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
(A)(B)Vesicles containingMicrofilamentEndoplasmiccellwall precursorsreticulumCalloseplugs士一HSpermVegetativecellsnucleusMitochondrionExinewallIntine wallVesicle fusing with cellGolgimembrane at tube tipFigure19.29(A)Schematicillustrationofapollentubegrowingbytipextension.CalloseplugslimitthevolumeoccupiedbythecytoplasmtoregionsclosetothegrowFigure 11-9ingtip.(B)FluorescencemicrographofpollentubesgrowingthroughapistilThecalloseplugsthatblockoffthepollentubeatregularintervalsarevisual-ized by stainingwithanilineblue
Figure 11-9
Pollen grainPollentubePlasmamembraneIntinewallExinewallPollencoatproteinsMeniscusStigmaticpapillaPollen ligandPollen coat喜adhesionCmolecule杭SLR1SLG秀Figure19.33SLR1Thescanning electron micrograph at leftshows the surface of a stigma.Stigmatic7SRKSRKpapillae and pollen grains are visible.TheMODsimplified schematicrepresentation atrightStigma cellwater.channelillustrates the contact zonebetween a Brassicastigmaticpapillarcelland anincompatiblepollengrain.Someof theproteinsthoughttobeinvolved intheinteraction areshown (theshapes and sizes of the proteins inthis modelFigure 11-10arehypothetical).Slocusreceptorkinase(SRK)maybindthepollenligand,andinsome cases this binding might be facilitatedby interactionwithSlocusglycoprotein(SLG).The pollen ligand probablyis a com-ponentofthepollen coat.SLG-likereceptor1(SLR1)andothercomponents ofthepollencoatprobablyareinvolved inpollenadhesiontothepapillarcell.MOD,modifierofself-incompatibility
Figure 11-10
Wind poilination.Figure 11-11Each cluster of maleoakflowers dangles from a tree branch and sheds ashower ofpollen when the wind blows.These flowerslackpetals.(Dr.JeremyBurgess/SciencePhotoLibrary/PhotoResearchers,Inc.)
Figure 11-11
Figure 11-12Beelikeflowers.The fiowers of thisorchid (Ophrysscolopax)resemble a female bee (Euceralongicormis).Male bees are attracted to the flowers andtransfer pollen during misdirected attempts to copulatewith the flowers.(The yellow sac attached near the bee'santennae is a pollen sac that became attached duringpseudocopulation.)Photographed inSardinia.(NuridsanyePo
Figure 11-12
(A)(B)(D)StamenCarpelSiliaue(fruitPetaSepal(C)Cauline(stem)leafInternodeRosetteleafRootsFIGURE16.1Arabidopsisthaliana.(A)Drawingofa matureArabidopsisplantshowingthevariousorgans,(B)Drawing ofaflower showing the floral organs.(C)An immature vegeta-Figure 11-13tiveplantconsistingofbasal rosetteleavesanda rootsystem(notshown).(D)Amatureplantaftermostoftheflowershave matured and the siliques have developed.(A and BafterClark2o01;CandDcourtesyofCarenChang.)
Figure 11-13