ANDO  Sugihiro

IKEGAMI  Masato

TAKAHASHI  Hideki

English

application/pdf紀要類 (bulletin)1660995 bytesdepartmental bulletin pape

IKEGAMI, Masato

TAKAHASHI, Hideki

ANDO, Sugihiro

Tohoku University Repository (TOUR) / 東北大学機関リポジトリ

Recent Research Topics in the Laboratory ofPlant Pathology著者 IKEGAMI  Masato, TAKAHASHI  Hideki, ANDO Sugihirojournal orpublication titleTohoku journal of agricultural researchvolume 60number 1-2page range 45-50year 2009-12URL http://hdl.handle.net/10097/41178Tohoku Joumal of AgriculturalR朗earChVol. 60 Ⅳ0. 1-2, December 2009Pn'nted in JapanRecent Research Topics in the Laboratory ofPlant Patholo色yMaBatO IKEGAMI, Ⅱidek-1 TAKAHASHI and Sugihiro ANDOD甲artment Of Lqe Schnoe, Graduate Schwl of Agrhltural Sbienee,Tohoku University, Sendai, Japan(Received, September 2, 2009)Summaryln our Laboratx'ry, mainly two different projects de8Cribed below払e nowcamied out･. (1) Molecular plant pathologiCalstudies on geminiviruses (2) Mech-anism for t･he resistance to cucumber mosaic virus (CMV) in Arabidqpsis thalianaatthe molecular level The results obtained from ea血project are followings. (1)The genome organizations of begomoviruses from Far East Asian countries weredetxBrmined. The βCl gene encoded by I)NAβ satxtllite was RNA silencing sup-pressor and induced the symptx)ms. Sabllite DNAp associatedwithFar EastAsianbegomoviruses enhanced the pathogenicity of tomato yellow leaf curlbegomoviruS (TYLCV) i8018tXtd in Japan. The transgenic N. bmthamiana plant8expressing GroEL protein was transgenLC Plants was tolerant to TYLCV. Theplants expresslng GroEL werealSo tolerant to CMV that binds to GroEL in vi的.(2) This resistance to CMV(Y) in A. thaliana ecot･ype C24 was conferred by aSingle dominant gene ROYl encoding CCINBILRR type protein. Mutationalmalysis of three domainsinRCYI protein indicatedthat CC, NB and LRRdomains aJ.e required for reSt･riction of virus SPread but differentially impa加theinduction of HR-like cell death･ Furthe-ore, constitutive accumul乱tion of high1evels of RCYI protein appeared to reguhtethe strengthof ROYl-conferredresistance in a gene-for-gene manner.Molecular Plant Patholo色icalStudies on GemimivirusesMolecular Breeding of Multi TlimbSeS-tolerant PlantsTransgenesis offers many ways to obtain virus-resistant plants. However, lnmost cases resistanOe is against a single virus or viralstrain. We have taken anovel approach based onthe ability of a whitefly endosymbiotic GroEL to bindviruses belonging to severalgenera, in vivo and in vitro. We have expressedtheGroEL gene in Nicotiana benthamiana plants, postulating that upon virus inocu-lation, GroELwill bind to viruses, thereby interfering withpathogenesis. Thetransgenic plants were inoculatedwiththe begomovirus tomato yellow leaf curl4546 M･ Zkegami et al.virus (TYLCV)andthe cucumovirus cucumber mosaic virus (CMV), both ofwhich interactedwith GroEL in m'tro, andwith the trichovirus grapevine virus A(OVA) and the tobamovirus tobacco mosaic virus (TMV), which did not.Whilethe transgenlC Plants inoculated withTYLCV and CMV presented a highlevel oftolerance, those inoculated with GVAand TMV were susceptible･ This studydemonstrated that multiple resistances･ to viruses belonglng tO SeVeraldifferenttaxonomic genera could be achieved.Interaction of Tomato Yellow Leaf Curl Virus with Betasatellites EnhancesSymptom SeventyWe previously reportedthat tobacco leaf curl JapanviruS (TbLCJV) andhoneysuckle yellow vein mosaic virus (HYVMV)with satellite DNAβ are causalagents of tomato yellow dwarf disease in Japan,and honeysuckle acts as apotential reservoir host (Ogawa e't all, 2008)･ HmV and TbLCJV have hybridgenomes, which are likely to have formed recombination between HmVandTbLCJV (Ogawa et al., 2008).Tomato yellow leaf curl disease is a very aoute problem for tomato cultivationin Japan･ Tomato yellow leaf curl virus (TYLCV) was identified as a oausalagent of this disease･ We investigated the interaction of TYLCV withtwoknown satellites associatedwith tomato yellow dwarf disease in Japan, tx)baccoleaf curl Japanbetasatellite [Japan : Ibaraki : 2006]and honeysuckle yellowvein mosaic betasatellite [Japan : Nara : 2006], as well as withtomato leaf curlPhilippines betasatellite [Philippines : Lagunal : 2008] in tomato and Nicotianabenthamiana plants･ TYLCV trans-replicated these betasatellites, inducing moresevere tomato yellow leaf curl disease-related symptoms than TYLCValone (Ito¢£ α～., 2009).