植物的營養(yǎng)問題(NutritionofPlant)

土壤營養(yǎng)：Water,MineralelementsFood?植物的營養(yǎng)問題(NutritionofPlant)

土壤營養(yǎng)：Water,Mineralelements空氣營養(yǎng)：Photosynthesis

(光合作用)碳素同化作用（carbonassimilation）Chapter3Photosynthesis3.1

Thediscoveryofphotosynthesis3.2

Theimportanceofphotosynthesis3.3

Chloroplastandchloroplastpigments3.4

Mechanismsofphotosynthesis3.5

Factorsaffectingphotosynthesis3.6

Solarenergyutilizationofplants3.7

Translocationofphotosynthetic

products3.1ThediscoveryofphotosynthesisPhotosynthesis:

CO2+H2O（CH2O）+O2

LightGreenplant

1771,JosephPriestly:mint/candle,“oxygen”

1779,JanIngenhousz:Light

1782,J.Senebier：CO2andO2

1804,N.T.deSaussure:H2Oand[CO2]=[O2]

1864,J.Sachs:CH2O(Starchgrain/light)Backcarbohydrate1st3.2TheimportanceofphotosynthesisGreenfactorytoproduceorganiccompounds糧、棉、油/衣、食、住、行

EnergytransformationLight(solar)energyChemicalenergy food,oil,coal,gas,wood.H2SourceofoxygenBreath;Ozonelayer;RecycleofCO2

FoodO2Energy“大海航行靠舵手，萬物生長靠太陽”

Rice/noodle/meatphotosyntheticscissorsmagicFutureshapeofhumanbeings?!GreenBack3.3Chloroplast葉綠體

andchloroplastpigments3.3.1Placesofphotosynthesis2ndconceptofphotosynthesis3rdconceptofphotosynthesis3.3.2Morphology,structureandchemicalcomponentsofchloroplastMorphology:flatandellipsoid(橢圓體)Chloroplastcanmovement,functions?Structure:2D被膜=外+內間質類囊體基粒類囊體間質類囊體Lipiddroplet脂滴Structure:3DChemicalcomponents:Mainchemicalcompound?Proteins:(onlamellae)proteincomplex,plastocyanin(質體藍素PC)Water(75%)(instroma)enzymes(Rubisco,etc)Lipids:glycosylglyceride糖基甘油酯;fewP-,S-DNAandRNA:Minerals:Mg,etcCarbohydrates:starch,etcPigments:8%ofdryweightofchloroplastAbsorblightSemiautonomousorganelles蛋白質灰分貯藏物質脂類色素?Chlorophylls

葉綠素Carotenoids

類胡蘿卜素Phycobilins

藻膽素3.3.3ChemicalcharacteristicsofphotosyntheticpigmentsChlorophylls:color,solubility,structure

Chla:C55H72O5N4Mg;blue-green

Chlb:C55H70O6N4Mg;yellow-greenCH3葉綠酸(雙羧酸)的脂pyrrole吡咯環(huán)副環(huán)porphyrin卟啉環(huán)共軛電子系統(tǒng)C20H39ChlaHPolarity?Chlb﹤CHOCuCarotenoids:color,solubility,structure

carotene胡蘿卜素:C40H56;orange-yellow；abg

xanthophyll/carotenol葉黃素:C40H56O2;yellowPolarity?b-caroteneXanthophyll/Carotenol紫羅蘭酮環(huán)OHOHCarotenol

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CarotenePhycobilins/Phycobiliproteins:color,structure

phycoerythrin:red

phycocyanin:bluephycoerythrinphycocyanin研究葉綠體色素而獲諾貝爾獎者威爾施泰特(德)1915：葉綠素是由葉綠醇和含鎂的葉綠酸所形成的酯。研究葉綠體色素而獲諾貝爾獎者費歇爾(德)1930：研究卟啉類化合物，其中包括葉綠素和鐵血紅素，經(jīng)費歇爾修訂的葉綠素分子結構一直沿用至今。制成人造血紅素。研究葉綠體色素而獲諾貝爾獎者卡勒因(瑞士)1937：研究類胡蘿卜素等物質的化學結構。研究結果對研究類胡蘿卜素這一天線色素的光合特性具有重要作用。研究葉綠體色素而獲諾貝爾獎者伍德沃德(美)1965：于1960年合成葉綠素3.3.4OpticalcharacteristicsofphotosyntheticpigmentsIrradiationenergy:energyoflight Lighthascharacteristicsofbothaparticle(photon)andawave.Planck’slaw:E(quantum)=hv=hc/l

