新規植物ウイルスについては、チャンバー内試験にて病原性評価を進めている。

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  • 植物/微生物生態系恒常性制御における植物ウイルスの役割

    Grant number:19H04836  2019.04 - 2021.03

    日本学術振興会  科学研究費助成事業 新学術領域研究(研究領域提案型)  新学術領域研究(研究領域提案型)

    兵頭 究

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    Grant amount:\6500000 ( Direct expense: \5000000 、 Indirect expense:\1500000 )

    環境中において植物は、ウイルス・真菌・細菌を含む、多種類の病原・非病原性微生物叢との相互作用によってその生理状態が規定される。本研究では、このような「エコスフィアー」における、植物ウイルスのレギュレーターとしての役割の解明を目的とする。研究代表者は、red clover necrotic mosaic virus (以下、RCNMV) をモデルウイルスとして、植物ウイルスが抗糸状菌/抗細菌免疫応答に対し、それぞれ正/負に作用するという極めて興味深い現象を見出した。このことは、ウイルスが植物免疫システムへの干渉を介して他の微生物による植物への感染を制御する「植物/微生物生態系恒常性のレギュレーターである」可能性を示唆する。本仮説を実証し、その普遍性・特異性の解明を目指す。
    これまでの研究から、RCNMV感染葉で見られるキチン(糸状菌由来免疫エリシター)誘導性MAPK活性化の増強は宿主足場タンパク質RACK1 (receptor for activated C kinase 1) に依存することが明らかとなった。RCNMVの複製酵素タンパク質p27はRACK1と相互作用し、RACK1とMAPキナーゼとの複合体形成を促進した。本現象の普遍性・特異性を明らかにするため、RCNMVと系統学的に近縁のトムブスウイルス科に属するウイルスの種々の複製酵素タンパク質がキチン誘導性MAPK活性化に及ぼす影響を解析した。その結果、興味深いことに、キチン誘導性MAPK活性化を (i) 促進するもの、 (ii) 抑制するもの、 (iii) 影響を与えないもの、の3パターンが見られた。以上の結果から、植物ウイルスが植物免疫に対して及ぼす影響は実に多様である可能性が示唆された。

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  • Co-opting of a host proton pump for replication of plant RNA viruses

    Grant number:19K15841  2019.04 - 2021.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

    HYODO Kiwamu

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    Grant amount:\4160000 ( Direct expense: \3200000 、 Indirect expense:\960000 )

    Plant viruses are important pathogens that cause serious crop losses worldwide. Because of the limited number of virally encoded proteins, plant viruses need to subvert the host cell machinery for their own functions, ultimately creating a cellular environment favorable to the infection. For this purpose, plant viruses co-opt an array of host-derived factors (referred to as proviral host factors) to establish viral infection, in which viruses remodel their functions to facilitate every step of the viral life cycle. The identification of the global landscape of plant-virus interactions at the molecular level advances the understanding of the viral infection process and may assist in the development of novel antiviral strategies. This study identified the host vacuolar-type H+ ATPase as a new proviral host factor for several plant positive-sense single-stranded RNA viruses.

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  • Frontier of research on antiviral immunity in phytopathogenic filamentous fugi

    Grant number:17H01463  2017.04 - 2021.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)  Grant-in-Aid for Scientific Research (A)

    Suzuki Nobuhiro

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    Grant amount:\41990000 ( Direct expense: \32300000 、 Indirect expense:\9690000 )

    The objective of this project is to explore RNA silencing (RNAi) against fungal viruses in plant pathogenic filamentous fungi. A great progress has been made, leading to several breakthroughs: 1) Discovery of RNAi mediated antiviral defense that requires Dicer but not AGO in the chestnut blight fungus, 2) Identification of the SAGA complex as a transcriptional regulator of fungal RNA silencing, 3) Discovery of a novel antiviral defense mechanism by which virus-induced symptom expression is alleviated by transcriptional upregulation of many host genes upon virus infection in C. parasitica, and 4) Identification of Dicer and SAGA (universal transcriptional coactivator) as the key transcriptional regulators in the new defense, indicating the dual role of Dicer at the post-transcriptional and transcriptional levels. These findings will bring about a paradigm shift in RNAi. Fungi are now being established as the third position next to animals and plants in antiviral defense research.

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  • 植物ウイルス:細菌/糸状菌感染における制御因子

    Grant number:17H05818  2017.04 - 2019.03

    日本学術振興会  科学研究費助成事業 新学術領域研究(研究領域提案型)  新学術領域研究(研究領域提案型)

    兵頭 究

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    Grant amount:\6760000 ( Direct expense: \5200000 、 Indirect expense:\1560000 )

    野外環境中における植物は,ウイルス・真菌・細菌を含む,多種類の病原・非病原微生物叢との相互作用によってその生理状態が規定される.本研究は,このような「エコ・スフィアー」におけるレギュレーターとしての,植物ウイルスの役割の解明を目的とする.特に,ある種の植物ウイルス( red clover necrotic mosaic virus: RCNMV )が細菌・糸状菌に対して有効な植物免疫システムへ干渉することに着目し,ウイルス・植物を含む多者間相互作用を分子レベルで明らかにすることを目指す.
    植物は,微生物由来の分子パターン (PAMPs) を異物として認識し,免疫反応を活性化する機構を持っており,前年度に得られた研究結果から,RCNMV感染が,宿主植物のPAMPs誘導性免疫を撹乱することが示唆されている.
    本年度は,MAPK活性化を指標に,植物免疫に干渉するコアウイルス因子の同定を行った.その結果,ウイルス複製酵素タンパク質p27が植物免疫に影響を与える責任因子であることが明らかとなった.そこで次に,p27によるPAMPs誘導性MAPK活性化への干渉機構に迫るため,宿主因子の同定を試みた.その結果,p27と相互作用し,かつPAMPs誘導性MAPK活性化に関わる宿主足場タンパク質RACK1(receptor for activated C kinase 1)を同定することができた.RACK1ノックダウン植物ではp27存在時に見られる糸状菌由来PAMP誘導性MAPK活性化の変動が見られないことから,RCNMVはp27を介してRACK1に作用し,MAPKカスケードに影響を及ぼすと考えられる.さらに,RACK1の機能解析から,RCNMV増殖におけるRACK1の役割を明らかとした.

