简介:ThetransgenicriceKMD1,expressingasyntheticCry1AbgenefromBacillusthuringiensis,showedeffectiveresistancetoSignificantdeclineswererevealedinfoodconsumptionandgrowthoftheolderRLFnymphsfedonthecut-leavesoftransgenicKMD1plants.TheincreaserateoffoodconsumptionbylarvaefedonKMD1wasdrasticallylowerthanthoseonXiushui11.FoodconsumptionwasvariedwithdifferentinstarswhenthelarvaefedontheBtrice.Thoseoffourth-andfifth-instarlarvaeweredifferentcomparedtothethird-instar,lowerthanthoseonthenon-transgenicricebutstillincreasedalittlewhenthefeedingtimeprolonged.ItisindicatedthatyoungerRLFlarvaearemoresensitivetoBtricethanolderones.Also,about81%,78%and68%ofthethird-,fourth-andfifth-instarRLFlarvaediedwithin72hoursbioassayperiodonKMD1leaves,respectively.TheseresultsdemonstratedthatBt-transgeneinKMD1riceconferssubstantialprotectionagainstinfestationswitholderRLFlarvae.
简介:Smallubiquitin-likemodifier(SUMO)-conjugatingenzymesareinvolvedinpost-translationalregulatoryprocessesineukaryotes,includingtheconjugationofSUMOpeptidestoproteinsubstrate(SUMOylation).SUMOylationplaysanimportantroleinimprovingplanttolerancetoabioticstresssuchassalt,drought,heatandcold.Herein,wereportedtheisolationofOsSCE1(LOC_Os10g39120)geneencodingaSUMO-conjugatingenzymefromrice(Oryzasativacv.Nipponbare)anditsfunctionalvalidationinresponsetodroughtstress.TheE2enzyme,OsSCE1,isoneofthreekeyenzymesinvolvedintheconjugationofSUMOtoitstargetproteins.ActivatedSUMOistransferredtothecysteineofanE2enzymeandthentothetargetlysineresidueofthesubstrate,withorwithoutthehelpofanE3SUMOligase.ExpressionofOsSCE1wasstronglyinducedbypolyethyleneglycol6000(PEG6000)treatment,whichsuggestedOsSCE1maybeinvolvedinthedroughtstressresponse.OverexpressionofOsSCE1(OsSCE1-OX)inNipponbarereducedthetolerancetodroughtstress.Conversely,thedroughttolerancewasslightlyimprovedbytheknockdownofOsSCE1(OsSCE1-KD).TheseresultswerefurthersupportedbymeasurementofprolinecontentinOsSCE1-OXandOsSCE1-KDtransgeniclinesunderinduceddroughtstress,whichshowedOsSCE1-KDtransgeniclinesaccumulatedhigherprolinecontentthanthewildtype,whereasOsSCE1-OXlinehadlowerprolinecontentthanthewildtype.ThesefindingssuggestedOsSCE1mayplayaroleasanegativeregulatorinresponsetodroughtstressinrice.
简介:Nitrogen(N)useefficiencyisusuallylessthan50%,anditremainsamajorprobleminricecultivation.Controlledreleasefertilizer(CRF)technologyisoneofthewell-knowneffortstoovercomethisproblem.TheefficiencyofCRF,however,isverymuchdependentonthetimingofnutrientrelease.ThisstudywasconductedtodeterminetheprecisetimeofNuptakebyriceasaguidelinetodevelopefficientCRF.FertilizerNuptakebyriceatdifferentgrowthstageswasinvestigatedbyusing15Nisotopictechnique.Ricewasplantedinpots,with15NureaasNsourceattherateof120kg/hm2.Potassiumandphosphoruswereappliedatthesamerateof50kg/hm2.Standardagronomicpracticeswereemployedthroughoutthegrowingperiods.Riceplantswereharvestedeverytwoweeksuntilmaturationatthe14thweekandanalyzedfortotalNand15Ncontent.Nitrogenderivedfromfertilizerwascalculated.TotalNuptakeinplantsconsistentlyincreaseduntilthe11thweek.Afterthat,itstartedtoplateauandfinallydeclined.Moreover,Nutilizationbyriceplantspeakedat50%,whichoccurredduringthe11thweekaftertransplanting.Nderivedfromfertilizerinriceplantswereintherangeof18.7%to40.0%inallplanttissues.TheremainingNwasderivedfromsoil.Basedonthisstudy,NreleasefromCRFshouldcompletebythe11thweekafterplantingtoensurethemaximumfertilizerNuptakebyriceplants.EfficientCRFshouldcontributetohigherNderivedfromfertilizerwhichalsoresultedinahighertotalNuptakebyriceplants,increasingthepotentialofricetoproducehigheryieldwhileatthesametimeofreducingloss.
简介:Twonewlybredhybridricecombinations,superhigh-yieldingLiangyoupeijiu(Pei'ai64S×9311)andPei'ai64S/E32(Pei'ai64S×E32)wereusedtoinvestigatethephotosyntheticcharacteristicsunderhightemperatureincomparisonwithhybridriceShangyou63.Hightemperaturecausedadecreasedphotosyntheticefficiencyandaggravatedphotoinhibition.TheoptimumtemperatureforphotosyntheticelectrontransportationandphotosyntheticCO2fixationwereabout28℃and35-40℃respectively.Linearelectrontransportationismoresensitivetohightemperaturethanthephotochemicalprocess.Themechanismofhightemperatureadaptationwaspossiblyasfollows:superhigh-yieldingricehasquicklyincreasingcarotenoid,whichactedasamorefavorableantioxidantsystemtoreducetheactiveoxygenproductionandavoiddamagetothephotosynthesissystem;superhigh-yieldingricehasahigherefficiencyofxanthophyllscycletodissipateexcessheatenergy;superhigh-yieldingricehasamorestablephotosyntheticfunction,higherphotosyntheticefficiencyandmoreheatstableproteincontent.