植物逆境信息传递研究进展

StressSignalinginPlants贾文锁中国农业大学 一 感知 和 反应 生物生存和发展的基础 敏感植物 一般植物 Rain Wind andTouch InducedExpressionofCalmodulinandCalmodulin RelatedGenesinArabidopsisCell60 357 364 1990 二 刺激 逆境 反应 应答 1 形态 解剖 ClusterRoots 2 整体生理 生命周期 短命菊 3 细胞生理及生化 1 解毒机制 2 自由基清除 3 区隔化机制 4 代谢调控 5 渗透调节 6 保水机制 7 结构避损机制 8 修复机制 渗透调节 脯氨酸甜菜碱山梨醇海藻糖 保护酶系统与自由基清楚剂游离的带有不成对电子的分子 原子或离子 区隔化机制 结构避损机制 功能蛋白代谢调控蛋白 渗透调控系统 保护酶 Lea蛋白 Late Embryogenesis AbundantProtein 通道蛋白 离子通道 水通道热击蛋白 亲水 保护酶活损伤修复蛋白调节蛋白信号蛋白转录因子 基因 功能蛋白基因调节蛋白基因 应答反应与伤害反应 三 信号系统与信号组分 CellularSinglingSystem 细胞信号系统 1Receptor Sensor2 SecondMessenger3 ProteinKinase4 ProteinPhosphatase5 G protein6 TranscriptionFactor7 Ubiquitination8 Methylation SignalComponents 1 Receptor Sensor Receptortyrosinekinase 细胞内受体 ExamplesofPhytohormoneReceporandSignalTransduction ABAReceptor BRI1isamembrane associatedreceptorthatcyclesbetweentheplasmamembraneandendosomalcompartments Theextracellularleucine richrepeatdomainbindsbrassinosteroidsandtransducesthesignalthroughanintracellularkinasedomain GTG1andGTG2areGPCR typeGproteinsthatbindabscisicacid TheyhaveinherentGTPaseactivitybutalsointeractwiththeonlycanonicalGsubunitinArabidopsis PYR1 RCAR1isasolubleABAreceptorthatrepressesPP2CphosphatasesinthepresenceofABA ThecytokininreceptorsCRE1 AHK2andAHK3areplasma membrane associatedandperceivecytokininthroughtheirextracellulardomains Cytokininbindingtriggersaphosphorylationcascadethatisultimatelytransmittedtoresponseregulatorsinthenucleus Likethecytokininreceptors theknownethylenereceptorsaretwo componentregulators AllfivereceptorsareactiveintheendoplasmicreticulumandtransmittheirsignalthroughacommondownstreamcomponentcalledCTR1 TIR1andCOI1areF boxproteinsthatareintegralcomponentsofSCF typeE3ligasesandrecognizetheplanthormonesauxinandjasmonicacidrespectively GID1isanuclear localizedreceptorforgibberellins GibberellinbindingtoGID1resultsintheenhanceddegradationDELLAproteins 自由基信号转导 3 ReversibleProteinPhosphorylaton 4 TranscriptionFactors 泛素 ubiquitin 是一种存在于大多数真核细胞中的小蛋白 它的主要功能是标记需要分解掉的蛋白质 使其被水解 当附有泛素的蛋白质移动到桶状的蛋白酶的时候 蛋白酶就会将该蛋白质水解 也可能被转移到细胞或细胞外的特定部位 也有可能导致靶蛋白的功能发生变化 泛素76个氨基酸组成 分子量大约8 5KD Ubiquitination 四 细胞逆境信息传递 举例介绍 盐胁迫和营养胁迫 离子通道的调节 Figure12 FreezingandDroughtToleranceofthe35S DREB1Aband35S DREB1AcTransgenicPlants Control 3 week oldplantsgrowingundernormalconditions freezingstress plantsexposedtoatemperatureof 6 Cfor2daysandreturnedto22 Cfor5days droughtstress waterwithheldfromplantsfor2weeks Percentagesofsurvivingplantsandnumbersofsurvivingplantspertotalnumberoftestedplantsareindicatedunderthephotographs wt wildtype HistoryofAbscisicAcid ABA In1963 abscisicacidwasfirstidentifiedandcharacterizedbyFrederickAddicottandhisassociates Theywerestudyingcompoundsresponsiblefortheabscissionoffruits cotton TwocompoundswereisolatedandcalledabscisinIandabscisinII AbscisinIIispresentlycalledabscisicacid ABA Addicot 1963 Twoothergroupsataboutthesametimediscoveredthesamecompound OnegroupheadedbyPhilipWareingwasstudyingbuddormancyinwoodyplants TheothergroupledbyVanSteveninckwasstudyingabscissionofflowersandfruitsfromlupine Plantphysiologistsagreedtocallthecompoundabscisicacid SalisburyandRoss 1992 SignalingFromWaterStressSensingtoABAAccumulation 五系统逆境信息传递 SystematicSignalinginPlantsorlong distancesignaling orintercellularsignaling RootToShootSignalingUnderWaterDeficitCondition pHSignaling Image2 PseduColorRatio imagesofpHindicatorBCECFinsunflowerstemandleafvascularsystempHindicatorBCECFwasloadedintothevascularsystemofanindividualsunflowerplantandimageswereacquiredasdescribedin MaterialandMethod A vascularsystematstembase B vascularsystematmidribofleafblade Image3 PseduColorRatio imagesShowingtheEffectoftranspirationrateonleafapoplasticpHofCommelinacommunisL pHindicatorNERFwasfirstloadedintointactplantthroughrootsystem thentheplantswereallowedtotranspirefor1hundereither35 or85 humidity followingwhichfluorescenceimageswereacquiredasdescribedin MaterialandMethod AandB transpirationat35 humidity CandD transpirationat85 humidity Image3 PseduColorRatio imagesShowingtheEffectoftranspirationrateonleafapoplasticpHofCommelinacommunisL pHindicatorNERFwasfirstloadedintointactplantthroughrootsystem thentheplantswereallowedtotranspirefor1hundereither35 or85 humidity followingwhichfluorescenceimageswereacquiredasdescribedin MaterialandMethod AandB transpirationat35 humidity CandD transpirationat85 humidity 干旱条件下ABA可以作为长距离传递信号使植物产生系统抗逆性 SystematicSignalingofLargeMolecularSignals Fig 3 Newmodelforthephotoperiodresponseinplants A ThepictureontheleftrepresentsthecurrentlyacceptedmodelforArabidopsis inwhichlight activatedCOovercomesthetemperature dependentinhibitionfromFLCandinducestheexpressionofFTinthephloemcompanioncells FTismovedtothephloemandchannelledtotheapicalmeristemwhereitbindstoFDandthecomplexisrecruitedintothenucleus FT FDbindstothepromoterofSOC1andothermeristematicfloralintegrators changingthevegetativedevelopmentalprogrammetotheABCprogramme eventuallyproducingflowers B ThemodelproposedhereincludesthatdepictedinA butalsorecruitssimilarphotoperiodicmechanismstoregulateotherdevelopmentalprogrammesandbasicphysiologicalprocesses Yellowarrowsrepresentexternalsignals