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当前位置:首页 > 行业资料 > 交通运输 > 乙酰胆碱对黄化玉米幼苗物质跨节运输的调控效应
UDCModulatingeffectsofacetylcholineonmaterialtranslocationacrossnodeinetiolatedZeamaysseedlingsChinaAgriculturalUniversityPh.D.DissertationModulatingeffectsofacetylcholineonmaterialtranslocationacrossnodeinetiolatedzeamaysseedlingsPh.D.Candidate:PingLanSupervisor:ProfessorChenghouLouSpeciality:PlantScienceResearchfield:MaterialtranslocationandsignaltransductioninhigherplantJune,20011122363.163.263.2.163.2.26474.174.274.2.174.2.284.2.384.394.3.194.3.2104.3.3115126137138159151171.1171.2171.3172172.1172.2182.3183181251.1251.2251.3252262.1262.2CF272.3ACh273283.1283.2ACh281301.1301.2H+-ATPase301.2.1301.2.2311.2.3H+-ATPase311.2.4311.2.4.1311.2.4.2321.2.4.3321.2.5ATPase322322.1322.2SDS-PAGEH+-ATPase332.3H+-ATPase342.4ATPase343353.1353.2H+-ATPase351411.1411.2AChE411.2.1411.2.2411.2.3421.3AChE422422.1422.2432.3433431481.1481.2491.2.1491.2.2491.2.2.1491.2.2.2nAChR492502.1502.250350III-H+-ATPaseATPase0.1mmol/LH+-ATPaseH+H+H+-ATPaseIVH+-ATPaseH+-ATPaseH+-ATPaseH+-ATPase63.4%H+-ATPase100KD12H+-ATPase34NH+-ATPVAbstractForsurvival,higherplantsonlandmustovercomeallkindsofenvironmentalstresses.Toachievethisend,theplantmustactasawholethroughmaterialtransportandinformationtransmissionamongitsconstituentparts.Itistheplasmodesmata,theintercellularprotoplasmicbridge,thatlaysthefoundationofsymplasmicnet-workofcomunicationamongthevariouspartsofthewholeplant.Thepermeabilityoftheplasmodesmata(ortheeaseofcommunication),moreover,isregulatedbyseveralendogenousandexogenousfactors.Acetylcholine(ACh)istheforemostneuro-transmitterinanimals.Itisassistedbymembersofthecholingericsysteminperformanceofelectro-chemicalwavetransmissionattheneuro-muscularjunction.IthasbeenfoundthatbothAChandmembersofthecholinergicsystemarealsoofwideoccurrenceintheplantkingdom.WhilesomeofthephysiologicalprocessesregulatedbyAChinplantscanbeascribedtoitsactiononpermeabilityofthecellmembrane,AChisalsoeffectiveinregulatingintercellularmaterialtransportandsignaltransmission.Thepresentinvestigationalongthislineemployed4-dayoldetiolatedmaizeseedling(Zeamays)asexperimentalmaterial.Itselongatedshootisinterceptedbythenodeintotworegions:theuppercoleoptileandthelowermesocotyl(fig.1).Thecellsconstitutingthemesocotylweremostlycylindricalinsizeandarrangedmoreorlessparalleltothelongaxis;whereasthoseinthenodewereshorterinlengtharrangedirregularlyandricherinprotoplasmiccontent.Theproblemsunderinvestigationandtheirresultsaresummarizedasfollows:1,ComparisonofthepermeabilityandmaterialtransportatthenodeandthoseatthemesocotylbeforeandafterAChtreatment,asdeterminedbyelectricalresistancemeasurementandbydetectingdistributionofthefluorescentprobe(CF,carboxyfluoerescein)previouslyfedattheendoftheetiolatedcoleoptile.Specificelectricalresistanceacrossthenodewashigherthanthatacrossthemesocotyl.Consequently,shortnodalcellswithlowerintercellularpermeabilityretainedmoreCFthanthatthecylindricalmesocotylcells.0.1mmol/LAChtreatmentcouldincreasethepermeabilityofbothnodeandmesocotylthuspromotinghigherrateofCFtransportthanthatofcontrol.Variationinmaterialtransportacrossthenodeandthemesocotyl,aswellasitsmodulationbyAChtreatment,canbelargelyattributedtodifferencesintheirintercellularpermeability.2,EffectofAChonH+-ATPaseactivityoftheplasmamembrane,asdeterminedbybiochemicalanalysisandtransmissionelectronmicroscopy.Purifiedplasmamembranevesicleswereobtainedfrometiolatedcornseedlingsbysucrosegradientcentrifugationmethods,westernblottingshowedthatonebandonSDS-PAGEcanberecognizedbypolyclonalantibodyagainstVIPMH+-ATPase,itsmolecularweightwas100KD.TheactivityofPMH+-ATPasewasincreasedafterAChtreatment.3,Detectionandlocalizationofacetylcholinesterase(AChE)incellsatnode,asdeterminedbybiochemicalanalysisandtransmissionelectronmicroscopy.TheactivityofAChEwashigherinnodethaninmesocotylandcoleoptile.UltrastructurallocalizationofAChEinnodemesocotylandcoleoptilewascarriedoutusingKarnovskyandRoot’scytochemicalmethod.AChEofnodecellwasmailyinthenucleus,whileAChEwasinthecellwallandoutsideoftheplasmamembraneinthemesocotylandcoleoptile.ItisassumedthatAChEfrommesocotylandcoleoptilemayparticipateinthematerialtanslocationandsignaltransductionregulationbyhydrolysisingACh,howeverAChEfromnodemaybeinvolvedinthecelldedifferentiationandreorganization.Localizationofnicotinic-ACh-receptor(nAChR),asdeterminedbyFITClabeled-bungarotoxin.ThenAChRwasmainlydistributedonthesurfaceofprotoplastsfrometiolatedcornseedlingsbyFITClabeled-bungarotoxin.KeywordsetiolatedZeamays,acetylcholine,plasmamembraneH+-ATPase,acetylcholinesterase,nAChR,signaltransductionVIIAbbreviation’1Ruan2001Lou19981.1223Ünch1976GunningRobardsmRNADNARNADing19923nm8-10nm2.5nmSizeExclusionimitSELSEL800-1000Dalton0.7-0.8nmTilney1991Onocleasensibilis3TritonX-ATPaseTaizJones1973gapjunctionMeiners1987SELCplasmodesmatalassociatedproteins,PAPsMonerKloth199128KD43KDYahalom1991Connexin32Connexin43ConnexinsConnexin32Mr27KDaPAP27Connexin43Mr26KDaPAP26PAP26PAP27PAP26orficePAP27Yahalom1991199332KD50KD62KDZhang1990DGDWhite1994ActinOverall1996C
本文标题:乙酰胆碱对黄化玉米幼苗物质跨节运输的调控效应
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