研究者詳細 - 近藤　秀樹

論文 - 近藤　秀樹

分割表示 144 件中 101 - 120 件目／全件表示 >>

Amyloplast-Localized SUBSTANDARD STARCH GRAIN4 Protein Influences the Size of Starch Grains in Rice Endosperm 査読

Ryo Matsushima, Masahiko Maekawa, Miyako Kusano, Hideki Kondo, Naoko Fujita, Yasushi Kawagoe, Wataru Sakamoto

PLANT PHYSIOLOGY 164 ( 2 ) 623 - 636 2014年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC PLANT BIOLOGISTS

Starch is a biologically and commercially important polymer of glucose and is synthesized to form starch grains (SGs) inside amyloplasts. Cereal endosperm accumulates starch to levels that are more than 90% of the total weight, and most of the intracellular space is occupied by SGs. The size of SGs differs depending on the plant species and is one of the most important factors for industrial applications of starch. However, the molecular machinery that regulates the size of SGs is unknown. In this study, we report a novel rice (Oryza sativa) mutant called substandard starch grain4 (ssg4) that develops enlarged SGs in the endosperm. Enlargement of SGs in ssg4 was also observed in other starch-accumulating tissues such as pollen grains, root caps, and young pericarps. The SSG4 gene was identified by map-based cloning. SSG4 encodes a protein that contains 2,135 amino acid residues and an amino-terminal amyloplast-targeted sequence. SSG4 contains a domain of unknown function490 that is conserved from bacteria to higher plants. Domain of unknown function490-containing proteins with lengths greater than 2,000 amino acid residues are predominant in photosynthetic organisms such as cyanobacteria and higher plants but are minor in proteobacteria. The results of this study suggest that SSG4 is a novel protein that influences the size of SGs. SSG4 will be a useful molecular tool for future starch breeding and biotechnology.

DOI： 10.1104/pp.113.229591

Nucleo-cytoplasmic shuttling of VPg encoded by Wheat yellow mosaic virus requires association with the coat protein 査読

Liying Sun, Bian Jing, Ida Bagus Andika, Yingchun Hu, Bingjian Sun, Rong Xiang, Hideki Kondo, Jianping Chen

JOURNAL OF GENERAL VIROLOGY 94 ( Pt 12 ) 2790 - 2802 2013年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC GENERAL MICROBIOLOGY

VPg (virus protein, genome-linked) is a multifunctional protein that plays important roles in viral multiplication in the cytoplasm. However, a number of VPgs encoded by plant viruses target the nucleus and this appears to be biologically significant. These VPgs may therefore be translocated between nuclear and cytoplasmic compartments during virus infection, but such nucleo-cytoplasmic transport has not been demonstrated. We report that VPg encoded by Wheat yellow mosaic virus (WYMV, genus Bymovirus, family Potyviridae) accumulated in both the nucleus and cytoplasm of infected cells, but localized exclusively in the nucleus when expressed alone in plants. Computational analyses predicted the presence of a nuclear localization signal (NLS) and a nuclear export signal (NES) in WYMV VPg. Mutational analyses showed that both the N-terminal and the NLS domains of VPg contribute to the efficiency of nuclear targeting. In vitro and in planta assays indicated that VPg interacts with WYMV coat protein (CP) and proteinase 1 (P1) proteins. Observation of VPg fused to a fluorescent protein and subcellular fractionation experiments showed that VPg was translocated to the cytoplasm when co-expressed with CP, but not with P1. Mutations in the NES domain or treatment with leptomycin B prevented VPg translocation to the cytoplasm when co-expressed with CP. Our results suggest that association with CP facilitates the nuclear export of VPg during WYMV infection.

DOI： 10.1099/vir.0.055830-0

Nyamiviridae: proposal for a new family in the order Mononegavirales. 国際誌

Jens H Kuhn, Sadia Bekal, Yíngyún Caì, Anna N Clawson, Leslie L Domier, Marieke Herrel, Peter B Jahrling, Hideki Kondo, Kris N Lambert, Kathie A Mihindukulasuriya, Norbert Nowotny, Sheli R Radoshitzky, Urs Schneider, Peter Staeheli, Nobuhiro Suzuki, Robert B Tesh, David Wang, Lin-Fa Wang, Ralf G Dietzgen

Archives of virology 158 ( 10 ) 2209 - 26 2013年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

Nyamanini virus (NYMV) and Midway virus (MIDWV) are unclassified tick-borne agents that infect land birds and seabirds, respectively. The recent molecular characterization of both viruses confirmed their already known close serological relationship and revealed them to be nonsegmented, single- and negative-stranded RNA viruses that are clearly related to, but quite distinct from, members of the order Mononegavirales (bornaviruses, filoviruses, paramyxoviruses, and rhabdoviruses). A third agent, soybean cyst nematode virus 1 (SbCNV-1, previously named soybean cyst nematode nyavirus), was recently found to be an additional member of this new virus group. Here, we review the current knowledge about all three viruses and propose classifying them as members of a new mononegaviral family, Nyamiviridae.

