全 文 ：第 25卷第 8期
2005年 8月
生 态 学 报
ACTAECOLOGICASINICA
Vol.25,No.8
Aug.,2005
不同浓度海水对菊芋幼苗生长及生理生化特性的影响
隆小华,刘兆普*,郑青松,徐文君
(南京农业大学资源与环境学院,南京 210095)
基金项目:国家 863节水农业重大专项计划资助项目(2002AA2Z6041);国家 863海洋生物技术计划资助项目(2003AA627040)
收稿日期:2004-09-17;修订日期:2005-06-15
作者简介:隆小华(1979～),男,江苏丹阳人,博士生,主要从事海水灌溉农业研究.E-mail:lxh108@yahoo.com.cn
* 通讯作者 Authorforcorrespondence.E-mail:sea@njau.edu.cn
Foundationitem:National"863"hightechnologyprogramofsavingwaterofChina(ApprovedNo.2002AA2Z4061)andtheNational"863"
programofhalobiostechnology(ApprovedNo.2003AA627040)
Receiveddate:2004-09-17;Accepteddate:2005-06-15
Biography:LONGXiao-Hua,Ph.D.candidate,mainlyengagedinseawaterirrigatingagriculture.E-mail:lxh108@yahoo.com.cn
摘要:种植抗盐耐海水植物是合理利用和开发海涂资源的有效措施之一。采用水培的方式,用 1/2Hoagland营养液培养菊芋幼
苗至 6叶完全展开时进行处理,设 0%(对照)、10%、25%和 50%海水 4个处理。随后分别在第 4、8和 12天采样进行分析,研究
不同浓度海水对菊芋幼苗生长、体内渗透物质的积累、保护性酶活性、膜透性及离子吸收分布的影响情况。结果表明:(1)在不同
浓度海水处理下,菊芋地上部、地下部总鲜重及干物质重从 0%到 25%海水浓度没有明显变化,在 50%海水胁迫下显著下降,
干物质百分比则为 50%海水处理的最高。随着时间延长,10%海水处理下,菊芋幼苗茎叶和根鲜重均增加,但与对照没有显著
差异,25%海水处理生长速率较对照低,而 50%海水处理下根鲜重和干重都降低。(2)随着时间的延长、海水浓度的增加,菊芋
幼苗叶片保护性酶系 SOD、POD、CAT的活性呈上升趋势,在 10%海水处理下膜脂过氧化物 MDA含量甚至低于对照,而 50%
海水处理下的 MDA含量较其他处理高,在 10%和 25%海水处理下膜透性较对照变化不显著,而 50%海水处理下膜透性增加
明显,且随时间延长更显著。(3)菊芋幼苗叶片脯氨酸和可溶性糖含量随海水浓度增高而显著增加,随着时间的延长,10%和
25%海水处理下,脯氨酸含量先增加后降低,而 50%海水处理下,脯氨酸含量一直在升高,而 10%、25%和 50%海水处理下,可
溶性糖含量先增加后降低。随海水浓度增高,菊芋幼苗地上部单位干重积累的 Na+和 Cl-依次增大,且随着时间延长,10%、
25%和 50%海水处理下地上部 Na+和 Cl-含量均增大;而 K+与 Na+积累情况不同,K+在 25%海水胁迫下地上部单位干重积
累得最多,随着时间延长,25%和 50%海水处理下地上部 K+含量均降低,且 50%海水处理下降低幅度更大;地下部单位干重积
累的 Na+、Cl-和 K+情况与地上部单位干重积累的各离子趋势相似。由此可见,菊芋能够通过生理生化机制适应一定浓度海水
的灌溉,即利用一定浓度海水灌溉菊芋是安全有效的。
关键词:海水胁迫;菊芋;渗透物质;酶活性;膜透性;离子
文章编号:1000-0933(2005)08-1881-09 中图分类号:Q945.78 文献标识码:A
Effectsofseawaterwithdifferentconcentrationsongrowthandphysiological
andbiochemicalcharacteristicsofHelianthustuberosusseedlings
LONG Xiao-Hua,LIU Zhao-Pu*,ZHENG Qing-Song,XU Wen-Jun (CollegeofResourcesandEnvironmental
SciencesofNAU,Nanjing210095,China).ActaEcologicaSinica,2005,25(8):1881～1889.
Abstract:Growingplantsthatcantolerateseawaterisoneofthevalidmeasuresofreasonableuseandexploitationofcoastal
beaches.Potexperimentswerecarriedouttostudyeffectsofdifferentconcentrationsseawaterongrowth,osmotica
accumulationantioxidantenzyme,membraneleakageandiondistributionsofHelianthustuberosusseedlings.Fourtreatments
withsixreplicatesconsistingof0% (distiledwater),10%,25% and50% seawaterweresetupbyarandomizedcomplete
blockdesign.Plantaerialpartsandrootswereharvested4,8and12daysaftertreatmentandassayedforfreshweight(FW),
dryweight(DW),andcontentsofwater,Na+,K+ andCl-.Meanwhile,leaveswereassayedforactivitiesofantioxidant
enzymes,malondialdehyde(MDA)contents,electrolyticleakagepercentage(ELP),prolineandsoluble-sugarcontents.
