植物生理学 英文课件 Chapter 6 Plant growth substances学习资料

lighttemperaturewatermechanicaldamagegasgravitydiseaseandinsideSignalsoutsideChapter6PlantGrowthSubstanceslighttemperaturewatermechanicaldamagegasgravitydiseaseandinsidePlantgrowthsubstances:canregulateplantgrowthanddevelopment(planthormone+plantgrowthregulators)

Planthormone(Phytohormone)OrganiccompoundsSynthesizedinvivoTransportationProfoundeffectsongrowthanddevelopmentVanishinglylowconcentration(<1mmol/L)Auxins生长素类Gibberellins赤霉素类Cytokinins细胞分裂素类Ethylene乙烯AbscisicAcid脱落酸油菜素内酯（Brassinolide，BR）茉莉酸（JasmonicAcid，JA）水杨酸（SalicylicAcid，SA）多胺（Polyamine）?PlantgrowthregulatorsArtificialSimilaractivitiesofplanthormones2,4-DNAA多效唑（PP333）乙烯利DiscoveryChemicalstructureBiosynthesisandbreakdownPhysiologicalfunctionsandmechanismsApplicationsRelatedplantgrowthregulatorsChapter6PlantGrowthSubstances6.1Auxins-thegrowthhormone6.2Gibberellins-regulatorsofplantheight6.3Cytokinins-regulatorsofcelldivision6.4Ethylene-thegaseoushormone6.6Othernaturalplantgrowthsubstances6.7Substancesinhibitplantgrowth6.5AbscisicAcid(ABA)-aseedmaturationandantistresssignal6.1Auxins-thegrowthhormone6.1.1ThediscoveryofauxinCharlesDarwinandFrancisDarwin(1880)Phototropism:

bendingofplanttowardlightCanarygrass胚芽鞘Transparentcap?Opaquebelowtip?F.KÖgl(1934):Indole

aceticacidIAAWaterAuxinfromGreekauxein=“toincrease”or“togrow”AuxinAllplantsPeasMustard,Corn6.1.2Biosynthesisandmetabolismofauxin6.1.2.1Biosynthesispathways

Tryptophan-dependentpathwayIPApathwaymostcommonTAMpathwaybarleyoattobaccotomatoIAAIANpathwayThreefamiliesBrassicaceaePoaceaeBananaIAMpathwayBacteriaZincisrequired!Deficiencyinzinc?

Tryptophan-independentpathwayEvidences:LowlevelsofconversionofradiolabeledTryptophantoIAAOrangepericarp(orp)mutantofmaizeTheorangecolorisduetoexcessindoleTryptophansynthaseareinactiveinOrangepericarpmutantofmaize.Asaresult,thepericarpssurroundingeachkernelaccumulateindole.Theorangecolorisduetoexcessindole.orpmutant:Tryptophan

IAA?No[IAA]?50-foldhigherthanwild-typeWhereisIAAfrominorpmutant?fromtryptophan?No

Tryptophan-independentpathway6.1.2.2SitesofIAABiosynthesisAllplanttissuescanproducelowlevelsofIAA,butshootapicalmeristems,youngleavesanddevelopingfruitsandseedsaretheprimarysites.IAAbiosynthesisisassociatedwithrapidlydividingandrapidlygrowingtissues.6.1.2.3MostIAAintheplantsisina

covalentlyboundformFreeIAA:easytobeextracted,biologicallyactiveBoundIAA:conjugated,hormonallyinactiveEstersofIAAwithglucose

myo-inositolamideTypesofboundIAA

Low-molecular-weightconjugatedauxins

High-molecular-weightconjugatedauxinsIAA-glucan(7-50glucoseunitsperIAA)IAA-glycoproteins(cerealseeds)FunctionsofboundIAAStorage:inseedsandstorageorgansTransportation:duringZea