DOI： 10.1007/s00705-013-1674-y

Biological and genetic diversity of plasmodiophorid-transmitted viruses and their vectors 査読

Tetsuo Tamada, Hideki Kondo

JOURNAL OF GENERAL PLANT PATHOLOGY 79 ( 5 ) 307 - 320 2013年9月

記述言語：英語出版者・発行元：SPRINGER JAPAN KK

About 20 species of viruses belonging to five genera, Benyvirus, Furovirus, Pecluvirus, Pomovirus and Bymovirus, are known to be transmitted by plasmodiophorids. These viruses have all positive-sense, single-stranded RNA genomes that consist of two to five RNA components. Three species of plasmodiophorids are recognized as vectors: Polymyxa graminis, P. betae, and Spongospora subterranea. The viruses can survive in soil within the long-lived resting spores of the vector. There are biological and genetic variations in both virus and vector species. Many of the viruses are causal agents of important diseases in major crops such as rice, wheat, barley, rye, sugar beet, potato, and groundnut. Control is dependent on the development of resistant cultivars. During the last half century, several virus diseases have rapidly spread worldwide. For six major virus diseases, we address their geographical distribution, diversity, and genetic resistance.

DOI： 10.1007/s10327-013-0457-3

A novel virus in the family Hypoviridae from the plant pathogenic fungus Fusarium graminearum 査読

Shuangchao Wang, Hideki Kondo, Liang Liu, Lihua Guo, Dewen Qiu

VIRUS RESEARCH 174 ( 1-2 ) 69 - 77 2013年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE BV

A double-stranded (ds) RNA element, sized at approximately 13 kb pairs, was purified from a field isolate, HN10, of Fusariumgraminearum.The coding strand of the dsRNA was 13,023 nucleotides (nt) long (excluding the 3' poly(A) tail) and was predicted to contain two discontiguous open reading frames (ORF A and ORF B). The 5' proximal ORF A of 531 nt encoded a protein of 176 amino acids (aa), and a BLAST search showed it to be similar to the putative papain-like protease domains encoded by Valsa ceratosperma hypovirus 1 (35% identity) and Cryphonectria hypovirus 4 (CHV4) (31% identity). The 3' proximal ORF B of 11,118 nt encoded a large polyprotein with three conserved domains, including papain-like protease, RNA-dependent RNA polymerase and RNA helicase domains. The polyprotein shared significant aa identities with CHV1 (32%) and CHV2 (32%). Both the genome organization and phylogenetic analysis suggested that the characterized RNA represented a novel hypovirus, designated "Fusarium graminearum hypovirus 1 (FgHV1)", which was closely related to CHV1 and CHV2 in the Hypoviridae family. Elimination of the virus resulted in no dramatic phenotypic alteration of the fungus. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.virusres.2013.03.002

A Novel Victorivirus from a Phytopathogenic Fungus, Rosellinia necatrix, Is Infectious as Particles and Targeted by RNA Silencing 査読

Sotaro Chiba, Yu-Hsin Lin, Hideki Kondo, Satoko Kanematsu, Nobuhiro Suzuki

JOURNAL OF VIROLOGY 87 ( 12 ) 6727 - 6738 2013年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC MICROBIOLOGY

