Identification and characterization of structural proteins of orchid fleck virus

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

Orchid Fleck Virus: Brevipalpus californicus Mite Transmission, Biological Properties and Genome Structure

Orchid fleck virus (OFV) causes necrotic or chlorotic ring spots and fleck symptoms in many orchid species world-wide. The virus has non-enveloped, bacilliform particles of about 40 nm × 100–150 nm and is sap-transmissible to several plant species. OFV is transmitted by the mite Brevipalpus californicus (Banks) in a persistent manner and efficiently transmitted by both adults and nymphs, but not by larvae. Viruliferous mites retain their infectivity for 3 weeks on a virus-immune host. The genome of OFV consists of two molecules of 6431 (RNA1) and 6001 nucleotides (RNA2). The RNAs have conserved and complementary terminal sequences. RNA1 contains five open reading frames (ORF), and RNA2 encodes a single ORF. Although some of the encoded proteins of OFV have sequences similar to those of proteins of plant rhabdoviruses, OFV differs from viruses in the family Rhabdoviridae in having a bipartite genome

エビネから分離されたインゲンマメ黄斑モザイクウイルスの諸性質

Bean yellow mosaic virus (BYMV) was isolated from Calanthe sp.showing mild chlorosis on the leaves, collected in Yamaguchi Prefecture in Japan. The virus was transmitted by the aphid Myzus persicae in a non-persistent manner, and by sap-inoculation to 29 out of 46 plant species from 9 out of 12 families tested. Stability in crude sap, morphology of virus particles, shape of cylidrical inclusions and the presence of cytoplasmic crystalline inclusions in the infected cells were similar to those of BYMV isolates previously reported. The virus contained a single protein species with a molecular weight of 35,000. In a microprecipition test and double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), the virus showed a close serological relationship to isolates of BYMV from both crocus and gladiolus, and showed a distant relationship to clover yellow vein virus. Three BYMV isolates used in this study were found to be serologically related to each other, but the virus was more closely related to the BYMV crocus isolate than to gladiolus isolate.山口県で採集した葉にモザイク症状を示すエビネからインゲンマメ黄斑モザイクウイルス（BYMV）が分離された。本ウイルスは汁液接種により試験した12科46種のうち9科29種に感染し、モモアカアブラムシにより非永続的に伝搬された。本ウイルスの粗汁液中での安定性、粒子の形態、管状封入体及び細胞内結晶状封入体の形態は既報のBYMVのそれらと同様であった。SDS-PAGEによる外被タンパク質の分子量は35,000であった。微沈降反応及びDAS-ELISAにおいて、本ウイルスはクロッカス及びグラジョラスから分離されたBYMVと血清学的に近縁であったが、グラジョラス分離株よりもクロッカス分離株の方が本ウイルスとより近縁であった

Modeling and Flight Data Analysis of Spacecraft Dynamics with a Large Solar Array Paddle

The Advanced Land Observing Satellite (ALOS) was launched on January 24 2006 and has been operated successfully since then. This satellite has the attitude dynamics characterized by three large flexible structures, four large moving components, and stringent attitude/pointing stability requirements. In particular, it has one of the largest solar array paddles. Presented in this paper are flight data analyses and modeling of spacecraft attitude motion induced by the large solar array paddle. On orbit attitude dynamics was first characterized and summarized. These characteristic motions associated with the solar array paddle were identified and assessed. These motions are thermally induced motion, the pitch excitation by the paddle drive, and the role excitation. The thermally induced motion and the pitch excitation by the paddle drive were modeled and simulated to verify the mechanics of the motions. The control law updates implemented to mitigate the attitude vibrations are also reported