maysseedgermina-

tion,IAA-myo-inositolistrans-locatedfromtheendospermto

coleoptileviathephloem.Detoxification:Protection:againstoxidativedegradationRegulationlevelsoffreeIAA:FreeIAABoundIAATwosubcellularpoolsofIAAexist:Cytosol:2/3freeIAA,allIAAconjugatesChloroplast:1/3freeIAA6.1.2.4DegradationofIAAEnzymaticbreakdownNonenzymaticbreakdown=photodestructionEnzymaticbreakdownDecarbonoxylation:AminorpathwayNondecarbonoxylationpathways汤玉玮，J.Bonner(1947)IAAoxidase[IAA]don’tchangewhenperoxidaseactivity……

Photodestruction(photooxidation)Invitro,exposedtohigh-intensitylightcanbepromotedbyplantpigments(riboflavin)TheroleinvivoisminorIndole

aldehyde;methylene

oxindole6.1.3AuxintransportPolartransport:fromapicaltothebasalend

basipetally(由上往下地)apex-basestructuralpolarity核黄素PolartransportDonor-receiveragarblockmethodIndependentofgravityAnotherevidence:InvertedbamboostemDifferentiationofrootisstimulatedbyanincreaseinauxinconcentrationWhy?LackofeffectofgravityonpolartransportofauxinVelocityofpolartransport:5~20cm/h>diffusion<phloemtranslocationRequiresmetabolicenergysensitivetooxygendeprivationsensitivetometabolicinhibitorsSpecificforactiveauxins(naturalandsynthetic)neitherinactiveauxinanalogsnorauxinmetabolitesinvolvesspecificproteincarriers(30~150cm/h)CanoccuragainstauxingradientActivetransportWhyauxintransportispolar?MechanismofpolarauxintransportAuxineffluxAuxinuptake/influxPolartransportproceedsinacell-to-cellfashionCWapicalbasaleffluxcarrierconcentratedatthebasalendsofeachcellinthelongitudinalpathwayAuxineffluxcarriersAuxinanion阴离子IAA-doesnotcrossmembranesunaidedImmunofluorescence

microscopyPIN

(PIN-formed)MDR

(Mammalianmultidrug-resistance)PGP(P-glycoprotein)Auxinuptake/influxAuxincanenterplantcellsfromanydirectionbyeitheroftwomechanisms:PassivediffusionSecondaryactivetransportPassivediffusionoftheprotonated(IAAH)formacrossthephospholipid

bilayerPlasmamembraneH+-ATPasenormallymaintainstheCWsolutionataboutpH5.Abouthalfoftheauxin(pKa=4.75)intheapoplastwillbeintheformofIAAH,candiffusepassivelyacrossthemembranedownaconc.gradient.Secondaryactivetransportofthedissociated(IAA-)formviaa2H+-IAAsymporter1/2IAA-doesnotcrossmembranesunaidedSaturableandspecificforactiveauxinsGreaterIAAaccumulationthansimplediffusionAUX1Whyauxintransportispolar?MechanismofauxinpolartransportAuxineffluxAuxinuptake/influxPolartransportproceedsinacell-to-cellfashionCWapicalbasalIAA_IAA_IAA_IAAHIAAHIAA_

Nonpolartransportinthephloem!Longitudinalgradientofauxinfromtheshoottiptotheroottipaffectsstemelongation,apicaldominance,woundhealingandleafsenescence.6.1.4PhysiologicaleffectsofauxinCellElongationAcid-growththeoryIAAcanpromoteacidificationofCWPhospholipaseCIP3,DAGCa2+,CaMAcidificationofCWcanactivatesomeCW-looseningenzymes,andincreaseCWextensibility.β-galactosidaseβ

-1,4-glucanaseXyloglucanaseXETExpansin

PhototropismandgravitropismApicaldominanceSunflower?Direct-inhibitionmodel(budissensitivetoIAA),butIAAdoesnotincreaseinbud!Why？Othermodel?Othersignals?Concept?