A novel victorivirus, termed Rosellinia necatrix victorivirus 1 (RnVV1), was isolated from a plant pathogenic ascomycete, white root rot fungus Rosellinia necatrix, coinfected with a partitivirus. The virus was molecularly and biologically characterized using the natural and experimental hosts (chestnut blight fungus, Cryphonectria parasitica). RnVV1 was shown to have typical molecular victorivirus attributes, including a monopartite double-stranded RNA genome with two open reading frames (ORFs) encoding capsid protein (CP) and RNA-dependent RNA polymerase (RdRp), a UAAUG pentamer presumed to facilitate the coupled termination/reinitiation for translation of the two ORFs, a spherical particle structure similar to 40 nm in diameter, and moderate levels of CP and RdRp sequence identity (34 to 58%) to those of members of the genus Victorivirus within the family Totiviridae. A reproducible transfection system with purified RnVV1 virions was developed for the two distinct fungal hosts. Transfection assay with purified RnVV1 virions combined with virus elimination by hyphal tipping showed that the effects of RnVV1 on the phenotype of the natural host were negligible. Interestingly, comparison of the RNA silencing-competent (standard strain EP155) and -defective (Delta dcl-2) strains of C. parasitica infected with RnVV1 showed that RNA silencing acted against the virus to repress its replication, which was restored by coinfection with hypovirus or transgenic expression of an RNA silencing suppressor, hypovirus p29. Phenotypic changes were observed in the Delta dcl-2 strain but not in EP155. This is the first reported study on the host range expansion of a Totiviridae member that is targeted by RNA silencing.

DOI： 10.1128/JVI.00557-13

Identification of a movement protein of Mirafiori lettuce big-vein ophiovirus 査読

Akihiro Hiraguri, Shoko Ueki, Hideki Kondo, Koji Nomiyama, Takumi Shimizu, Tamaki Ichiki-Uehara, Toshihiro Omura, Nobumitsu Sasaki, Hiroshi Nyunoya, Takahide Sasaya

Journal of General Virology 94 ( 5 ) 1145 - 1150 2013年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

Mirafiori lettuce big-vein virus (MiLBVV) is a member of the genus Ophiovirus, which is a segmented negative-stranded RNA virus. In microprojectile bombardment experiments to identify a movement protein (MP) gene of ophioviruses that can trans-complement intercellular movement of an MP-deficient heterologous virus, a plasmid containing an infectious clone of a tomato mosaic virus (ToMV) derivative expressing the GFP was co-bombarded with plasmids containing one of three genes from MiLBVV RNAs 1, 2 and 4 onto Nicotiana benthamiana. Intercellular movement of the movement-defective ToMV was restored by co-expression of the 55 kDa protein gene, but not with the two other genes. Transient expression in epidermal cells of N. benthamiana and onion showed that the 55 kDa protein with GFP was localized on the plasmodesmata. The 55 kDa protein encoded in the MiLBVV RNA2 can function as an MP of the virus. This report is the first to describe an ophiovirus MP. © 2013 SGM.

DOI： 10.1099/vir.0.050005-0

Identification of the amino acid residues and domains in the cysteine-rich protein of Chinese wheat mosaic virus that are important for RNA silencing suppression and subcellular localization 査読

Liying Sun, Ida Bagus Andika, Hideki Kondo, Jianping Chen

Molecular Plant Pathology 14 ( 3 ) 265 - 278 2013年4月

記述言語：英語掲載種別：研究論文（学術雑誌）

Cysteine-rich proteins (CRPs) encoded by some plant viruses in diverse genera function as RNA silencing suppressors. Within the N-terminal portion of CRPs encoded by furoviruses, there are six conserved cysteine residues and a Cys-Gly-X-X-His motif (Cys, cysteine
Gly, glycine
His, histidine
X, any amino acid residue) with unknown function. The central domains contain coiled-coil heptad amino acid repeats that usually mediate protein dimerization. Here, we present evidence that the conserved cysteine residues and Cys-Gly-X-X-His motif in the CRP of Chinese wheat mosaic virus (CWMV) are critical for protein stability and silencing suppression activity. Mutation of a leucine residue in the third coiled-coil heptad impaired CWMV CRP activity for suppression of local silencing, but not for the promotion of cell-to-cell movement of Potato virus X (PVX). Inplanta and invitro analysis of wild-type and mutant proteins indicated that the ability of the CRP to self-interact was correlated with its suppression activity. Deletion of up to 40 amino acids at the C-terminus did not abolish suppression activity, but disrupted the association of CRP with endoplasmic reticulum (ER), and reduced its activity in the enhancement of PVX symptom severity. Interestingly, a short region in the C-terminal domain, predicted to form an amphipathic α-helical structure, was responsible for the association of CWMV CRP with ER. Overall, our results demonstrate that the N-terminal and central regions are the functional domains for suppression activity, whereas the C-terminal region primarily functions to target CWMV CRP to the ER. © 2012 The Authors. Molecular Plant Pathology © 2012 Bspp and Blackwell Publishing Ltd.

