第五节-植物的光形态建成-植物生理学课件

第五节植物的光形态建成光形态建成的概念(photomorphogenesis)向光色素(phototropin)隐花色素(cryptochrome)光敏素(phytochrome)避荫反应（shadeavoidance）

自然界中的光Wavelength(nanometers)700600500400植物的光形态建成（photomorphogenesis）Light-grownArabidopsisEtiolatedcharacteristicsDe-etiolatedcharacteristicsDistinct"apicalhook"(dicot)orcoleoptile(monocot)NoleafgrowthNochlorophyllRapidstemelongation

LimitedradialexpansionofstemLimitedrootelongation

Limitedproductionoflateralroots

ApicalhookopensorcoleoptilesplitsopenLeafgrowthpromoted

ChlorophyllproducedStemelongationsuppressed

RadialexpansionofstemRootelongationpromoted

Lateralrootdevelopmentaccelerated

LightControlsPhotosynthesisRateofGrowthDirectionofGrowthPigmentationFloweringFruitingLeafFallOnsetofDormancy光敏素隐花色素向光蛋白Phototropins

向光素拟南芥的phot突变体拟南芥的phot突变体PHOT1andPHOT2mediate

bluelight-dependentstomatalopeningKinoshitaetal.2001Nature:414,656PhototropinproteinscontaintwoLOV(Light,Ogen,Voltagesensitive)domainsandadownstreamserine/threoninekinase.ThechromophoreisaFlavinmononucleotide(FMN)whichisnon-covalentlyboundwithineachLOVdomain.SchematicillustrationoftheLOVandkinasedomainsofphototropininlight-inducedphosphorylation.

(a)Inthedark,thephosphorylationactivityofthekinasedomainofphototropinisinhibitedbythebindingoftheLOV2domain.(b)Underlightconditions,thephosphorylationactivityofthekinaseisinducedbythereleaseoftheLOV2domain.

Volume9,Issue5,October2006,Pages503-508

Cryptochromes隐花色素http://./Research/cryptochrome/Cryptochromeandtheavian"pass"TheHY4genemaydefineabluelightphotoreceptor

CRYPTOCHROME1(CRY1)Phenotypesofcry2mutantcyr2islatefloweringunderlongdayconditionsThestructureofcryptochromesCryptochromecontrolleddeetiolation.InArabidopsis,cry1andcry2regulatemostoftheblue-light-specificdevelopmentalprograms.Shownareonlyphenotypiceffectsduringdeetiolationcausedbymutationsincry1orcry2.Arabidopsiswildtype(WT)andphotoreceptormutantsgrownfor3daysindarkness(D),whitelight(WL)orcontinuousbluelightof30µmolm-2s-1(highblue,HB)or1µmolm2s1(lowblue,LB),respectivelygivenfromthetop.Inwildtypeseedlings,hypocotylgrowthisinhibitedbybluelightwhereasopeningofthehypocotylhookandcotyledonopeningandexpansionispromotedbybluelight.HBismoreefficientthanLB.Thelackofcry1(cry1)ismostevidentunderHBconditions,whereasthelackofcry2(cry2)beesmoreevidentunderLBconditions,whichisseeninparticularforthedoublemutant(cry1/cry2)(takenfromBatschaueretal.,2007).http://./content/102/34/12270.full.pdf+htmlPhytochrome

光敏素不同波长的光对莴苣种子发芽的影响莴苣种子发芽的作用光谱Lettuceseedgerminationisatypicalphotoreversibleresponsecontrolledbyphytochrome影響‘GrandRapid’萵苣種子發芽的光可逆性照射程序發芽率(%)無(黑暗對照組)14#4*R7098R-Fr

62R-Fr-R7497R-Fr-R-Fr60R-Fr-R-Fr-R7695R-Fr-R-Fr-R-Fr71R-Fr-R-Fr-R-Fr-R8198R-Fr-R-Fr-R-Fr-R-Fr7.#：Tooleetal.,1953(發芽溫度27℃)

*：BewleyandBlack,1982。(發芽溫度24℃，640-680nm的紅光，0.9W/m2，每次照1.5min；>710nm的遠紅光，2.9W/m2，每次照4min)Photoreversibility:

adistinctivefeatureofphytochromechromophoreapoproteinholoproteinSteroStructureofPhytochromeChromophorestructure15105PfrPrtransisomercisisomerStructureconversionofthe

chromophore(phytochromobilin)光敏素蛋白的两种构象模型PfrPrPhytochromeisencodedbyamultigenefamilyPhyA→

responsestoFRPhyB→

responsestoRorwhitelightPre-dominantformsHaveuniquerolesinregulatingresponsestoredandfar-redPhytochromesindifferentspeciesArabidopsis:PHYA,PHYB,PHYC,PHYD,PHYETomato:PHYA,PHYB1,PHYB2,PHYE,PHYFCottonwood（棉白杨）:PHYA,PHYB1,PHYB2Norwayspruce（挪威云杉）:atleast5PHYgenes光敏素类型及其基因类型编码基因存在含量Pfr稳定性作用PIPHYA黄化组织高低去黄化等PIIPHYB/C黄化组织绿色组织低高HIR等植物光敏素反应类型反应类型缩写所需光强光受体光可逆性