Resultswereasfolows:(1)Comparedwiththecontrol,therewereslightchangesofFW andDW inrootsa
===================================================================
ndaerialpartsof
Helianthustuberosusseedlingstreatedwith10% and25% seawater,whereasasignificant(p<0.05)decreaseinbothFW and
DW occurredunder50% seawater.Butthewatercontentinaerialpartsandrootswerethelowestunder50% seawater.(2)
TheactivitiesofSOD(superoxidedismutase),POD(peroxidase)andCAT(catalase)inleavesofseawater-stressedplants
werestimulatedsignificantlycomparedwithcontroledplants,andincreasedwithincreasingseawaterconcentrations.
Comparedwiththecontrol,therewasslightchangeofELPinleavesofHelianthustuberosusseedlingstreatedwith10% and
25% seawater,whereasELPincreasedsignificantlywiththetreatmentof50% seawater.Withtimelasting,ELPincreased
moreunder50% seawater.(3)Contentsofprolineandsoluble-sugarincreasedwithincreasingseawaterconcentrations.
ContentsofprolineincreasedonDay8anddecreasedonDay12under10% and25% seawater,butincreasedsignificantlyon
Day8andonwardunder50% seawater.Contentsofsoluble-sugaronDay8increasedcomparedwiththoseonDay4and
decreasedonDay12under10%,25% and50% seawater.ContentsofNa+ andCl- intheaerialpartsincreasedwithincreasing
seawaterconcentration.ComparedwithNa+,K+ contentswerehighestunder25% seawater.AndthetendenciesofNa+,Cl-
andK+ inrootsweresimilarwiththoseintheaerialparts.TheresultsofthepresentstudystronglysuggestthatHelianthus
tuberosuscouldadaptappropriateconcentrationseawaterirrigationthroughphysiologicalandbiochemicalmechanisms,which
waseffectiveandsecure.
Keywords:seawaterstress;Helianthustuberosus;osmotica;antioxidantenzyme;membranepermeability;ions
1 INTRODUCTION
Salinitytoxicityisaworldwideagriculturalandeco-environmentalproblem.Approximatelyone-thirdoftheworldland
surfaceisaridorsemi-arid[1],inwhichfreshwatershortageisthemainlimitingfactorforsustainabledevelopmentof
agriculture[2～4].Itisestimatedthatthereareapproximately18000kmcoastlineand20779km2salinisedsoilsincoastalareasin
China[4].Seawaterirrigatingagricultureisanewbranchoftraditionalagriculturesandoneofvalidmeasuresofreasonableuse
andexploitationofseawater,salinesoilsalongthecoastandsalt-tolerantplants.Selectionofseawaterconcentrationisthe
mostimportantforplantproductionofseawaterirrigatingagriculturebecauseplasmamembranesareinjuredbythe
accumulationofexcesssaltsinplanttissueswhengrownunderstrongseawaterirrigation[4].
Helianthustuberosusisconsideredtobeabletobearcold,drought,leannessandsalinity.Itsaerialpartandtuberprovide
goodqualityfeedandthetubercanbeusedasvegetableandforalcoholproduction[4～6].Wehavecarriedoutfieldexperiments
ofseawaterirrigatingagricultureonHelianthustuberosusintypicalsemi-aridcoastalareasofnorthChinasince1999[4].
TheobjectiveofthisresearchwastoinvestigategrowthandthephysiologicalandbiochemicalmechanismsofHelianthus
tuberosusunderseawaterstress.Changesofthegrowth,inorganicandorganicosmoticas,antioxidantenzymesandinjuryof
membraneofseedlingsontime-dependentwerestudiedinthepresentworkbywaterculturebecauseHelianthustuberosusis
sensitivetoseawateratseedlingstage.
2 Materialsandmethods
2.1 Plantmaterialsandtreatments
HelianthustuberosustuberswereprovidedbyExperimentBaseof"863"inLaizhou,ShandongProvince.A sliceof
HelianthustuberosuswithabudwassurfacesterilizedwithHgCl2(1.0g/L)for10min,thenrinsedthoroughlywithdistiled
water,andgerminatedonmoistsandsforsomedaysinanincubatorat25ºC.Uniformgerminatedsliceswereselectedand
sowninplasticcontainersfiledwithquartzsand,grownintheglasshouseandwateredwithhalfstrengthHoaglandnutrient
solution.Whenthesixthleaffulyspread,slicesofplantswithuniformsizewereplantedintohydroponicsplasticpotsfitted
withinsulatedcovers.Eachpotwascoveredwithapolythenelidthroughwhichplantsweresupportedoverthenutrient
solution.Therewasoneplantineachpot.Thepotcontained400mLofhalfHoaglandnutrientsolution,whichwasaeratedfor
2hdailyandrenewedeveryotherdayextendedfor12d.Dailyphotoperiodwas12handmaximumtemperaturewas25℃ while
thedailyminimumtemperatureatnightwas15ºC.Therelativehumiditywas60%～70%.