Absorptionspectrum吸收光譜:Solarspectrum:300-2600nm?Visiblespectrum:400-700nmAbsorptionspectrumLight連續(xù)光譜吸收光譜LightAbsorptionspectrumcurveChlaChlbPhycoerythrinb-caroteneBacteriochlorophyllaPeakandotherwavelengthsFluorescence熒光現(xiàn)象

and

Phosphorescence磷光現(xiàn)象Fluorescence:excitedchlorophyllcanre-emitaphotonwhenitreturnstoitsgroundstate.Invitro/solution: greenintransmission,redinreflection?Invivo/livingcell:?Phosphorescence:第一三線態(tài)

groundstateCH3吡咯環(huán)副環(huán)卟啉環(huán)共軛電子系統(tǒng)C20H393.3.5Biosynthesisandbreakdownofchlorophyllarecomplexpathways谷氨酸MgFeChlorophyllFerroheme亞鐵血紅素膽色素原x2原卟啉IXPlantAnimal原脫植基葉綠素aChlb脫植基葉綠素a葉綠醇（植醇）葉綠素的降解葉綠素b還原酶類囊體內的葉綠素b

葉綠素a

葉綠素酶脫鎂整合酶

脫植基葉綠素a

脫鎂葉綠素a氧化酶脫鎂葉綠素a

水溶性無色產物3.3.6BiosynthesisofcarotenoidsChlorophylls/carotenoids=3Chla/Chl

b=3Xanthophyll/Carotene

=2??anthocyanin?Breakdown3.3.7LeafcolorLight:?EtiolationTemperature:?Mineralelements:N:?Mg:?Fe:?Mn:?Cu:?Zn:??Back3.3.8FactorsaffectingchlorophyllbiosynthesisChlorosis缺綠3.4Mechanismsofphotosynthesis“太陽公公為什么能把樹曬大呢？”

“太陽公公為什么能把樹曬大呢？”

Solarenergy

Electricenergy Absorption,transferandconversionofsolarenergy

ElectricenergyActivechemicalenergy(ATP/NADPH) Electrontransportandphotophosphorylation

ActivechemicalenergyStablechemicalenergy(carbohydrate) Carbonassimilation同化3.4Mechanismsofphotosynthesis3.4.1AbsorptionandtransferofsolarenergymostChla;allChlb,carotenoidsandphycobilinsLight-harvesting/Antennapigments:Reactioncenterpigments:fewspecialChlaResonance共振photon

3.4.2ConversionofsolarenergytoelectricenergyReactioncenter:Reactioncenterpigments:P700/P680(Chla)PrimaryelectrondonorandacceptorPhotochemicalreactionDonor.P.AcceptorLightDonor.P*.AcceptorDonor.P.Acceptor-Donor.P+.Acceptor-Donor+.P.Acceptor-LightenergyElectricenergyRedoxReactionReduction/Oxidation

Twophotosyntheticunit/Photosystem(PS)Twophotosystemsworkintandem接力Howweretwophotosystemsdiscovered?Reddrop:Emerson,bythelate1950s.680nmEnhancementeffect/EmersoneffectBytwophotosystemsworkingintandem接力Emerson,1957:700nm680nmTwophotosystemsworkintandem接力Structure:2D被膜=外+內間質類囊體基粒類囊體間質類囊體Lipiddroplet嗜餓滴/脂滴Organizationoftheproteincomplexesofthethylakoidmembrane3.4.3ElectronandprotontransportOriginaledonor:WaterEndeacceptor:NADP+ZschemePhotosyntheticchainCyclic-Noncyclic-autonomously?StromaLumenPSIIComplexes=CoreComplexPSIIlight-harvestingcomplex:LHCIIOxygen-evolvingcomplex:OECOECLocation:lumensideComponents:peptides(33,23,18kD)