DOI： 10.1111/mpp.12002

Effects of Defective Interfering RNA on Symptom Induction by, and Replication of, a Novel Partitivirus from a Phytopathogenic Fungus, Rosellinia necatrix 査読

Sotaro Chiba, Yu-Hsin Lin, Hideki Kondo, Satoko Kanematsu, Nobuhiro Suzuki

JOURNAL OF VIROLOGY 87 ( 4 ) 2330 - 2341 2013年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC MICROBIOLOGY

A novel mycovirus termed Rosellinia necatrix partitivirus 2 (RnPV2), isolated from a phytopathogenic fungus, Rosellinina necatrix strain W57, was molecularly and biologically characterized in both natural and experimental host fungi. Three double-stranded RNA (dsRNA) segments, dsRNA1, dsRNA2, and defective interfering dsRNA1 (DI-dsRNA1), whose sizes were approximately 2.0, 1.8, and 1.7 kbp, respectively, were detected in W57. While the dsRNA2 sequence, encoding the coat protein, was reported previously, dsRNA1 and DI-dsRNA1 were shown to encode competent and defective (truncated) RNA-dependent RNA polymerase, respectively. Artificial introduction of RnPV2 into an RNA silencing-defective, Dicer-like 2 knockout mutant (Delta dcl-2) of a nonnatural host, Cryphonectria parasitica (chestnut blight fungus), resulted in successful infection by the DI-dsRNA1-carrying and -free RnPV2. The DI-dsRNA1-free RnPV2 strain was characterized by a higher ratio of accumulation of the intact dsRNA1 to dsRNA2, enhanced replication and severer symptom expression, compared with the DI-carrying strain. These findings confirmed the nature of DI-dsRNA1 as a DI-RNA. Both viral strains replicated to higher levels in a Delta dcl-2 mutant than in a wild-type C. parasitica fungal strain (EP155) and induced severe symptoms in the Delta dcl-2 mutant but subtle symptoms in EP155, indicating that the host RNA silencing targets the partitivirus. No obvious phenotypic effects of infection by either virus strain were detected in the natural host fungus. These combined results represent the first example of a partitivirus with DI-RNA that alters viral symptom induction in a host-dependent manner.

DOI： 10.1128/JVI.02835-12

Endoplasmic reticulum export and vesicle formation of the movement protein of Chinese wheat mosaic virus are regulated by two transmembrane domains and depend on the secretory pathway 査読

Ida Bagus Andika, Shiling Zheng, Zilong Tan, Liying Sun, Hideki Kondo, Xueping Zhou, Jianping Chen

VIROLOGY 435 ( 2 ) 493 - 503 2013年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

The 37K protein of Chinese wheat mosaic virus (CWMV) belongs to the 30K superfamily of plant virus movement proteins. CWMV 37K trans-complemented the cell-to-cell spread of a movement-defective Potato virus X. CWMV 37K fused to enhanced green fluorescent protein localized to plasmodesmata and formed endoplasmic reticulum (ER)-derived vesicular and large aggregate structures. CWMV 37K has two putative N-terminal transmembrane domains (TMDs). Mutations disrupting TMD1 or TMD2 impaired 37K movement function; those mutants were unable to form ER-derived structures but instead accumulated in the ER. Treatment with Brefeldin A or overexpression of the dominant negative mutant of Sari retained 37K in the ER, indicating that ER export of 37K is dependent on the secretory pathway. Moreover, CWMV 37K interacted with pectin methylesterases and mutations in TMD1 or TMD2 impaired this interaction in planta. The results suggest that the two TMDs regulate the movement function and intracellular transport of 37K. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.viro1.2012.10.024

[Plant rhabdoviruses with bipartite genomes].

Hideki Kondo

Uirusu 63 ( 2 ) 143 - 54 2013年

記述言語：日本語掲載種別：研究論文（学術雑誌）

Members of the family Rhabdoviridae (order Mononegavirales) have a broad range of hosts, including humans, livestock, fish, plants, and invertebrates. They have a nonsegmented negative-sense RNA as the genome. Orchid fleck virus (OFV) is distributed world-wide on several orchid plants and transmitted by the false spider mite, Brevipalpus californicus. Based on its virions morphology and cytopathic effects in the infected cells, OFV was tentatively placed as unassigned plant rhabdoviruses in the sixth ICTV Report. However, the molecular studies reveled that OFV has a unique two-segmented negative-sense RNA genome that resembles monopartite genomes of plant nucleorhabdoviruses. In this review, we describe the current knowledge on the genome structure and gene expression strategy of OFV, the possible mechanism of nuclear viroplasm formation, and the taxonomical consideration of the virus as well.