乃β Gbne Function of βCI Gene of Satellite DNAβ of the Begommn'nLS TomatoLeaf Curl tTava Virus ; Suppressor of RNA Silencing Encoded by its GeneWe previously isolatedthe monopartite begomovirus tomato leaf curl Javavirus (ToLCJAV) and satellite I)NAβ02 from the same naturally infected tomatosource in lndonesia･ ToLCJAV inducedmild leaf curl symptoms in Niootianabenthamiana plant芯; I)NAβ02 encoded the βCl gene and produced severe leafcurl symptoms when co-inoculatedwith ToLCJAV in N. benthamiana. IIow_ever, I)NAβ02mPCl, which contains a frame shift mutation, did not induce severesymptoⅡ鳩in N benthamiana when co-inoculatedwith ToLCJAV･ Expression ofthe βCl gene in N･ benthamiana using a potato virus X (PVX) vector inducedvirus-like symptoms in the absence of ToLCJAV infection･When βCland gremPuorescent protein (GFP) genes were co-expressed in the GFP-expressing N.benthamiana line 16c from a PVX vector, βCI was able to suppress posttransIcriptionalgene silencing (PTGS) induced by GFPand eliminated the shortRecent Reseaqy:h Topics in the Laboratory of Plant Pathology　　47interfering RNA (siRNA) associatedwith Gyp expression,with a correlatedincrease in GFP mRNA accumulation (Ron et al･, 2007)･When C2 or 04 genesof ToLCJAV and the Gyp gene were co-expressed in the GFP-expresslng N･bmthamiana line 160, C2 showed a week suppressor activityand C4 wasunableto suppress PTGS induced by GFP, and siRNA a占SOCiatedwithGFP was detected(Ron et all, 2007)･ The results of the sub-cellular localization of ToLCJAV-βClin the epidemal cells of N. benthamiana and onion tissues showedthatthisprotein is accllmulated towardsthe periphery of the cell･Molecular Mechanism for RCYl-Conferred Resistanceto Cucumber Mosaic Virus in ArabidopsisCucumber mosaic virps (CMV) is tripartite positive-sense学.ngle-StrandedRNA virus and has a widest host range in any other viruses･ Arabidopsis thalianaecotype C24 is resistant to an yellow strain of CMV [CMV(Y)] but susceptible toan Indonesian strain of CMV [CMV(B2)] , whereas A. thaliana ecotype Columbia(Col-0) is systemically infected by both strains. The resistance to CMV(Y) inC24 is conferred by a single dominant gene RCYl encoding CCINB-LRR typeprotein containing coiled-coil (cc), nucleotide-binding (NB) and leucine-richrepeat (LRR) domains and accompanied by the development of necrotic locallesions (NLLs) atthe primary infection sitxt, elevated expression of thepathogenesis-related la (PRla) gene and accumulation of salicylic acid (SA)(Ishihara et al., 2008 ; Taknhashi et al., 2005).Mutational Analysis of cc, NB and LRR Domains in RCYI ProteinThe resistance to CMV(Y) was compromised in RCYl-silenced C24, whereasRCY1-transformed Col-0 exhibit冶d resistanoe to CMV(Y), demonstrating thatRCYl govems the resistance to CMV(Y) in C24 (Sekine et al., 2008). Tocharacterize the role of RCYl in the resistance to CMV(Y) and NLL fomation, weidentified six recessive CMV(Y)-susceptible rcyl mutants, four of which containslngle amino acid substitutions in RCYl : rcy1-2 contains a I) to N substitutionin the CC domain, rcy1-3 and rcy1-4 contain R tx) K and E to K substitlltions,respectively, in the LRR domain, and rcy1-6 contains a W to C substitution in theNB domain (Sekine et al･, 2006)･ The rcy1-5 and rcy1-7 contain nonsensemutations in the LRR and NB domains, respectively. Althoughthe virussystemiCal1y spread inall six nyl mutants, hypersensitive response (HR)-associated cell death was differentially induced in these nutants･ TranS-complementation was observed between the rcy1-2 and rcy1-4al1eles ; in FIplants derived from a cross between rcy1-2 and rcy1-4, IIR-aBSOCialxBd cell deathwas accelerated and systemic spread of the virus was partially suppressed than inthe homozygous rcy1-2 and rcy1-4 plants･ These results suggest that the CC, NB48 M･ Lkegami et al.and LRR domains of RCYl are required for restriction of virus spread