简介:BydeterminationofthechangeofendogenoushormoneZr,iPA,GA3,IAAandABAduringdifferentflowerbuddifferentiationstagesofPhyllostachyspraecox,whichisidentifiedthroughbothfieldobservationandlabanalysis,andwiththereferencetothepreviousresearchachievementsonbambooflowering,thefloweringmechanismassumptionofPhyto-HormoneRegulationandGeneActivationofPh.praecoxisinducedinthisarticle:Bambooflowerbuddifferentiationcanbedividedinto3stages,i.e.flowerbudinduction,flowerbudinitiationandflowerbuddevelopment;Bambooleavessenseandreceivefloweringsignalsfromenvironmentstochangeitshormonelevel,esp.ratiosofiPA/ABAandiPA/GA3;FloweringgeneisactivatedoncetheratiosofiPA/ABAandiPA/GA3reachaproperthreshold,anditproducesDNAandRNAcarryingfloweringcodeandtransportsthemtotoporsidebudsnearby,andthenproteinnecessaryforflowerbuddifferentiationcomesout,asaresultofwhichtheflowerbudinductionistriggedandstarted,followedbyflowerbudinitiationanddevelopment.Intheinductionstage,ratioofC/Nisnearlyconstant,butincreasesintheinitiationstage.ThereforeitclarifiesthattherisingofC/Nratiodoesnotbringaboutbamboofloweringinitially,anditisafollow-upreactionsofprocessinitiationofbambooflowering.Itprovesthatbamboorhizomeisdirectlyinvolvedintheflowerbuddifferentiation.Thisassumptioncanwellexplainmysteriousphenomenaofbambooflowering,andbyintegratingthecurrentseveralassumptions,answerthedifficultandperplexingquestionsregardingbamboofloweringwhichhavenotbeenansweredbythepresentassumptions.
简介:Amajorprobleminhybridriceproductionistheoccurrenceofleafsenescenceduringthegrainfillingstagethatcanresultinreductionofyield.Changesincontentsofseveralendogenoushormonesarerelatedtoleafsenescence.TherelationshipbetweenendogenoushormonesandleafsenescenceinthericehybridTiyou418anditsparentsTijinandC418,wasundertakenforinvestigation.Indicatorsofleafsenescence,includingsuperoxidedismutase(SOD)activity,malondialdehyde(MDA)accumulationandchlorophyllcontent,aswellasthecontentsofabscisicacid(ABA),zeatinriboside(ZR),gibberellin(GA1/3)andauxin(IAA)intheleavesweredetermined.Differentratesofleafsenescencewereobservedinthethreematerials.SenescenceoccurredearliestandfastestinTijin,followedbyTiyou418andthenC418.AsimilartrendwasrecordedinABA,ZR,andIAAcontentsduringthegrainfillingstageinthethreematerials.Changesin(GA1/3+ZR+IAA)/ABAratioswerealsosimilar,beingquitestableduringtheearlystageofleafsenescence,anddecreasingmarkedlyduringthelatestage.TheratiodeclinedmoredramaticallyinTijin,inaccordancewithitsfasterleafsenescence.Theresultssuggestthattheratioof(GA1/3+ZR+IAA)/ABAregulateschlorophyllcontent,SODactivity,MDAcontentandmembranelipidperoxidation.Itispostulatedthatendogenoushormonesmayplayaroleintheregulationofleafsenescenceinasystematicway.