Viruses of the white root rot fungus, Rosellinia necatrix. 査読

Kondo H, Kanematsu S, Suzuki N

Advances in virus research 86 177 - 214 2013年

The cysteine-rich proteins of beet necrotic yellow vein virus and tobacco rattle virus contribute to efficient suppression of silencing in roots 査読

Ida Bagus Andika, Hideki Kondo, Masamichi Nishiguchi, Tetsuo Tamada

JOURNAL OF GENERAL VIROLOGY 93 ( Pt 8 ) 1841 - 1850 2012年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC GENERAL MICROBIOLOGY

Many plant viruses encode proteins that suppress RNA silencing, but little is known about the activity of silencing suppressors in roots. This study examined differences in the silencing suppression activity of different viruses in leaves and roots of Nicotiana benthamiana plants. Infection by tobacco mosaic virus, potato virus Y and cucumber mosaic virus but not potato virus X (PVX) resulted in strong silencing suppression activity of a transgene in both leaves and roots, whereas infection by beet necrotic yellow vein virus (BNYVV) and tobacco rattle virus (TRV) showed transgene silencing suppression in roots but not in leaves. For most viruses tested, viral negative-strand RNA accumulated at a very low level in roots, compared with considerable levels of positive-strand genomic RNA. Co-inoculation of leaves with PVX and either BNYVV or TRV produced an increase in PVX negative-strand RNA and subgenomic RNA (sgRNA) accumulation in roots. The cysteine-rich proteins (CRPs) BNYVV p14 and TRV 16K showed weak silencing suppression activity in leaves. However, when either of these CRPs was expressed from a PVX vector, there was an enhancement of PVX negative-strand RNA and sgRNA accumulation in roots compared with PVX alone. Such enhancement of PVX sgRNAs was also observed by expression of CRPs of other viruses and the well-known suppressors HC-Pro and p19 but not of the potato mop-top virus p8 CRP. These results indicate that BNYVV- and TRV-encoded CRPs suppress RNA silencing more efficiently in roots than in leaves.

DOI： 10.1099/vir.0.043513-0

A novel quadripartite dsRNA virus isolated from a phytopathogenic filamentous fungus, Rosellinia necatrix 査読

Yu-Hsin Lin, Sotaro Chiba, Akio Tani, Hideki Kondo, Atsuko Sasaki, Satoko Kanematsu, Nobuhiro Suzuki

VIROLOGY 426 ( 1 ) 42 - 50 2012年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE

Here we report the biological and molecular attributes of a novel dsRNA virus isolated from Rosellinia necatrix, a filamentous phytopathogenic fungus. The virus, termed Rosellinia necatrix quadrivirus 1 (RnQV1), forms rigid spherical particles approximately 45 nm in diameter in infected mycelia. The particles contain 4 dsRNA segments, dsRNA1 to dsRNA4, with a size range of 4.9 to 3.7 kbp, each possessing a single large ORF. A comparison of the virus-infected and -cured isogenic fungal strains suggested that RnQV1 infection has no appreciable phenotypic effects. Phylogenetic analysis using the dsRNA3-encoded RdRp sequence revealed that RnQV1 is more distantly related to quadripartite chrysoviruses than to monopartite totiviruses, and is placed in a distinct group from other mycoviruses. No significant sequence similarities were evident between known proteins and RnQV1 structural proteins shown to be encoded by dsRNA2 or dsRNA4. These suggest that RnQV1 is a novel latent virus, belonging to a new family. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.virol.2012.01.013

The enigmatic genome of Chara australis virus 査読

Adrian J. Gibbs, Marjo Torronen, Anne M. Mackenzie, Jeffery T. Wood, John S. Armstrong, Hideki Kondo, Tetsuo Tamada, Paul L. Keese

JOURNAL OF GENERAL VIROLOGY 92 ( Pt 11 ) 2679 - 2690 2011年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC GENERAL MICROBIOLOGY