Seawatertreatmentswereinitiatedbyaddingsalttothenutrientsolutionimmediatelyafterslicesweretransplantedtothe
nutrientsolution.Thesaltwasproducedbyevaporationfrom Laizhoubayseawater.ThebasicpropertiesofLaizhoubay
seawatercontainHCO-3 0.132g/L,Cl- 17.515g/L,SO2-4 3.867g/L,Ca2+ 0.785g/L,Mg2+ 1.027g/L,K+ 0.596g/L,
Na+ 9.480g/L.Fourtreatmentsweretheconcentrationsof0%(distiledwater),10%,25% and50% seawater.Every
2881 生 态 学 报 25卷
treatmenthadindependentexperimentwithsixreplicatesformeasuringthegrowth,inorganicandorganicosmoticas,
antioxidantenzymeandmembranceleakage.
2.2 Assaysoffreshweight,dryweight,waterandioncontentsofaerialpartsandroots
Freshplantsamplesobtained4,8and12daysafterseawatertreatmentwereusedforaerialpartsandrootsfreshweight
analysis.Theplantswereoven-driedat110℃ for10minandthendriedtoconstantweightat60℃.Thedrysampleswere
usedforanalysisofdryweight,contentofwaterinaerialpartsandroots.Contentofwaterwasdeterminedusingthefolowing
formula:W = (1- D/F)× 100%,hereW iscontentofwater,DisdryweightandFisfreshweight.
Drysamplesweremiledbeforeaciddigestionin1mL65% (V/V)ultrapurenitricacidat500℃ for6h.Concentrations
ofNa+ andK+ weremeasuredwithflameabsorptionspectrophotometry[7].ConcentrationsofCl- weredeterminedbytitration
withstandardsilvernitrateafter50mgdrysamplesweresteamedin20mLdistiledwaterat100℃ for45min[8].
2.3 Lipidperoxidationassays
TBA(thiobarbituricacid)testwasusedformeasuringlipidperoxidationinleaves.Thisdeterminedconcentrationsof
MDA(malondialdehyde)asanendproductoflipidperoxidation.Forthis,leaftissues(500mg)werehomogenisedin3mL
0.1% TCA(trichloroaceticacid)solution.Thehomogenatewascentrifugedat5000× gfor10minandthesupernatantwas
assayedforMDAconcentration[9].
2.4 Enzymeactivitiesassays
FreshleafsamplesofHelianthustuberosusseedlingsobtained4,8and12daysafterseawatertreatmentwereusedfor
enzymeactivitiesanalysis.Leaveswerefrozeninliquidnitrogenimmediatelyafterharvestingandstoredat-20℃ until
enzymeassays.Aportionofleafmaterial1gwasmixedin3mLof0.05mol/Lphosphatebuffer(pH7.8)including1mmol/
LEDTAand2% (W/V)PVP.Thehomogenatewerecentrifugedat10000×gfor15minat4℃.Supernatantwasusedfor
enzymeactivityandproteincontentassays.Alassaysweredoneat4℃.Alspectrophotometricanalyseswereconductedon
Shimadzu(UV-1600)spectrophotometer.
Superoxidedismutase(SOD)activityassaywasbasedonthemethodofGiannopolitisandRies[10],whichmeasuresthe
inhibitioninthephotochemicalreductionofnitrobluetetrazolium(NBT)spectrophotometricalyat560nm.Oneunitofenzyme
activitywasdefinedasthequantityofSODrequiredtoproducea50% inhibitionofreductionofNBTandthespecificenzyme
activitywasexpressedasunitsmg-1proteingFW.Thereactionmixturecontained50mmolphosphatebuffer(pH7.8),750
µmol/LNBT,130mmol/LL-methionine,0.1mmol/LEDTAand0.02mmol/Lriboflavin.Reactionswerecarriedoutat25
℃ underlightintensityofabout300µmol/(m·s)for15min.
Peroxidaseactivity(POD)wasbaseduponthemethodasdescribedbyHerzogandFahimi[11],whichmeasurestheincrease
inabsorbanceat460nm.TheincreaseinA460wasfolowedfor3min.To0.1mLoftheenzymeextract,asubstratemixture
containingacetatebuffer(0.1mol/L,pH5.4),ortho-dianisidine(0.25% inethylalcohol)and0.1mL0.75% H2O2was
added.Absorbancechangeofthebrownguaiacolat460nmwasrecordedforcalculatingPODactivity.Activitywasexpressed
asunits(µmolofH2O2decomposedperminute)permgofprotein.
Catalase(CAT)activitywasassayedusingthemethoddescribedbyAebi[12].Thereactionmixturecontained50mmol/L
phosphatebuffer(pH7.0),45mmol/LH2O2and100µLofenzymeextractina3mLvolume.Theactivitywasassayedby
monitoringthedecreaseinabsorbanceat240nmasaconsequenceofH2O2consumption.Activitywasexpressedasunits(µmol
ofH2O2decomposedperminute)permgofprotein.