butdifferentially impact the induction of HRllike cell death and the inter-molecularinteraction of RCYl may involves inthe resistance to CMV(Y) in Arabidopsis.Resistance to OMV(Y) Depending on the Accumulated Level of RCYI ProteinTo further study RCYl-conferre4 resistance to CMV(Y), A. thaliana ecotypeCol-0, which is susceptible to CMV(Y), were transfo-edwith RCYl. Systemiospread of CMV(Y) was completxtly suppressed in five independent lines ofRCYl-transformed Col-0 (Col : : pRCYl lines 2 to 6), whereas Virulent strainCMV(B2) spread and multiplied systemically in these transgenic lines similar tothat inwi1d-type Col-0 (Sekine et al･, 2008). Interestingly,the resistantphenotype of Col : : PRCYI varied among the lines･ In lines 3 and 6, in whichlevels of RCYl transcript were similar to that inwild-type C24, the HR andres_igtanCe tO CMV(Y) was indu'ced･ Line 4, which expresses moderately elevatedlevels of RCYl transcript, exhibited moderatxtly enhanced resistance comparedwith that in C24 or line 3･ In contrast, lines 2and 5, which highly over-expressthe ROYl gene, did not exhibit either visible lesions or amicro-HR on theinoculated leaves･ Moreover, virus coat prot冶in was not detected in eitherinoculated or non-inoculated upper leaves of these two lines, suggesting thatextreme resistance (ER) to CMV(Y) W舶induced by high1evels of expression ofROYl･ Furthermore, in transgenic lines expressing hemagglutinin (HA) epitope-tagged RCYl (Col : : pRCYl-IIA), high1evels of accumulation of RCYl-HAprotein werealso correlatedwith the ER phenotype･ Thus, oonstitutive accumu-lation of highlevels of RCYI protein appears to regulate the strengthof RCY1-00nferred resistance in a gene-for-gene manner and implies that ER and HR-associated resistance differ only inthe strength of resistance･Reference sIshihaJa, T･, Sekine, K･-T･, Ease, S･, Kanayama, Y., Seo, S., Ohashi, Y., Kusano,T･･ Shibata, D･, Shah, J･ and Takahashi, H･, Overexpression of theArabi'dqpsis thaliana EDS5 gene enhances resistance to viruses.Plant Bゐl., 10, 451-461 (2008)Ito･ T･, Kimbara, J･, Sharma, P･ and Ikegami, A4･, Intcraction of tomato yellowleaf curl viruSwith betasatellites enhances symptx)m severity･ ArchYirol･, 154, 1233-1239 (2009)Kon･ T･, Sharna, P･ and Ikegami･ M･, Suppressor of RNA silenclng encoded bythe monopartite tomato leaf curl Java begomoviruS･ Arch･ Virol.,152, 1273-1282 (2007)Ogawa, T･, Sh乱-a･ P･ and Ikegami･ M･, The begomoviruses Hmwysuckleyelhnpvein mosaic m'ns and Tobaccoleaf curl Japan w'rwswith I)NAβsatellites cause yellow dwarf disease Of tDmatOI VL'nbS Research, 137,235-244 (2008)Sekine, K･-T･, Ishihi-, T･, Hase, S･, Kusan0, T･, Shah, J･ and Takahashi, H.,Recmt Resewch Topics in the Laboratory of Plant PathologySingle amino acidalt冶rations in Arabidqpsis thaliana RCYI compro-mise resistance to CtLmmber mosaic vins, but differentially suppresshypersensitive response-like cell death. Plant Mol･ Bゐlり62, 6691682 (2006)Sekine, K.-TりKawakami, S., Kubota, M., Ichinose, Y., Shah, J., Rang, HIGリKlessig, D.F. and Takahashi, II" High1evel expression of a virusresistance gene, RCYl, Confers extreme resistance to CuczLmbermosaic m'rus in Arabidqpsis thaliana. Mol. Plant-Microbe Interact.,21, 1398-1407 (2008)Sharma, P. and lkegami, M., Tomatoled curl Java vimLS V2 protein is adeterminant of virulence, hypersensitive re8POnSeand suppression ofpost transcriptionalgene silencing･ Vb'rology doi : 10･ 1016/j･virol･2009.10.012 (2009)Tal(ahashi, I., Sekine, K.-T., Ishihara, TりIIase, S., Ikegami, M. and Shah, J.,"Signal transduction pathways for the resistance response to Cwum-ber mosaic virulS." Genomic and GmetゐAnalysis of Plant Par-asilism and ･Defense. In 9th Japan-USA Scientific Seminar (Eds･ S･Tsuyumu, J.Leach, T. Shiraishi and T. Walpert), APS Press, StPaul, Minnesota, USA, pp 185-194 (2005)49

Recent Research Topics in the Laboratory of Plant Pathology

https://tohoku.repo.nii.ac.jp/?action=repository_action_common_download&item_id=65571&item_no=1&attribute_id=18&file_no=1

Recent Research Topics in the Laboratory of Plant Pathology

Abstract

Similar works

Full text

Available Versions

Tohoku University Repository (TOUR) / 東北大学機関リポジトリ