DOC

Photosynthesis

By Julia Butler,2014-02-18 17:16
9 views 0
Photosynthesis

    Photosynthesis

    analyzed.In30degreesC,theaveragevalueofalpha(A)wasO.0476+/

    O.0038.Itisnotquitedifferentfromthevaluesinlow

    elevationareas.alpha(A)isinfluencedbothbytemperatureandbytheratioOfCO2andO

    2partialpressure([CO2]/[O-2]).

    Themeasuredvaluesinthepreviousstudyweremuchlower.Thismightbeduetosystematicerrorsfrominstrumentand

    dataprocessingmethods.Thevaluesofalpha(A)decreasedlinearlywithtemperature.ItdecreasedO.0007inevery1

    degreesCincreaseoftemperature.ThedecreaseslopeissimilartothoseOfC

    3plantsinthepreviousresearches.

    While0

    2

    isconstant,alpha(A)increaseswithCiwithahyperbolicrelationship.Incomparisonwithlowelevationareas.thealpha

    (A)ontheTibetanPlateauismoresensitivetoincreaseOfCO2.

    Keywords:TibetanPlateau;lowatmosphericpressure;C

    3plant;apparentquantumyield;temperature;intercellularCO2

    concentration

    SCIENCEINCHINASERIESD-EARTHSCIENCES2005,48(Supp1.1):182188

    Photosynthesisisimproved.byexogenousglycinebetaineinsaltstressed

    maizeplants

    Yang,XHLu,CM

    ChineseAcadSci,KeyLabPhotosynthesis&EnvironmMolPhysiol,InstBot,Beijing100093,PeoplesRChina

    ShandongAgrUniv,CoilLifeSci,Shandong,PeoplesRChina.

    Abstract:Theeffectsofexogenousapplicationofglycinebetaine(GB)(10mM)ongrowth,le

afwatercontent,wateruse

    efficiency,photosyntheticgasexchange,andphotosystemIIphotochemistrywereinvestigatedinmaizeplantssubjected

    tosaltstress(50and100mMNaC1).Saltstressresultedinthedecreaseingrowthandleafrelativewatercontentaswellas

    netphotosynthesisandtheapparentquantumyieldofphotosynthesis.Stomatalconductance,evaporationrate,andwater

    useefficiencyweredecreasedinsalt

    stressedplants.SaltstressalsocausedadecreaseintheactualefficiencyofPSII(Phi (Psn)),theefficiencyofexcitationenergycapturebyopenPSIIreactioncenters(FV'/F

    m'),andthecoefficientsofphoto

    chemicalquenching(q(P))butcausedanincreaseinnon

    photochemicalquenching(NPQ).Saltstressshowednoeffectson

    themaximalefficiencyofPSIIphotochemistry(Fv/Fm).Ontheotherhand,insalt

    stressedplants,GBapplicationimproved

    growth,leafwatercontent,netphotosynthesis,andtheapparentquantumyieldofphotosynthesis.GBapplicationalso

    increasedstomatalconductance,leafevaporationrate,andwateruseefficiency.Inaddition,GBapplicationincreasedPhi

    (PSII),FV'/F

    m',andq(P)butdecreasedNPQ.However,GBapplicationshowednoeffectsonFv/F

    m.Theseresults

    suggestthatphotosynthesiswasimprovedbyGBapplicationinsalt

    stressedplantsandsuchanimprovementwasasso-

    ciatedwithanimprovementinstomatalconductanceandtheactualPSIIefficiency. Keywords:FOLIAR-APPLIEDGLYCINEBETAINE;PHOTOSYSTEM-II;CHLOROP

    HYLLFLUORESCENCE;ELECTRON

    TRANSPORT;CHOLINEOXIDASE;CHIILtNGTOLERANCE;ENHANCEDTOLER

    ANCE;FREEZINGTOLERANCE;HIGH-

    TEMPERATURE;BACTERIALGENE

PHYSIOLOGIAPLANTARUM2005,124(3):343352

58

Report this document

For any questions or suggestions please email
cust-service@docsford.com