Promotestheformationoflateralandadventitiousroots不定根Delaystheonsetoforganabscission（张一帆、王晓峰，未发表资料）Promotesfruitdevelopment瘦果花托Inducesvasculardifferentiation6.1.5AuxinreceptorsABP1(Auxin-bindingprotein1)functionsasanauxinreceptor.ItcanactivateH+-ATPase.Thesubunit(TIR1)ofubiquitinE3ligasecomplex泛素E3连接酶复合体functionsasanauxinreceptor.TIR1=Transportinhibitorresponse16.1.6ApplicationsofartificialauxinsPromoteslateralandadventitiousrootsformationIPA:indolepropionicacidIBA:indolebutyricacidNAA:a-naphthaleneaceticacid2,4-D:2,4-dichlorophenoxyaceticacidDelaystheonsetofleafabscissionPromotesfruitformationanddevelopmentPromotesfloweringofpineappleUniformityoffruitformationandmaturityFreshfruitsupplyinfourseasonsConcentration!ABT生根粉6.2Gibberellins-regulatorsofplantheight6.2.1ThediscoveryofgibberellinsDisease:ricegrowstallbuteliminatesseedproduction“foolishseedling”or“bakanae”disease?E.Kurosawa(1926):inducedbyachemicalsecretedbyafungus-Gibberella

fujikuroi

isolatedfromculturedfiltrates

GibberellinT.Yabuta(1938):obtainedimpurecrystalsCommunicationbarriersandWorldWarIITwogroupsintheWest(1959):ImperialChemicalIndustriesinBritainUSDAinIllinois

GibberellicacidTokyoUniversity(ataboutthesametime):GA1,GA2,GA3

GA3=GibberellicacidGA3=GibberellicacidGA1,GA2,GA3……GA136

GAx6.2.2BiosynthesisandmetabolismofgibberellinsthreestagesStage1:Productionofent-kaureneinplastidsPathways:Isopentenyl

diphosphate异戊烯焦磷酸geranylgeranyl-pp牻牛儿基牻牛儿基焦磷酸内根-贝壳杉烯古巴焦磷酸古巴焦磷酸合成酶内根-贝壳杉烯合成酶Stage2:FormationofGA12inER内根-贝壳杉烯氧化酶内根-贝壳杉烯酸氧化酶Stage3:FormationofallothergibberellinsfromGA12inthecytosolTwoparallelpathwaysfromGA12(13-non-hydroxylated)andGA35(13-hydroxylated)BiologicallyactiveformsBiologicallyinactiveformsKeyenzymes:GA20oxGA3oxGA2oxSitesofbiosynthesisHighestlevels:inimmatureseedsanddevelopingfruitsGibberellinsarebiosynthesizedinapicaltissuesyoung,activelygrowingbudsleavesandupperinternodesrootsfireflyluciferase

FormsofgibberellinsinthecellFreegibberellins:activeConjugatedgibberellins:inactiveGibberellinglycosides:storageform6.2.3TransportofgibberellinsNonpolartransportSynthesizedinbudsandleaves:inphloemSynthesizedinroots:inxylem6.2.4EffectsofgibberellinsongrowthanddevelopmentStimulatestemgrowthindwarfandrosetteplantsCabbageremainsasarosetteinshortdayscanbeinducedtobolt(抽苔)byapplicationsofgibberellinsWhy?Varioussuggestionshavebeenmade,butasyetnoneprovideaclear-cutanswer.removecalciuminCWCalciumcanformbridgesbetweenCWpolymers

promoteactivityofxyloglucan

endotrans-

glycosylase(XET木葡聚糖内转糖基酶)XyloglucansaremaincompoundsofprimaryCW

regulatethetransitionfromjuvenile幼年期

toadultphasesGA4+7GA4+7GA3influencefloralinitiationandsexdeterminationflowerinlongdayscanbeinducedtoflowerbyapplicationsofgibberellinspromotefruitsetandfruitproductionGA3noseedPromotea-amylasea-淀粉酶

