SignalInductionDetermined:Competent:Expressed:Able tofollow sameAble to respond inThe apicaldevelopmentalexpectedmannermeristemwhen given thePhotoperiod program even after Hormones?undergoesremoval from itsappropriatemorphogenesis.developmentalnormal position insignals.plant.FlowersVegetative growthFigure 11-1Asimplifiedmodelforfloralevocationattherespondtoafloralstimulus(induction)bybecomingfloshootapexinwhichthecellsofthevegetativemeristemrallydetermined(committedtoproducinga flower).Theacquirenewdevelopmentalfates.Tinitiatefloraldevelodeterminedstateisusuallyexpressedbutthismayrequiran additional signal.(After McDaniel et al.1992)mnhelsfthmistemmutfirsommtentAcompeentvegetativemeristemisonethatcan
Figure 11-1
(leavesSDPSDP(TipSDP(leaves)LDP(plant)DB4Fig. 11-3
Fig. 11-3
16L-8D15L-9D16L-8D,一个光诱导周期（15L-9D)16L-8D安正Fig.11-5DBC1
Fig.11-5
LightPhotoperiodismLeafLowSucroseGibberellinsnumbertemperatureBlueRedFarredGAreceptorCRY1PHYBPHYACRY21VernalizationYCLOCKGENESAutonomousEnergyGibberellinpathwaypathwaypathway"Florigen"(phloem)FLOWERINGLOCUSCinhibitsfloweringAGAMOUS-LIKE20CONSTANSMeristemidentity genesLEAFYFIGURE24.32Fourdevelopmentalpath-Figure 11-7waysforflowering inArabidopsis:thephotoperiodism,autonomous/vernalization,sucrose,andgibberellinpathways.Atransmissiblefloralstimulus("flori-AP1AP2HAGFloralgen)fromleavesis onlyinvolved inthehomeoticphotoperiodicpathway.(AfterBlazquezAP3,PIgenes2000.)SepalsPetalsStamensCarpelsFloral organs
Figure 11-7
Interpretationof thephe-(A)WildtypenotypesoffloralhomeoticmutantsbasedontheABCmodel.(A)Wildtype.(B)Lossof CfunctionresultsinWhorl234expansionof theAfunction throughoutthe floral meristem.(C) Loss of A func-88Btion results in the spread of C functionGenesthroughout the meristem. (D) Loss of BACfunctionresultsintheexpressionofSepalPetalStructureStamenCarpelonlyA and Cfunctions.(B)LossofCfunctionWhorl2431BGenesASepalPetalPetalSepalStructure(C)LossofAfunction23Whorl4BGenesCCarpelStructureCarpelStamenStamenFig.11-8(D)LossofBfunction2Whorl341GenesAcStructureSepalSepalCarpelCarpel
Fig.11-8 Fig.11-8