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  • Analysis of the molecular mechanism by which ROS regulate the function of a plant virus protein

    Grant number:17K15229  2017.04 - 2019.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)  Grant-in-Aid for Young Scientists (B)

    Hyodo Kiwamu

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    Grant amount:\4420000 ( Direct expense: \3400000 、 Indirect expense:\1020000 )

    Red clover necrotic mosaic virus (RCNMV), a plant positive-strand RNA [(+)RNA] virus, hijacks the host's reactive oxygen species (ROS)-generating machinery during infection. However, it remains largely unknown how ROS promote viral replication. Here, we found that RCNMV replication was sensitive to an O2- scavenger but insensitive to an H2O2 scavenger. To understand the molecular mechanism by which ROS regulate viral replication, we tried to identify post-translational modification, including protein oxidation, of viral replication protein induced by ROS. However, unfortunately, we could not identify such post-translational protein modification. We also provide evidence suggesting that RCNMV hijacks RACK1, a host scaffold protein, to facilitate ROS accumulation induced by a viral replication protein and viral RNA replication.

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  • Virus-mediated suppression of plant innate immunity

    Grant number:15H06420  2015.08 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up  Grant-in-Aid for Research Activity Start-up

    Hyodo Kiwamu

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    Grant amount:\3770000 ( Direct expense: \2900000 、 Indirect expense:\870000 )

    Plants have a multitier surveillance system that recognizes invading microbial pathogens using plasma membrane-localized and intracellular immune receptors. An RBOH (respiratory burst oxidase homolog) protein plays a key role in plant innate immunity. In this study, we found that a plant virus hijacks a host ROS generating enzyme RBOH for its multiplication. We also found that a plant virus infection can interfere with host immune responses.

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  • Search and functional analysis of host proteins that positively or negatively regulate the replication of a plant RNA virus

    Grant number:15H04456  2015.04 - 2018.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)  Grant-in-Aid for Scientific Research (B)

    Okuno Tetsuro

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    Grant amount:\16640000 ( Direct expense: \12800000 、 Indirect expense:\3840000 )

    We investigated molecular mechanisms underlying the replication of RNA viruses using a legume plant-infecting Red clover necrotic mosaic virus (RCNMV) as a model virus. We found that RCNMV modifies cellular membranes to create a viral RNA replication factory, and changes cellular environment by harnessing host oxygen-generating machinery to facilitate virus RNA replication. We identified many host proteins which positively or negatively regulate virus RNA replication. Molecular identification of host factors and elucidation of their functions in the viral infection process could assist in the development of novel anti-viral strategies.

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  • 植物RNAウイルスの複製における細胞内膜輸送系の役割の解明

    Grant number:12J03994  2012 - 2013

    日本学術振興会  科学研究費助成事業 特別研究員奨励費  特別研究員奨励費

    兵頭 究

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    Grant amount:\1800000 ( Direct expense: \1800000 )

    申請研究者はRCNMVの複製酵素タンパク質に結合する宿主タンパク質を二段階共免疫沈降法および質量分析により同定した. ゴルジ体からERへの輸送を担うCOPI輸送小胞の形成に必須であるADP-ribosylation factor 1 (Arfl), ERからゴルジ体への輸送を担うCOPII輸送小胞系の制御因子であるsecretion-associated RAS-related1 (Sar1), さらにホスファチジン酸(PA)の産生に関わるphospholipase D (PLD)などを新たな宿主因子候補タンパク質として同定することに成功した. RCNMVのRNA複製におけるArflおよびSarlの機能については昨年度に報告した(Hyodo et al., 2013).
    RCNMV感染が細胞内膜輸送系に与える影響をER-ゴルジ体の経路を通って細胞膜へと輸送されることが知られているタンパク質をマーカーとして調べた. RCNMV感染細胞ではこれらのマーカー・タンパク質の細胞膜への輸送が正常に行われず, 細胞内でっまっていることを発見した. p27を発現させた細胞でもこの現象は観察された. 従ってRCNMVはp27を介して膜輸送系が撹乱すると考えられる. 本成果はPlant Signaling & Behaviorに報告した(Hyodo et al., 2014).
    PLDノックダウン植物ではRCNMVの感染が抑制されることから, PLDはウイルス感染において必要な宿主因子であることが明らかとなった. さらに, PLDによるPA産生はRCNMV複製に必要であることが分かった. RCNMV感染葉ではPAの蓄積量が約3倍程度にまで増加することから, RCNMVはPLDを活性化し, ウイルス複製に適したPAを多く産生させることで自身の感染を有利に進めていると考えられた. 本成果は特定のリン脂質が直接的にウイルス複製を促進することを証明した初めての知見であり, そのインパクトは大きいと考えられる, 本成果は現在原著論文として投稿準備中である.

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Class subject in charge

  • Plant Virology (2023academic year) 1st semester  - 木3,木4

  • Plant Virology (2022academic year) 1st semester  - 木3,木4

  • Plant Virology (2021academic year) 1st semester  - 木3,木4

  • Plant Virology (2020academic year) 1st semester  - 木3,木4