Solubleproteinconcentrationinthedifferentextractswasmeasuredat660nm bythemethodofBradford[13]usingthe
Folin-Ciocalteaureagentwithbovine-serumalbuminasastandard.
2.5 Osmoticasubstanceassays
Prolinewasdeterminedinnoduleextractsusingninhydrinreagent.Forthecalculationofprolineconcentration,astandard
curvewaspreparedwithL-proline.AssayforsolublesugarsfolowedthecolorimetricmethodofIrigoyenetal[14].
2.6 Membranepermeabilityassays
ThemembranepermeabilitywasmeasuredbyusingelectricalconductivitymethoddescribedbyLiuetal[15].
2.7 Statisticalanalysis
Analysisofvariancewasperformedandstatisticalsignificance(p<0.05)ofdifferencesamongtreatmentmeanswas
38818期 隆小华 等:不同浓度海水对菊芋幼苗生长及生理生化特性的影响
judgedbyDuncansNewMultipleRangeTestusingSPSSsoftware(10.0).
3 Results
FW ofaerialpartsandrootsofHelianthusTuberosusseedlingsunder10% seawaterincreasedwithtimeandtherewereno
significantdifferencecomparedwith0% seawater(p<0.05)(Table1).WhileFW ofaerialpartsandrootstreatedwith25%
seawaterwerelowerthanthosetreatedwith0% seawater,andwere82% and87% ofthoseunder0% seawateronDay12,
respectively.Under50% seawater,FW ofaerialpartsandrootssignificantlydecreasedonDay12comparedtothoseonDay4,
andwereonly33.8% and27.0% ofthoseonDay4(Table1).ThetrendsofDW ofaerialpartsandrootsofHelianthus
TuberosusseedlingsresembledthoseofFW.DW ofaerialpartsandrootsalincreasedwiththeincreasinglevelofseawater
concentrations.Foralharvestdays,DW wassignificantlylowerunder50% seawatertreatmentcomparedwithother
treatments.LikeFW,DW ofaerialpartsandrootsunder50% seawateraldeclinedsharplyovertime.Forexample,DW of
aerialpartsandrootsonDay12wereonly45.8% and70.0% ofthoseonDay4(Table1).
Table1 Effectsofseawaterconcentrationsonfresh(FW)anddrybiomassweight(DW)ofaerialparts(AP)androots(R)ofHelianthus
tuberosusseedlings(g)
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
FW DW FW DW FW DW
AP R AP R AP R AP R AP R AP R
0 3.48aa) 3.30a 0.42a 0.19a 4.26a 4.35a 0.49a 0.25a 5.58a 5.03a 0.59a 0.33a
10 3.56a 3.54a 0.43a 0.20a 4.58a 4.68a 0.53a 0.26a 5.59a 4.96a 0.58a 0.32a
25 3.36a 3.65a 0.38a 0.21a 4.18a 4.23a 0.46a 0.25a 4.59b 4.37b 0.53a 0.30a
50 1.42b 1.59b 0.24b 0.10b 1.28b 1.12b 0.22b 0.11b 0.48c 0.43c 0.11b 0.07b
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththesameletterinthesamecolumnarenotsignificantly(p<0.05)differentby
DuncansNewMultipleRangeTest
Table2 Effectsofseawaterconcentrationsoncontentsofwaterin
aerialparts(AP)androots(R)ofHelianthustuberosusseedlings
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
AP R AP R AP R
0 87.93aa) 94.24a 88.50a 94.25a 89.43a93.44a
10 88.25a 94.36a 88.43a 94.44a 89.24a93.42a
25 89.33a 94.25a 89.00a 94.09a 88.46a93.14a
50 83.10b 93.71b 82.81b 90.18b 77.08b83.72b
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththe
sameletterinthesamecolumnarenotsignificantly(p< 0.05)
differentbyDuncansNewMultipleRangeTest.
ContentsofwaterinaerialpartsandrootsofHelianthus
tuberosusseedlingswithdifferenttreatmentswereshownin
Table2.Watercontentsofaerialpartsandrootsunder0%,
10% and25% seawaterdidntchangesignificantlyovertime.
Whilewatercontentschangedgreatlyunder50% seawater
overtime.WatercontentsonDay12wereonly92.8% and
89.3% ofthoseonDay4.
MembranelipidperoxidationinHelianthustuberosus
seedlingleaveswasassessedbycontentsofMDA(Fig.1).
Comparedtocontrol,MDA contentsunder10% seawater
werelowerthanthoseofthecontrolonDay8andDay12.
MDA contentsunder25% seawaterdeclinedon Day 12
comparedtothoseonDay8.Under50% seawater,MDAcontentswerehigherthanthoseofothertreatmentsonDay4,Day
8andDay12,andwere1.4,1.7and5.3timesofthoseofthecontrol,respectively.Withprolongedtreatment,contentsof
MDAonDay12increasedandwere2.98and2.01timesofthoseonDay4andDay8,respectively.