productionduringcerealseedgerminationpromoteseedgerminationGApromotesa-amylasegenetranscriptionGApromotesa-amylasemRNAtranslationpromoteseedgerminationCK+GAMannanase(苷露聚糖酶)ApplicationofGAinbeerproductionSeedgerminationisnotnecessary?ApplicationofGAinthree-linehybridriceproductionMalesterilelineMaintainerlineRestorerline1970年，湖南省黔阳农校一位年轻教师与他的助手李必湖和南红农场的冯克珊在海南崖县荔枝沟的野生稻田里发现了一株“野败”。4年后，以这株野败为母本，这位教师成功培育出了三系杂交水稻，从而掀起了水稻生产的“第二次绿色革命”。这个青年教师便是日后被称为“杂交水稻之父”的著名科学家袁隆平，而那株神奇的野败便是一株花粉败育的普通野生稻。ApplicationofGAinbreakingthedormancyofseedsorpotatoesApplicationofGAincut-flowerproduction6.2.5PossiblereceptorofgibberellinsGID1(GIBBERELLININSENSITIVEDWARF1)isareceptorofgibberellinsinrice6.3Cytokinins-regulatorsofcelldivision6.3.1DiscoveryofcytokininsInthe1940sand1950s:Folke

SkoogandcoworkersatUni.ofWisconsinTobaccopith髓

tissuecultureStoredherringspermDNAAutoclavedherringspermDNAFreshherringspermDNAMilleretal.1955:fromtheautoclavedDNA6-furfurylaminopurine=cytokinin(CK)Fromnaturalplantmaterials?yeastextract,tomatojuice,Agreatmanysubstancesweretested:sweetcorn:zeatin(Letham,1963)HSomesyntheticcompounds:CytokininantagonistCommonStructureofCytokininsR1R2R36.3.2BiosynthesisandmetabolismofcytokininsIsopentenylgroup异戊烯基AdeninegroupATP/ADPBiosynthesispathwayIsopentenyl

transferase/IPTCytokinin

synthaseBiosynthesissitesRoottips:Shootapex:GerminatingseedsDevelopingseedsandfruitstransportedinxylemtransportedinphloemFreecytokinins:Conjugatedcytokinins:CTK-glycosides:storageformsSomeplantpathogenicbacteria,insectsandnematodes线虫

secretefreecytokininsTomatosteminfectedwiththecrowngall冠瘿病

Agrobacterium

tumefaciens发根农杆菌Witches’broom丛枝病

onbalsamfir香叶杉2004年10月20日，贵阳Metabolism6.3.3Thebiologicalrolesofcytokinins

CTKsregulatecelldivisioninshootsandrootsCTKdeficientWildtypeOverexpressionofCTKoxidaseWildtypeCTKsuppressesthegrowthofrootsTheIAA/CTKratioregulatesmorphogenesisinculturedtissues

CTKsmodifyapicaldominanceandpromotelateralbudgrowth

CTKsdelayleafsenescence+iptgenecontrolIsopentenyl

transferase/IPT

CTKspromotemovementofnutrients氨基异丁酸

CTKspromotecellexpansioninleavesandcotyledons6.3.4ReceptorsofcytokininsCRE1(cytokinin

receptor1)aproteinsimilartobacterialhistidine

kinases,isacytokininreceptorinArabidopsisAHK2andAHK3arecloselyrelatedtoCRE1inArabidopsis6.4Ethylene-thegaseoushormone6.4.1DiscoveryofethyleneDimitry

Neljubov(1901):Dark-grownpeaseedlingsinthelab

exhibitedtripleresponse:Identifiedethylenefromcoalgasreducedstemelongationincreasedlateralgrowth=swellingabnormal,horizontalgrowth+ethylenecontrolR.Gane(1934):naturalproductofplants1959:GC(gaschromatography)wasintroducedinethyleneresearchEthylenewasrecognizedasaplanthormone(BurgandThimann,1959)6.4.2BiosynthesisofethyleneYangcycle(Shang