Most of the genomic sequence of Chara australis virus (CAV), previously called Chara corallina virus, has been determined. It is a ssRNA molecule of 9065 nt with at least four ORFs. At its 5' end is an ORF encoding a protein of 227 kDa, distantly homologous to the multifunctional replicases of benyviruses and rubiviruses. Next is an ORF encoding a protein of 44 kDa, homologous to the helicases of pestiviruses. The third ORF encodes an unmatched protein of 38 kDa that is probably a movement protein. The fourth and 3'-terminal ORF encodes a protein of 17.7 kDa homologous to the coat proteins of tobamoviruses. The short methyltransferase region of the CAV replicase matches only the C-terminal motif of benyvirus methyltransferases. This and other clues indicate that approximately 11 % and 2 % of the 5' and 3' termini of the complete CAV genome, respectively, are missing from the sequence. The aligned amino acid sequences of the CAV proteins and their nearest homologues contain many gaps but relationships inferred from them were little affected by removal of these gaps. Sequence comparisons show that three of the CAV genes may have diverged from the most closely related genes of other viruses 250-450 million years ago, and the sister relationship between the genes of CAV and those of benyviruses and tobamoviruses, mirroring the ancient sister relationship between charophytes (i.e. the algal host of CAV) and embryophytes (i.e. the plant hosts of tobamoviruses and benyviruses), is congruent with this possibility.

DOI： 10.1099/vir.0.033852-0

Widespread Endogenization of Genome Sequences of Non-Retroviral RNA Viruses into Plant Genomes 査読

Sotaro Chiba, Hideki Kondo, Akio Tani, Daisuke Saisho, Wataru Sakamoto, Satoko Kanematsu, Nobuhiro Suzuki

PLOS PATHOGENS 7 ( 7 ) 2011年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PUBLIC LIBRARY SCIENCE

Non-retroviral RNA virus sequences (NRVSs) have been found in the chromosomes of vertebrates and fungi, but not plants. Here we report similarly endogenized NRVSs derived from plus-, negative-, and double-stranded RNA viruses in plant chromosomes. These sequences were found by searching public genomic sequence databases, and, importantly, most NRVSs were subsequently detected by direct molecular analyses of plant DNAs. The most widespread NRVSs were related to the coat protein (CP) genes of the family Partitiviridae which have bisegmented dsRNA genomes, and included plant-and fungus-infecting members. The CP of a novel fungal virus (Rosellinia necatrix partitivirus 2, RnPV2) had the greatest sequence similarity to Arabidopsis thaliana ILR2, which is thought to regulate the activities of the phytohormone auxin, indole-3-acetic acid (IAA). Furthermore, partitivirus CP-like sequences much more closely related to plant partitiviruses than to RnPV2 were identified in a wide range of plant species. In addition, the nucleocapsid protein genes of cytorhabdoviruses and varicosaviruses were found in species of over 9 plant families, including Brassicaceae and Solanaceae. A replicase-like sequence of a betaflexivirus was identified in the cucumber genome. The pattern of occurrence of NRVSs and the phylogenetic analyses of NRVSs and related viruses indicate that multiple independent integrations into many plant lineages may have occurred. For example, one of the NRVSs was retained in Ar. thaliana but not in Ar. lyrata or other related Camelina species, whereas another NRVS displayed the reverse pattern. Our study has shown that single-and double-stranded RNA viral sequences are widespread in plant genomes, and shows the potential of genome integrated NRVSs to contribute to resolve unclear phylogenetic relationships of plant species.

DOI： 10.1371/journal.ppat.1002146

The Evolutionary History of Beet necrotic yellow vein virus Deduced from Genetic Variation, Geographical Origin and Spread, and the Breaking of Host Resistance 査読

Soutaro Chiba, Hideki Kondo, Masaki Miyanishi, Ida Bagus Andika, Chenggui Han, Tetsuo Tamada

MOLECULAR PLANT-MICROBE INTERACTIONS 24 ( 2 ) 207 - 218 2011年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER PHYTOPATHOLOGICAL SOC

Beet necrotic yellow vein virus (BNYVV) is an economically important pathogen of sugar beet and has been found worldwide, probably as the result of recent worldwide spread. The BNYVV genome consists of four or five RNA components. Here, we report analysis of sequence variation in the RNA3-p25, RNA4-p31, RNA2-CP, and RNA5-p26 genes of 73 worldwide isolates. The RNA3-p25 gene encodes virulence and avirulence factors. These four sets of gene sequences each fell into two to four groups, of which the three groups of p25 formed eight subgroups with different geographical distributions. Each of these subgroup isolates (strains) could have arisen from four original BNYVV population and their mixed infections. The genetic diversity for BNYVV was relatively small. Selection pressure varied greatly depending on the BNYVV gene and geographical location. Isolates of the Italy strain, in which p25 was subject to the strongest positive selection, were able to overcome the Rz1-host resistance gene to differing degrees, whereas other geographically limited strains could not. Resistance-breaking variants were generated by p25 amino acid changes at positions 67 and 68. Our studies suggest that BNYVV originally evolved in East Asia and has recently become a pathogen of cultivated sugar beet followed by the emergence of new resistance-breaking variants.