Table3showedthattheeffectsofseawaterconcentrationsonelectrolyticleakagepercentage(ELP)ofHelianthus
tuberosusseedlingsleaves.Comparedtothecontrol,ELPunder50% seawatersignificantlyincreasedonalsamplingdays.
Andovertimethetrendsweremoreobvious.Forexample,ELPofleavesunder50% seawaterreached31.56% and60.12%
onDay8andDay12,respectively.Theseresultsstronglysuggestthatleavescelsmembranepermeabilityincreased
significantlyunder50% seawater.
SODactivitiesofHelianthustuberosusseedlingleavesunderdifferentseawaterconcentrationswerealsoshowninFig.1.
SODactivitiesunder0%,10% and25% seawateralincreasedwithtime,andonDay12theactivitieswere1.1,1.6and1.9
timesofthoseonDay4,respectively.Furthermore,SODactivitiesunder25% seawaterwerehigherthanthoseof0% and
4881 生 态 学 报 25卷
10% seawater.OnDay12,SODactivitiesunder25% seawaterwere1.9timesforthecontroland1.4timesfor10% seawater
treatment.WhileSODactivitiesunder50% seawateronDay8werehigherthanthoseonDay4andDay12.Andtheydeclined
sharplyonDay12andwereonly41.6% ofthoseonDay8.
Table3 EffectofseawaterconcentrationsonELPofHelianthus
tuberosusseedlingsleaves(%)
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
0 4.99ca) 5.08b 5.20c
10 4.93c 5.01b 5.17c
25 5.44b 5.32b 6.03b
50 8.13a 31.56a 60.12a
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththe
sameletterinthesamecolumnarenotsignificantly(p< 0.05)
differentbyDuncansNewMultipleRangeTest
ThetrendsofPOD activitiesofHelianthustuberosus
seedlingleavesweresimilarunder10%,25% and50%
seawater.PODactivitiesonDay8under10%,25% and50%
seawaterwerehigherthanthoseonDay4andDay12.POD
activitiesofthecontrolonDay12werehigherthanthoseon
Day4andDay8.Buttheywerelowerthanthoseunder10%,
25% and50% seawateronDay12.PODactivitiesunder50%
seawaterwerehigherthanthoseofothertreatmentsonDay
4,Day8andDay12.Forinstance,PODactivitiesunder50%
seawaterwere50.0%,90.3% and59.0% higherthanthose
under 25% seawateron Day 4, Day 8 and Day 12,
respectively(Fig.1).
CATactivitiesofHelianthustuberosusseedlingleavesunder0%,10%,25% and50% seawateralincreasedovertime
(Fig.1).CATactivitiesunder0%,10%,25% and50% seawateronDay12were3.0,5.8,4.1and4.5timesofthoseon
Day4,respectively.CATactivitiesincreasedwithincreasingseawaterconcentration.CATactivitiesonday4under50%
seawaterwere16.2%,106.0%,17.7% higherthan0%,10% and25% seawater,respectively.CATactivitiesunder10%,
25% and50% seawateronDay8were105.3%,67.7%,19.1% higherthanthoseunder0% seawater,andonday12were
231.4%,59.6% and29.9% higherthanthoseunder0% seawater.
Fig.1 MDAcontents,SOD,PODandCATactivitiesinHelianthustuberosusseedlingleavesinresponsetoseawaterconcentrations.Data
representstheaverageofthreereplicates
ProlinecontentsinHelianthustuberosusseedlingleavesunderdifferenttreatmentsareshowninTable4.prolinecontents
58818期 隆小华 等:不同浓度海水对菊芋幼苗生长及生理生化特性的影响
under10%,25% and50% seawaterwerealhigherthanthoseunder0% seawateronDay4,Day8andDay12Furthermore,
itshowedasignificantincreaseinprolinecontentswithincreasingseawaterconcentration.Prolinecontentsunder50%
seawaterwere5.49,121.76and421.84timesofthoseunder0% seawaterrespectively.Prolinecontentsunder10% and25%
seawateronDay8werehigherthanthoseonDay4andDay12.However,prolinecontentsunder50% seawaterincreased
sharplyovertime.Liketheproline,soluble-sugarcontentsofHelianthustuberosusseedlingleavesrosewithseawater
concentrationsincreasing.Andsoluble-sugarcontentsunder10%,25% and50% seawateronDay8werehigherthanthoseon
Day4andDay12,andthoseonDay12declined60.4%,42.5% and39.4% ofthoseonDay8,respectively(Fig.2).
Fig.2 Soluble-sugarcontentsofHelianthustuberosusseedlingsin
responsetoseawaterconcentrations.Datarepresentstheaverageof
threereplicates
Table4 Effectsofseawaterconcentrationsonprolinecontentsin
leavesofHelianthustuberosusseedling(µg/gFW)
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
0 17.12da) 8.97d 5.20d
10 24.21c 41.64c 23.73c
25 41.72b 431.08b
233.