Detection of the Viruses Occurring in Oriental Cymbidium in Japan

A survey of virus diseases occurring in Oriental Cymbidium collected from a commerical nursery and home garden in Japan was conducted in 1991-1994. Identification of the vurus was based on partcle morphology, symptomatology in indicator plants, ultrastructure of infected cells and serology. Four viruses, odontoglossum ringspot tabamovirus(ORSV), cymbidium mosaic potexvirus(CyMV), orchid fleck virus (ORV) and a previously underscribed spherical virus, were found in 27 out of 37 Cymbidium plants tested. ORSV was detected from 11 plants belinging to Cym. ensifolium, Cym. forrestii, Cym. goeringii, Cym. kanran, Cym. sinense and Cymbidium spp. showing chlorotic streaks and/or mild mosaic. CyMV was isolated from only one plant of Cymbidium sp. showing mosaic and necrotic spots on leaves. In negatibvely stained dip preparations from plants infected with ORSV and CyMV, rod shaped particles of ca. 310 nm and flexuous rod-shaped ca. 475 nm in length were observed, respectively. The viruses were reacted strongly with respective antiserum to each virus in immunosorbent electron microcopy and inderect ELISA. OFV was isolated from four plants of Cym. formosanum, Cym. kanran, Cym. sinense and Cymbidium sp. showing mosaic and necrotic flecks. The virus had non-enveloped, bullet-shaped particles about 40×120～150 nm in dip preparation. The undescribed spherical virus, ca. 28 nm diameter, was isolated from 11 plants of Cym. forrestii, Cym. goeringii and Cymbidium spp. showing stunting and chlorotic streaks on newly developed leaves. The virus was mechanically transmitted only to Cymbidium orchids. Previously, we designated it as cymbidium chlorotic mosaic sobemovirus(CyCMV)(Kondo et al,1994),as the virus was considered to be a new member of the genus Sobemovirsu.1991～1994年にかけ山口県ならびに岡山県下を中心に東洋ラン（シンビジウム属）のウイルス病の発生調査を行った。ウイルス病様の症状を示していた37株の東洋ランを採集し、これらから病原ウイルスの分離、同定を試みた結果、オドントグロッサムリングスポットウイルス（ORSV）、シンビジウムモザイクウイルス（CyMV）、ランえそ斑紋ウイルス（OFV）ならびにソベモウイルス属の新ウイルスであるシュンラン退緑ウイルス（CyCMV）の発生が認められた。ORSVは退緑条斑や軽いモザイク症状を示すスルガラン、カンラン、コラン、ホウサイランなどから分離された。CyMVは明瞭なえそ斑を伴うモザイクを呈した東洋ラン（品種不祥、赤芽素心）から分離された。ORSVならびにCyMVに感染した植物のDN法試料中には電顕観察でそれぞれ長さ約310nmの棒状粒子と約475nmのひも状粒子が観察され、免疫電顕法と間接ELISA法では、これらのウイルスはそれぞれのウイルスに対する抗血清とよく反応した。OFVは退緑斑あるいはえそ斑点を生じているイトラン、カンラン、ホウサイランなどから検出された。その粒子形態は長さ約120～150nm、幅約40nmの被膜のない弾丸状あるいは桿菌状であった。CyCMVは新芽に明瞭な退緑斑や退緑状斑症状を示すシナシュンラン、シュンランなどから分離された。この球状ウイルスは直径約28nmで、シンビジウム属以外の植物には感染が認められなかった。今回の発生調査では、東洋ランからはORSVならびに新ウイルスのCyCMVがもっとも多く分離され、OFVは4株から、CyMVは1株から検出された。またこれらのウイルスによる重複感染は認められなかった

Close Relationship between Serotype and Pathogenicity of Cucumber Mosaic Virus

Sixty-eight isolates of cucumber mosaic virus (CMV) belonging to the Y serotype (serogroup) or P serotype (serotype Ⅱ)　in Japan were inoculated to Nicotiana tabacum cv. White Burley and the symptoms were observed up to three months after inoculation. These isolates were divided into four goups accoding to symptomatology on tabacco plant. None of the isoletes obtained from lilies infected tobacco plants systemically. The plants inoculated with isolates of the P serotype showed systemic mosaic, but only occasional mild symptoms were observed on newly developed leaves. On the other hand, all isolates of Y serotype showed symptoms consisting of mosaic, distortion and/or necrosis throughout the experimental period. In another experiment, reactions of some selected test plants to 30 isolates belonging to the Y or P serotype were examined. Lily isolates may be unique strain of CMV as they did not cause systemic infections on Lycopersicon esculentum, Solanum melongena or Cucumis sativus. Host range tests using 16 isolates originally obtained from plants other than lilies demonstrated a close relationship between serotype and pathogenicity to some test plants including N.tabacum, N. clevelandii, L.esculentum, Pisum sativum, phaseolus angularis and Zea mays.日本で分離されたキュウリモザイクウイルス（CMV）のY血清型あるいはP血清型に属する68分離株をタバコに汁液接種した結果、それらは病徴から4つのタイプに類別することができた。それらのうち、ユリからの14分離株はタバコには全身感染しなかった。タバコに全身感染する分離株のうち、Y血清型のすべての分離株は接種後長期間経過しても、新葉にモザイク、えそ、奇形などの病徴が常に認められたが、P型では接種後の日数が経過すると新しく展開した葉には病徴が認められないことが多かった。また、CMVのそれぞれの血清型の分離株を各種植物に接種し、宿主範囲および病徴を調べた結果、ユリからの分離株はタバコ、トマトなどのナス科植物やキュウリなどに全身感染しない点で、これまでに報告されている多くの系統とは異なっていた。また、ユリ以外の植物から得られた分離株では、数種のナス科植物、エンドウ、アズキ、トウモロコシなどにおいて、血清型と病原性との間に明確な関連が認められた