DOI： 10.1094/MPMI-10-10-0241

Identification and characterization of structural proteins of orchid fleck virus 査読

Hideki Kondo, Takanori Maeda, Tetsuo Tamada

ARCHIVES OF VIROLOGY 154 ( 1 ) 37 - 45 2009年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SPRINGER WIEN

Orchid fleck virus (OFV) has a bipartite negative-sense RNA genome with sequence similarities to plant rhabdoviruses. The non-enveloped bullet-shaped particles of OFV are similar to those of the internal ribonucleoprotein (RNP)-M protein structure of rhabdoviruses, but they are about half the size of typical plant rhabdoviruses. Purified preparations contained intact bullet-shaped and filamentous particles. The filamentous particles showed a tightly coiled coil structure or a coiled structure with a helical twist, which resembles the RNP complex of rhabdoviruses. OFV bullet-shaped particles were structurally stable in solutions containing 2% Triton X-100 and 0.8 M NaCl. Western blot analyses revealed that the bullet-shaped particles contained N, P and M proteins, while filamentous particles contained mainly N and P proteins. In addition, a small amount of the L protein was detected in both types of particles. Thus, the structural proteins of OFV have properties similar to those of rhabdoviruses, except that the particles are non-enveloped and are relatively resistant to detergent-treatment under high-salt conditions.

DOI： 10.1007/s00705-008-0268-6

Role of N-terminal His-rich domain of Oscillatoria brevis Bxa1 in both Ag(I)/Cu(I) and Cd(II)/Zn(II) tolerance. 査読

Nakakihara E, Kondo H, Nakashima S, Ezaki B

The open microbiology journal 3 15 - 22 2009年

The crucial role of mitochondrial regulation in adaptive aluminium resistance in Rhodotorula glutinis 査読

Akio Tani, Chiemi Inoue, Yoko Tanaka, Yoko Yamamoto, Hideki Kondo, Syuntaro Hiradate, Kazuhide Kimbara, Fusako Kawai

MICROBIOLOGY-SGM 154 ( Pt 11 ) 3437 - 3446 2008年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC GENERAL MICROBIOLOGY

Rhodotorula glutinis IFO1125 was found to acquire increased aluminium (Al) resistance from 50 mu M to more than 5 mM by repetitive culturing with stepwise increases in Al concentration at pH 4.0. To investigate the mechanism underlying this novel phenomenon, wild-type and Al- resistant cells were compared. Neither cell type accumulated the free form of Al (Al3+) added to the medium. Transmission electron microscopic analyses revealed a greater number of mitochondria in resistant cells. The formation of small mitochondria with simplified cristae structures was observed in the wild-type strain grown in the presence of Al and in resistant cells grown in the absence of Al. Addition of Al to cells resulted in high mitochondrial membrane potential and concomitant generation of reactive oxygen species (ROS). Exposure to Al also resulted in elevated levels of oxidized proteins and oxidized lipids. Addition of the antioxidants a-tocopherol and ascorbic acid alleviated the Al toxicity, suggesting that ROS generation is the main cause of Al toxicity. Differential display analysis indicated upregulation of mitochondrial genes in the resistant cells. Resistant cells were found to have 2.5- to 3-fold more mitochondrial DNA (mtDNA) than the wild-type strain. Analysis of tricarboxylic acid cycle and respiratory-chain enzyme activities in wild-type and resistant cells revealed significantly reduced cytochrome c oxidase activity and resultant high ROS production in the latter cells. Taken together, these data suggest that the adaptive increased resistance to Al stress in resistant cells resulted from an increased number of mitochondria and increased mtDNA content, as a compensatory response to reduced respiratory activity caused by a deficiency in complex IV function.

DOI： 10.1099/mic.0.2007/016048-0

　前のページ - 次のページ　

1
2
3
4
5
6
7
8