Mncomplex,Ca+,Cl-Oxygenevolvingmechanism(Wateroxidizingclock)2H2OO2+4H++4e-CO2+2H2O*（CH2O）+O*2+H2OlightchloroplastNewconceptofphotosynthesis2H2OO2+4H++4e-CO2+2H2O*（CH2O）+O*2+H2OlightchloroplastNewconceptofphotosynthesis2H2OO2+4H++4e-CO2+2H2O*（CH2O）+O*2+H2OlightchloroplastNewconceptofphotosynthesisPSIComplexes德國科學家戴森霍弗、胡貝爾、米歇爾測定出了光合作用反應中心膜蛋白-色素的三維空間結構，揭示出電子和能量的傳遞作用，共同獲得1988年度諾貝爾獎。3.4.4PhotosyntheticphosphorylationPmfH+H+H+H+H+H+H+Photophosphorylation光合磷酸化ATPSynthaseorCouplingfactorProductsofCyclic/NoncyclicElectronTransportATP,Oxygen,NADPH?OxygenNADPHATPAssimilatorypower同化力3.4.5Carbonassimilation同化Location:stromaofchloroplast3pathways: CalvinCycle/C3pathway C4pathway CAM3.4.5.1TheCalvincycle(M.Calvin)PhotosyntheticcycleReductivepentose戊糖

phosphatepathway(RPPP)C3pathway14CO2Paperchromatograph層析AutoradiogramsshowingtheproductsofphotosynthesisinthealgaChlorellapyrenoidosaaftervarioustimesofexposureto14CO2(bottom)2s,(middle)7s,(top)60s.Notetheincreasingimportanceof3-PGA(3-phosphoglycerate,3-磷酸甘油酸)andothersugarphosphatesastheexposuretimeisshortenedRuBP:Ribulose-1,5-bisphosphate核酮糖-1,5-二磷酸Carboxylationinorganic-organicx6RuBPCaseReductionx6x1x5x3激酶6x磷酸丙糖3CRegeneration4C5C6C3C

x53C6C7C7C5C5Cx1x1x1x1x13C5C5C5C5Cx3赤蘚糖景天庚酮糖木酮糖核糖3x3x6xx66x5x3xGlyceraldehyde-3-phosphate1xFoodofplants“太陽公公為什么能把樹曬大呢？”

RegulationoftheCalvincycleLight-dependentenzymeactivationregulatestheCalvincycleLight-dependentionmovementsregulatetheCalvincycleLightreaction??? 1stand2ndmainstepsDarkreaction??? 3rdmainstep3.4.5.2TheHatch-SlackPathwayDiscoveredbyHatchandSlackfromAustraliain1966,insometropicalandsub-tropicalplants,e.g.cereals,whichhavespecialleafanatomic解剖

featuresC4monocot,maizeC3monocot,riceC4-pathway:C4-dicarboxylicacidpathwayC4-plantsC3-plantschloroplastKranz=wreathchloroplastcontaining維管束鞘Manyplasmodesmata胞間連絲

betweenmesophyllandbundlesheathcells碳酸酐酶TheHatch-SlackPathway（C4pathway）草酰乙酸蘋果酸PEPCase

丙酮酸4CPEPPEPC2xATP3.4.5.3CAM(Crassulacean

AcidMetabolism)NightDay景天酸代謝Open?Close?NightStomatamovementOpen?Close?DayCAMplantsProblem???4Chigh[organicacid]low[organicacid]C4Plants:?C3Plants:?CAMPlants:?MaizeRiceCrassulaceaeDifferentplanttypesclassifiedaccordingtophotosyntheticpathways3.4.5.4PhotorespirationC2OxidativePhotosyntheticCarbonCycleDarkrespirationPathway(inthreeorganelles):Concept:RuBP磷酸乙醇酸RuBP