FaYang,杨祥发)Methionineistheprecursor甲硫氨酸S-腺苷甲硫氨酸1-氨基环丙烷-1-羧酸5’-甲硫基腺苷RegulationofethylenebiosynthesisAntisenseRNAofACCsynthase,InhibitsformationofACCsynthaseTransgenictomatoFlavr

Savrtomatoin1994

丙二酰-CoA氨基氧乙酸氨基乙氧基-乙烯基甘氨酸6.4.3PhysiologicaleffectsofethylenePromotestheripeningofsomefruitsClimacteric呼吸骤变

fruits:apple,banana,mango……induceslateralcellexpansioninducestheformationofrootsandroothairspromotestheelongationgrowthofsubmergedaquaticspeciesbreaksseedandbuddormancyinsomespeciesinducesfloweringinthepineapplefamilyenhancestherateofleafsenescenceSupraoptimal

auxinconcentrationsstimulateethyleneproduction2,4,5-T(三氯苯氧乙酸),anauxinanalog,theactiveingredientinAgentOrange,waswidelyusedasadefoliantduringtheVietnamWar!It’sabadapplicationofplantphysiologyknowledge!enhancestherateofcut-flowersenescence6.4.4ReceptorsofethyleneETR1(ethyleneresistant)andfourothersimilarproteins,similartobacterialhistidine

kinases,areethylenereceptorinArabidopsisAg+STSCu+6.4.5ApplicationsofethyleneEthrel(liquid)EthylenepH>4.1Promotefruitripening

Promotesecretionoflatex次生代谢物Promoteflowering6.5AbscisicAcid(ABA)6.5.1DiscoveryofABADormancyandabscissionofplantorgansWareingetal.(1963):sycamore(悬铃木)

bud

dormancy←leaf,purifieddorminAddicottetal.(1964):abscissionofimmaturecottonfruitpurifiedabscisinII-aseedmaturationandantistresssignaldorminabscisinIIThesameStructure:contains15carbons1967:abscisic

acidCarbon2determinescisortransisomersCarbon1′isasymmetric,resultingSorR6.5.2Biosynthesisandmetabolismcarotenoid6.5.2.1BiosynthesisABAissynthesizedinchloroplastsorotherplastidswhy?Isopentenyl

diphosphate(5C)vivipary胎萌zeaxanthin

epoxidase玉米黄质环氧化酶生理特性与ABA相似9'-cis-epoxycarotenoiddioxygenase9'-顺式-环氧类胡萝卜素双加氧酶短链类脱氢酶/还原酶aba2AAOABA醛氧化酶类（需要钼辅基）6.5.2.2MetabolismABAcanbeinactivatedbyoxidationandbyconjugationwithsugarsIsopentenyl

diphosphate(IPP)GACTKABA6.5.3TransportationofABAFromleaftoroot:inphloemFromroottoleaf:inxylem6.5.4DevelopmentalandphysiologicaleffectsABApromotestheaccumulationofseedstorageproteinsduringembryogenesisABAlevelsinseedspeakduringembryogenesisSeeddormancyiscontrolledbyABA/GA

ABAinhibitsprecocious(早)germinationandvivipary(胎萌)Vivipary:seedsgerminateonmotherplants秋茄木榄自然界的胎萌（Vivipary）晚熟品种凯特（南亚所,王松标）自然界的胎萌（Vivipary）胡桃麻疯树ABAinhibitsGA-inducedenzymeproductionHydrolytic水解

enzymesthatareessentialforthebreakdownofstoragereservesinseedsa-amylaseEndo-b-mannanaseCKGAABAABAclosesstomatainresponsetowaterstressABApromotesrootgrowthandinhibitsshootgrowthatlowwaterpotentialsABApromotesle