68b
50 94.07a 1092.17a 2193.53a
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththe
sameletterinthesamecolumnarenotsignificantly(p<0.05)
differentbyDuncansNewMultipleRangeTest
Na+ andK+ contentsinaerialpartsandrootsofHelianthustuberosusseedlingswithdifferenttreatmentsareshowninTable5.
Na+ contentsinaerialpartsandrootsrosesignificantlywithincreasingseawaterconcentrationandtimelasting.WhileK+
contentsinaerialpartsandrootsunder25% and50% seawaterdeclinedovertime.Under0% and10% seawater,theK+
contentsdidntchangesignificantly.
Table5 EffectsofseawaterconcentrationsonK+ andNa+ contentofaerialparts(AP)androots(R)ofHelianthustuberosusseedlings(mmol/
gDW)
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
K+ Na+ K+ Na+ K+ Na+
AP R AP R AP R AP R AP R AP R
0 1.24ca) 1.16c 0.05c 0.16d 1.12b 1.29b 0.06d 0.31d 1.04a 1.20b 0.07d 0.28d
10 1.44b 1.61a 0.17c 0.73c 1.20b 1.32b 0.41c 1.13c 1.05a 1.41a 0.55c 1.48c
25 1.61a 1.65a 0.71b 1.07b 1.33a 1.45a 1.05b 1.32b 1.12a 1.40a 1.29b 1.99b
50 1.28c 1.41b 0.96a 1.57a 0.91c 1.31b 1.27a 1.87a 0.45b 0.95c 1.69a 2.13a
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththesameletterinthesamecolumnarenotsignificantly(p<0.05)differentby
DuncansNewMultipleRangeTest
LikeNa+,Cl- contentsinaerialpartsandrootsrosesignificantlywiththeseawaterconcentrationsenhancing(Table6).
Cl- contentsinaerialpartsandrootsunder50% seawaterwere9and8times,8and6times,9and7timesofthoseunder0%
seawateronDay4,Day8andDay12,respectively.Andwiththetimelasting,Cl- contentsinaerialpartsandrootsincreased
under10%,25% and50% seawater.
4 Discussion
Salttoleranceofdifferentplantsanddifferentgrowthstagesofsameplantisdissimilarbecauseitisdecidedbytheir
transmissibilityoftheplant.Inthepresentstudy,thereweredistincteffectsof50% seawaterongrowthofHelianthus
tuberosusseedlings.Forexample,thenumberofleaves,growthofstem,leafandrootswererestricted.Itwaspossibly
becausethehighsaltconcentrationaffectedceldifferentiationandtherateofcelextension.Soluteinfiltrationincreasedwith
theaugmentofseawaterconcentration,whichreducedtheabsorptionofwaterandinducedthefalofwatercontentof
Helianthustuberosusseedlings.
6881 生 态 学 报 25卷
Table6 EffectsofseawaterconcentrationsonCl- contentsofaerial
parts(AP)androots(R)ofHelianthustuberosusseedlings(mmol/g
DW)
Seawater
concentration
(%)
Dayaftertreatment
4 8 12
AP R AP R AP R
0 0.21da) 0.27d 0.26c 0.37d 0.27d 0.31c
10 0.87c 1.06c 1.16b 1.70c 0.93c 2.06b
25 1.19b 1.66b 1.93a 2.02b 1.60b 2.26a
50 1.87a 2.07a 2.00a 2.31a 2.35a 2.27a
Dateareexpressedasmeans(n=3),a)Meansmarkedwiththe
sameletterinthesamecolumnarenotsignificantly(p< 0.05)
differentbyDuncansNewMultipleRangeTest
Oneeffectoffreeoxygenradicalsaccumulationinplant
celsunderstressislipid peroxidation via oxidation of
unsaturatedfattyacidsleadingtomembranedamageand
electrolyteleakage.Membranelipidperoxidationisthoughtto
beoneofthemostimportantmechanismsofsalttoxicityin
higherplants[16]. SOD, CAT and POD are the major
antioxidantenzymesassociatedwithscavengingtheactive
oxygenspecies(AOS)andSODislikelytobecentralinthe
defenceagainsttoxicAOS[17]. However,SOD detoxifies
superoxideanionfreeradicalsaccompanyingtheformationof
H2O2,whichisverydamagingtothechloroplasts,nucleic
acidsandproteins[18]andcanbeeliminatedbycatalaseand
peroxidase[19,20].
