植物生物钟课件

©2016AmericanSocietyofPlantBiologistsRhythmsofLife:ThePlantCircadianClockSomers,D.E.(1999).Thephysiologyandmolecularbasesoftheplantcircadianclock.PlantPhysiol.121:9-20.©2016AmericanSocietyofPlantBiologistsLivingonarotatingplanetisbiologicallystressfulOvera24hourperiodthereislargevariationinenvironmentalconditionsincludingtemperature,lightintensity,humidityandpredatorbehaviorSeeKudoh,H.(2016).Molecularphenologyinplants:innaturasystemsbiologyforthecomprehensiveunderstandingofseasonalresponsesundernaturalenvironments.NewPhytol.210:399-412.Image:NASA.•Extremeday-nighttemperaturedifference:57oC(-48oCto9oC,Montana,1972)•Typicalday-nightfluctuation:~10oCeachday(centralJapan)©2016AmericanSocietyofPlantBiologistsCircadianclocksarebiologicaloscillatorswitha~24hourperiodLight-DarkcyclesContinuousdarkness-Higherlevelsofwheelrunningactivityatnight-Incontinuousdarknesstheserhythmspersistbutwitha~23hourperiodFigurefromLi,J.-D.,Burton,K.J.,Zhang,C.,Hu,S.-B.andZhou,Q.-Y.(2009).VasopressinreceptorV1aregulatescircadianrhythmsoflocomotoractivityandexpressionofclock-controlledgenesinthesuprachiasmaticnuclei.Am.J.Physiol.296:R824-R830,usedwithpermission.Imagesource:Mylius.InactiveActive©2016AmericanSocietyofPlantBiologistsCircadianclockscontrolmanyaspectsofhumanphysiologyImagesource:Addicted0422.30BowelmovementssuppressedDeepestsleep21.00Melatoninsecretionstarts19.00Highestbodytemperature17.00Greatestmusclestrength15.30Fastestreactiontime14.30Bestcoordination06.45Riseinbloodpressure04.30Lowestbodytemperature02.00DeepestsleepMelatoninsecretionstops07.30Highalertness10.0018.30Highestbloodpressure©2016AmericanSocietyofPlantBiologistsPlantcircadianbiologyhasalonghistoryIllustrationof‘sleep’movementsinMedicago,fromCharlesDarwin(1880)‘ThePowerofMovementinPlants’Imagesources:H.Zell,CharlesDarwin“PowerofMovementinPlants”DeMarian(1729)‘Observationbotanique’ofMimosapudica:“sensitivetotheSunanddaylight:theleaves&theirpedunclesfoldthemselvesaway&contractaroundsunset,inthesamewaytheydowhenthePlantistouchedorshaken.”©2016AmericanSocietyofPlantBiologistsArchitectureofthecircadianclock©2016AmericanSocietyofPlantBiologistsPrinciplesofoperationofplantcircadianclocksAspectoftheCircadianSystemBiologicalFunctionCircadianoscillatorGeneratearhythmwitha~24hperiodwithinthecellEntrainmentpathwaysSynchronizetheoscillatorwiththeexternaltimeofdaysothattheclockstaysaccurateOutputpathwaysCommunicatetemporalinformationfromtheoscillatortootherpartsofthecellCircadiangatingAdjustthesensitivityofentrainmentandoutputpathwaysdependingonthetimeofday©2016AmericanSocietyofPlantBiologistsInterconnectedpartsofthecircadiansystemCircadianoscillatorEntrainmentpathwaysOutputpathwaysGeneRhythmsin:-transcription-physiology-biochemistryEnvironmentalInputsCircadiangatingofentrainmentandoutputs©2016AmericanSocietyofPlantBiologistsThecircadianoscillatorMostcircadianclocksaretranscription-translationfeedbackloopsGeneAGeneBProteinATheproteinencodedbyGeneAactivatesGeneBProteinBTheproteinencodedbyGeneBrepressesGeneA©2016AmericanSocietyofPlantBiologistsThecircadianoscillator•Reciprocalfeedbackloop•Negativefeedbackstep•SpeedofbiochemicalreactionsaddsarateconstantSimplebiologicaloscillator012243648GeneAGeneBProteinAProteinBGenetranscriptabundanceThefeedbackloopresultsinrhythmsoftranscriptabundanceofthetwogenesTime(hours)GeneAGeneB©2016AmericanSocietyofPlantBiologistsAnearlymodelforthefunctioningofthecircadianclockinArabidopsisFromAlabadı́,D.,Oyama,T.,Yanovsky,M.J.,Harmon,F.G.,Más,P.andKay,S.A.(2001).ReciprocalregulationbetweenTOC1andLHY/CCA1withintheArabidopsiscircadianclock.Science.293:880-883.ReprintedwithpermissionfromAAAS•Thisisoneofthefirststructuresproposedfortheplantcircadianclock•Itisanoscillatorwithactivationandsuppressionfeedback(comparewithpreviousslide)•ThemaingenesinvolvedareTOC1,LHYandCCA1•Themodelisoutofdate(TOC1actuallysuppressesCCA1),butprovidesanexampleofoscillatorstructureGeneAProteinAGeneBProteinBActivation(outofdate!)Suppression©2016AmericanSocietyofPlantBiologistsReciprocalrepressionbetweenCCA1andTOC1atthecoreofthecircadianclockFromAlabadı́,D.,Oyama,T.,Yanovsky,M.J.,Harmon,F.G.,Más,P.andKay,S.A.(2001).ReciprocalregulationbetweenTOC1andLHY/CCA1withintheArabidopsiscircadianclock.Science.293:880-883.ReprintedwithpermissionfromAAAS.Gendron,J.M.,Pruneda-Paz,J.L.,Doherty,C.J.,Gross,A.M.,Kang,S.E.andKay,S.A.(2012).Arabidopsiscircadianclockprotein,TOC1,isaDNA-bindingtranscriptionfactor.Proc.Natl.Acad.Sci.USA109:3167-3172.OverexpressionofCCA1suppressescircadianoscillationsofTOC1CCA1andLHYbindtothepromoterofTOC1OverexpressionofTOC1suppressescircadianoscillationsofCCA1TheCCTdomainofTOC1isrequiredforittobindtheCCA1promoter©2016AmericanSocietyofPlantBiologistsThecurrentmodelofthecircadianoscillatorisacomplexnetworkEveningComplexReprintedfromHsu,P.Y.andHarmer,S.L.(2014).Wheelswithinwheels:theplantcircadiansystem.TrendsPlantSci.19:240-249withpermissionfromElsevier..MorningLoopNoteTOC1isasuppressorofCCA1/LHY(comparewithpreviousmodel)©2016AmericanSocietyofPlantBiologistsDifferentclo