第五節(jié)-植物的光形態(tài)建成-植物生理學課件

第五節(jié)植物的光形態(tài)建成光形態(tài)建成的概念(photomorphogenesis)向光色素(phototropin)隱花色素(cryptochrome)光敏素(phytochrome)避蔭反應（shadeavoidance）

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

LimitedradialexpansionofstemLimitedrootelongation

Limitedproductionoflateralroots

ApicalhookopensorcoleoptilesplitsopenLeafgrowthpromoted

ChlorophyllproducedStemelongationsuppressed

RadialexpansionofstemRootelongationpromoted

Lateralrootdevelopmentaccelerated

LightControlsPhotosynthesisRateofGrowthDirectionofGrowthPigmentationFloweringFruitingLeafFallOnsetofDormancy光敏素隱花色素向光蛋白Phototropins

向光素擬南芥的phot突變體擬南芥的phot突變體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隱花色素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

光敏素不同波長的光對萵苣種子發(fā)芽的影響萵苣種子發(fā)芽的作用光譜Lettuceseedgerminationisatypicalphotoreversibleresponsecontrolledbyphytochrome影響‘GrandRapid’萵苣種子發(fā)芽的光可逆性照射程序發(fā)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(fā)芽溫度27℃)

*：BewleyandBlack,1982。(發(fā)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)光敏素蛋白的兩種構象模型PfrPrPhytochromeisencodedbyamultigenefamilyPhyA→

responsestoFRPhyB→

responsestoRorwhitelightPre-dominantformsHaveuniquerolesinregulatingresponsestoredandfar-redPhytochromesindifferentspeciesArabidopsis:PHYA,PHYB,PHYC,PHYD,PHYETomato:PHYA,PHYB1,PHYB2,PHYE,PHYFCottonwood（棉白楊）:PHYA,PHYB1,PHYB2Norwayspruce（挪威云杉）:atleast5PHYgenes光敏素類型及其基因類型編碼基因存在含量Pfr穩(wěn)定性作用PIPHYA黃化組織高低去黃化等PIIPHYB/C黃化組織綠色組織低高HIR等植物光敏素反應類型反應類型縮寫所需光強光受體光可逆性

實例低輻照度反應LFR1~1000μmolm-2光敏素R/FR可逆萵苣種子萌發(fā)擬南芥種子萌發(fā)轉板藻葉綠體轉動極低輻照反應VLFR10-4~10-2μmolm-2光敏素，隱花色素向光色素無燕麥胚芽鞘生長和中胚軸伸長抑制擬南芥種子萌發(fā)高輻照度反應HIR10~105μmolm-2光敏素，隱花色素向光色素無幼苗下胚軸伸長抑制彎鉤伸直花青素合成LFR&HIRactionspectrumfortheinhibitionofhypocotylelongationofdark-grownlettuceseedlingsPhytochromeisanautophosphorylating

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

maximaltransportundercontinuousFRlight(HIR)MovesonlyinPfrformSlowtransport(severalhours)

RequiresRfortransport;inhibitedbyFRUndercircadiancontrolPIF3

phytochrome-interactingfactor3helix-loop-helixproteintranscriptionfactorsPIFlocalizationCACGTG

GTGCAC光調節(jié)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植物的避蔭反應

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

G?ranSandberg,9

JosephP.Noel,1,4

andJoanneChory1,2*1HowardHughesMedicalInstitute2PlantBiologyLaboratory,TheSalkInstituteforBiologicalStudies,LaJolla,CA92037,USA3InstitutdeBiologieStructuraleCEA-CNRS-UJF,LaboratoiredeCristallographieetCristallogenèsedesProtéines,41RueJulesHorowitz,38027GrenobleCedex1,France4TheJackH.SkirballCenterforChemicalBiologyandProteomics,TheSalkInstituteforBiologicalStudies,LaJolla,CA92037USA5Ume?PlantScienceCentre,DepartmentofForestGeneticsandPlantPhysiology,SwedishUniversityofAgriculturalSciences,SE-90183Ume?,Sweden6DepartmentofBiostatisticsandputationalBiology,Dana-FarberCancerInstitute,HarvardSchoolofPublicHealth,44BinneyStreetBoston,MA02115,USA7InstitutodeInvestigacionesFisiológicasyEcológicasVinculadasalaAgricultura(IFEVA),ConsejoNacionaldeInvestigacionesCientíficasyTécnicas,andUniversidaddeBuenosAires,AvenidaSanMartín4453,C1417DSEBuenosAires,Argentina8DivisionofBiologicalSciences,SectionofCellandDevelopmentalBiology,UniversityofCalifornia,SanDiego,LaJolla,CA92093-03489Ume?PlantScienceCentre,DepartmentofPlant