Oxygenase

RubiscoRuBPC2C3CCO2CHLOROPLAST乙醛酸PEROXISOME[CO2]/[O2]CO2BiologicalFunctionofPhotorespirationUnderhighlightintensityandlowintercellularCO2concentration,dissipateexcessATPandreducingpowerfromthelightreactions.IsUnknownBack3.5FactorsaffectingphotosynthesisPhotosyntheticrate:mgCO2/dm2/h;μmolCO2/m2/sApparentphotosyntheticrate=NetphotosyntheticrateTruephotosyntheticrate=NPR+Respirationrate3.5.1Light

Lightintensity:μmol/m2/s光補償點Lightsaturationpoint???合理密植?Xhighersaturationpointlowerlightcompensationpoint濱藜屬，藜科細辛屬，馬兜鈴科

Photoinhibition:Mechanismisunclear?LightofdifferentwavelengthCloudy:moreblueandgreenlightUndercanopy:moregreenlightUpperwater:greenalgaeDeepwater:moregreenandbluelight,redalgaePhycoerythrin3.5.2CO2CO2saturationpoint???>>

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CO2intheatmosphereCO2compensationpoint:C4<C3CO2intheatmosphere:360ppmatpresentGreenhouseeffectWaterplants?3.5.3TemperatureEnzymeactivitiesApparentphotosyntheticrate?Respiration3.5.4WaterMaterial:1%StomamovementTransportation3.5.5Essentialmineralelements

Iron---FeManganese---MnBoron---BCopper---CuZinc---ZnMolybdenum---MoChlorine---ClNickel---NiSodium---NaNitrogen---NPhosphorus---PPotassium---KCalcium---CaMagnesium---MgSulfur---SSilicon---SiWhyphotosyntheticrateofC4plantsismuchmorehigherthanthatofC3plants?

Specialleafanatomicfeatures:KranzPhysiologicalfeatures:Affinity親和性

toCO2:PEPC>RuBPCCO2compensationpoint補償點:C4<C3CO2pump:C4

Photorespiration:C4<C3Back3.6Solarenergyutilizationofplants3.6.1Efficiencyforsolarenergyutilization3.6.2Howtoincreasephotosyntheticrate?elongatephotosynthetictime:temporalandspatial

increasephotosyntheticarea:

合理密植、改變株型increaseCO2concentration:aeration,CO2fertilizerdecreasephotorespiration?BackPhotosynthesislocation:leavesConsumedplaces:alllivingcells

Storageorgans:seed,fruit,tuber,rhizoma,3.7TranslocationofphotosyntheticproductsSource源:cells,tissues,organs,produceandexportphotosyntheticproducts.leafSink庫:?stemetc.Thetransitionoftheleaffromsinktosourcestatustranslocation3.7.1PathwaysoftranslocationWaterandmineralsaretransportedin???Photosyntheticproductsaretranslocatedinphloem!Howdoyouknow?

Girdling環(huán)割OnthestemsofbranchesOnthemainstem?Hibiscusrosa-sinensis朱槿（大紅花）Onthemainstem?人要臉，樹要皮？Howdoweknow?

Girdling環(huán)割ApplicationinfruitproductionHowdoweknow?

Girdling環(huán)割ApplicationinseedlingproductionCalliandra

haematocephala朱纓花

Isotopetracing同位素示蹤Isotopetracing+surgicaltreatmentBidirectionaltransportationSievetubeelementsandcompanioncellsarelivingcells!3.7.2Typeofphotosyntheticproductstranslocated????????????Whattype?Howdoyouknow?Aphid蚜蟲styletChemicalcompositionofphloemsap:Water:Drysubstances:Sucrose:90%ofdryweightRaffinose,StachyoseandVerbascose:few棉子糖水蘇糖毛蕊花糖半乳糖Aminoacids:Hormones:Inorganicions:K,P,Cl,etc.ProteinsOrganicacids3.7.3.1Phloemloading3.7.3.2Translocationinsieveelements3.7.3.3Phloemunloading3.7.3Detailtranslocationsteps3.7.3.1Phloemloading

Inmesophyll/bundlesheathcells:ChloroplastCytosolMesophyll/bundlesheathcellsSieveelements

Frommesophyll/bundlesheathcellsPhloemparenchymacellsFromphloemparenchymacellsSieveelementsHowdoessucrosei