实例低辐照度反应LFR1~1000μmolm-2光敏素R/FR可逆莴苣种子萌发拟南芥种子萌发转板藻叶绿体转动极低辐照反应VLFR10-4~10-2μmolm-2光敏素，隐花色素向光色素无燕麦胚芽鞘生长和中胚轴伸长抑制拟南芥种子萌发高辐照度反应HIR10~105μmolm-2光敏素，隐花色素向光色素无幼苗下胚轴伸长抑制弯钩伸直花青素合成LFR&HIRactionspectrumfortheinhibitionofhypocotylelongationofdark-grownlettuceseedlingsPhytochromeisanautophosphorylating

serine/threoninekinaseNuclearlocalizationofphy–GFPfusionproteinsinepidermalcellsofArabidopsishypocotylsPHYA:GFPPHYB:GFPContinuousfar-redlightWhitelightCanmoveinProrPfrformfasttransport(~15min)

maximaltransportundercontinuousFRlight(HIR)MovesonlyinPfrformSlowtransport(severalhours)

RequiresRfortransport;inhibitedbyFRUndercircadiancontrolPIF3

phytochrome-interactingfactor3helix-loop-helixproteintranscriptionfactorsPIFlocalizationCACGTG

GTGCAC光调节元件（LRE）BothPHYTOCHROMEINTERACTINGFACTOR1(PIF1)andSPATULA(SPT)inhibitgerminationbyregulatingthelevelofactivegibberellicacid(GA).TheyactastranscriptionalrepressorsofGAbiosyntheticgenes(GA3ox1andGA3ox2),whicharerequiredtoconverttheGAprecursortoitsactiveform.Inaddition,PIF1activatestheexpressionofaGAcatabolicgene(GA2ox2).Underinductivelightconditions(inwhicharelativelyhighred:far-redratioconvertssufficientphytochromeBtotheactive,nuclear-localizedPfrform),phytochromebindingtriggersthedegradationofPIF1throughubiquitin-mediatedproteolysis,therebyblockingtherepressionofGAlevels.Similarly,coldtreatmentrepressesSPTactivitytopromotegermination.ConstitutivelyPhotomorphogenic(COP)mutantsPhotomorphogenicresponseisalwaysonincopmutants:ConstitutivephotomorphogenicphenotypeinthedarkHypersensitivephenotypeinthelightCOP1encodesanE3ubiquitinligaseCOP10encodesanE2ubiquitinligasevarianttheother8encodemembersofaplexknownastheCOP9signalosome(CSN).someCSNponentsresemblecomponentsofthe26Sproteasome10copmutantsidentifiedLightsignalingpathway植物的避荫反应

shadeavoidanceShadeAvoidanceSyndrome(SAS)ThereducedR:FRratiooflightactsasasignalthatotherplantsarenearbyPlantsofDaturaferoxgrowinginfrontofselectivereflectingmirrorsplacedatca.6cmsouth(southernhemisphere)oftheplants.ThoseinfrontofthemirrorsselectivelyreflectingFRshowincreasedinternodeelongation.KnowTheNeighborthroughPhytochromePhotomorphogenesisUnderContinuousLightdegradationMutantsHelpsRevealTheMechanismofShadeAvoidanceRapidsynthesisofauxinviaanewtryptophan-dependentpathwayisrequiredforshadeavoidanceinplantsYiTao,1,2

Jean-LucFerrer,3,4

KarinLjung,5

FlorencePojer,1,4

FangxinHong,1,2,6JeffA.Long,2

LinLi,2

JavierE.Moreno,7

MarianneE.Bowman,1,4

LaurenJ.Ivans,2,8

YoufaCheng,8

JasonLim,1,2

YundeZhao,8

CarlosL.Ballaré,7

GöranSandberg,9

JosephP.Noel,1,4

andJoanneChory1,2*1HowardHughesMedicalInstitute2PlantBiologyLaboratory,TheSalkInstituteforBiologicalStudies,LaJolla,CA92037,USA3InstitutdeBiologieStructuraleCEA-CNRS-UJF,LaboratoiredeCristallographieetCristallogenèsedesProtéines,41RueJulesHorowitz,38027GrenobleCedex1,France4TheJackH.SkirballCenterforChemicalBiologyandProteomics,TheSalkInstituteforBiologicalStudies,LaJolla,CA92037USA5UmeåPlantScienceCentre,DepartmentofForestGeneticsandPlantPhysiology,SwedishUniversityofAgriculturalSciences,SE-90183Umeå,Sweden6DepartmentofBiostatisticsandputationalBiology,Dana-FarberCancerInstitute,HarvardSchoolofPublicHealth,44BinneyStreetBoston,MA02115,USA7InstitutodeInvestigacionesFisiológicasyEcológicasVinculadasalaAgricultura(IFEVA),ConsejoNacionaldeInvestigacionesCientíficasyTécnicas,andUniversidaddeBuenosAires,AvenidaSanMartín4453,C1417DSEBuenosAires,Argentina8DivisionofBiologicalSciences,SectionofCellandDevelopmentalBiology,UniversityofCalifornia,SanDiego,LaJolla,CA92093-03489UmeåPlantScienceCentre,DepartmentofPlant