Inthepresentstudy,underthestressof50% seawater,contentsofMDA andELPwerehigherthanthoseofother
treatmentsonDay4,Day8andDay12,respectively,whichindicatedthatthemembraneconfigurationhadbeendestroyedin
asortofwayunder50% seawater.However,thelowercontentsofMDAunder25% seawateronDay12thanthoseonDay8
indicatedthatHelianthustuberosusseedlingshadadaptedwelpasttheinitialshockperiod.Comparedwithcontrol,therewas
nodamagetotheHelianthustuberosusseedlingsmembraneunder10% seawaterfromFig.1andTable3.Thisindicatesthat
Helianthustuberosusseedlingsmayhasahighhereditaryandinducedcapabilityunderseawaterwhichprovidesitabetter
protectionfrom oxidativedamagecausedbyseawater.Thisprotectionmightalsohavebeenduetosignificantlyhigh
constitutiveactivitiesofSODaswelasconstitutiveandinducedactivitiesofPOX,APOXandCATintheleavesofHelianthus
tuberosusseedlings.
Alantioxidantenzymeswerestimulatedinplantsexposedtosaltinthepresentstudy.Thismaybeageneraladaptive
defenceresponseofplantstotoxicsalineenvironmentsatearlystages.ItisnotedthattheinductionofSODactivitycoincided
withanincreaseintheactivityoftheenzymes(PODandCAT)scavengingH2O2[21].Bowleragreesthatthecooperation
betweenH2O2scavengingenzymesandSODplaysanimportantroleinresistanceofplantstoenvironmentalstresses[22].We
believethatsuchcoordinationalsoplaysacrucialroleinpreventingplantsfromsaltinjury.Theresultsofthisstudyshowthat
SODactivitiesincreasedwiththeaugmentofseawaterconcentration,whichmaybeageneraladaptivedefencemechanismof
plantstoseawaterenvironmentsatearlystages,althoughunder50% seawaterSODgradualylostactivityonDay12.PODis
amongtheenzymesthatscavengesH2O2inchloroplastswhichisproducedthroughdismutationofO-2 catalyzedbySOD[23].
IncreasedPODactivityhasalsobeenreportedinsalt-tolerantandsensitivespeciesoftomato[24]andricecultivars[25].POD
activitiesinthisstudyincreasedsignificantlywithincreasedseawaterconcentration.ThetrendsofPODactivitiesovertime
weresimilarunder10%,25%and50% seawater.CATactivitiestogetherwithSODarethemosteffectiveantioxidantenzymes
inpreventingcelulardamage[26].LikePODandSODactivitiesinthisstudy,CATactivitiesincreasedsignificantlywiththe
augmentofseawaterconcentrationandthetrendsofCATactivitiesovertimeweresimilarunder0%,10%,25% and50%
seawater.
Theaccumulationofsomeorganicsolutesundersalineconditionshasbeenconsideredasanadaptationofplantsagainst
osmoticstress.Amino-acidssuchasprolineandasparaginescanplayanimportantroleintheosmoticadjustmentoftheplant
undersalineconditions[27].Otherorganiccompoundsthataccumulateinresponsetostress,suchassolublesugars,apparently
playaroleinthedevelopmentofsalttolerance[28].Inaddition,plantspeciesadjusttohighsaltconcentrationsbylowering
tissueosmoticpotentialwiththeaccumulationofinorganicaswelasorganicsolutes[29].CationsNa+ andK+ andanionCl- are
knowntobethemajorinorganiccomponentsofosmoticpotential[30,31].InthisstudyprolinecontentsonDay8werehigher
thantheyonDay12withunder0%,10% and25% seawater,whileprolinecontentsunder50% seawaterstressincreased
sharplyduringtheexperimentalperiod.Infunction,prolineisoftenregardedasacompatibleosmoliteassociatedwiththesalt-
resistancemechanisms,andcanalsohelplowerthecelsosmoticpotential.Ourresultsrevealedsolublesugarcontentswith
differenttreatmentsincreasedearlieranddeclinedlaterduringtheexperimentalperiod,suggestingthatsolublesugarisan
78818期 隆小华 等:不同浓度海水对菊芋幼苗生长及生理生化特性的影响
organiccomponentofosmoticadjustmentduringtheinitialstagesofstress.Inthepresentstudy,Na+ andCl- contentsin
aerialpartsandrootsincreasedwithincreasedseawaterconcentration.Overtime,Na+ andCl- concentrationsalsoincreased.
Onthecontrary,K+ contentsinaerialpartsandrootsdeclinedwiththetimeandalsowithincreasedseawaterconcentration.
Thushighconcentrationofsaltsinseawatercanaffecttheabsorptionsofionsandincreasestheaccumulationoftheseionsand
thusmaketheminvolvedinosmoticadjustment.
TheresultsofthepresentstudystronglyindicatedthatHelianthustuberosuscouldadaptappropriateconcentration
seawaterirrigation through physiologicaland biochemicalmechanisms.In conclusion,ourresultsindicatethatlow
concentrationseawater,suchas10% and25% seawaterdidntdecreaseHelianthustuberosusseedlinggrowth,evenpromoted
growthduringtheexperimentalperiod.Ontheotherhand,higherSOD,POD,CATactivitiesandMDA,proline,soluble
sugar,Na+,K+ andCl- contentsunder10% and25% seawater,whichprobablycomefromanincreasedcapacityforoxygen
radicalscavengingandmaintenanceofcelularmembranesandosmoticadjustment,indicatedtherelationshipbetween
antioxidantdefenseandseawatertolerance.Furtherinvestigationsarenecessarytoputforwardtheeffectofseawaterbymeans
ofsubcelularcompartmentationofantioxidativeenzymeactivities,whichwouldbeausefultoolforourunderstandingof
seawaterstressandexplainingthesephenomena.Also,theresultsofthepresentstudycoupledwiththereportsinthe
literature[4] stronglysuggestthatHelianthustuberosuswithappropriateconcentrationseawaterirrigationiseffectiveand
secure.
References:
[1] LiangYC,ShenQR,ShenZG,etal.Effectsofsilicononsalinitytoleranceoftwobarleycultivars.J.PlantNutr.,1996,19:173～
183.
[2] FangS,ChenXL.Usingshalowsalinegroundwaterforirrigationandregulatingforsoilsalt-waterregime.IrrigationandDrainage
Systems,1997,11:1～14.
[3] JinM G.Temporalandspatialsoilwatermanagement:acasestudyintheHeilongjiangregion,PR China.AgriculturalWater
Management,1999,42(2):173～187.
[4] LiuZP,LiuL,ChenM D,etal.Studyontheirrigationsystemsinagriculturebyseawater.JournalofNaturalResources,2003,4:423
～429.
[5] RawsonHM,LongM J.GrowthanddevelopmentinNaCl-stressplant.Aust.J.PlantPhysi.,1988,15(4):519～540.
[6] ZhangBD.ThedevelopmentandplantingofHelianthustuberosus.ScienceandTechnologyofAgricultureinSichuan,1997,6(5):35～
37.
[7] YuBJ,LuoQY,LiuYL.EffectsofSaltStressonGrowthandIonicDistributionofSalt-bornGlycinesoja.ActaAgronomIcaSinica,
2001,27(6):776～780.
[8] HuntJ.Dilutehydrochloricacidextractionofplantmaterialforroutinecationanaslysis.Commun.inSoilSci.PlantAnal.,1982,13(1):
49～55.
[9] HeathRL,PackerL.PhotoperoxidationinisolatedchloroplastI.Kineticsandstoichemistryoffattyacidperoxidation.ArchBiochem.
Biophys.,1968,25:189～198.
[10] GiannopolitisCN,RiesSK.Superoxidedismutaseinhigherplants.PlantPhysiol.,1977,59:309～314.
[11] HerzogV,FahimiI.Determinationoftheactivityofperoxidase.Anal.Biochem,1973,55:554～562.
[12] AebiH.Catalaseinvitro.MethodsEnzymol.,1984,105:121～126.
[13] BradfordM M.Arapidandsensitivemethodforthequantitationofmicrogramquantitiesofproteinutilizingtheprincipleofprotein-dye
binding.Anal.Biochem.,1976,72:248～254.
[14] IrigoyenJJ,EmerichDW,Sanchez-DiazM.Waterstressinducedchangesinconcentrationsofprolineandtotalsolublesugarsin
nodulatedalfalfaplants.Physiol.Plant,1992,84:55～60.
[15] LiuHX,ZengSX,WangYR,etal.TheeffectoflowtemperatureonSuperoxidedismutaseinvariousorganelesofcucumberseedling
cotyledonwithdifferentcoldtolerance.ActaPhytophysiolSinica,1985,1:48～57.
[16] FadzilaNM,FinchRP,BurdonRH.Salinity,oxidativestressandantioxidantresponsesinshootculturesofrice.J.Exp.Bot.,
1997,48:325～331.
[17] MarschnerH.PartI.Nutritionalphysiology.In:MarschnerH(ed):MineralNutritionofHigherPlants.AcademicPress,London.
Seconded,1995,18(30):313～363.
8881 生 态 学 报 25卷
[18] FridovichI.BiologicaleffectsoftheSuperoxideradical.Arch.Biochem.Biophys.,1986,247:1～11.
[19] ScandaliosJG.Responseofplantantioxidantdefensegenestoenvironmentstress.Adv.Genet.,1990,28:1～41.
[20] ElstnerEF,OsswaldW.Mechanismsofoxygenactivationduringplantstress.ProceedingsoftheRoyalSocietyofEdinburgh,1994,
102:131～154.
[21] LiangYC,ChenQ,LiuQ,etal.Exogenoussilicon(Si)increasesantioxidantenzymeactivityandreduceslipidperoxidationinrootsof
salt-stressedbarley(HordeumvulgareL.).JournalofPlantPhysiology,2003,160(10):1157～1162.
[22] BowlerC,VanMontaguM,InzeD.Superoxidedismutaseandstresstolerance.Annu.Rev.PlantPhysiol.PlantMol.Biol.,1992,43:
83～116.
[23] BorM,OzdemirF,TurkanI.TheeffectofsaltstressonlipidperoxidationandantioxidantsinleavesofsugarbeetBetavulgarisL.and
wildbeetBetamaritimeL.PlantSci.,2003,164:77～84.
[24] ShalataA,TalM.Theeffectofsaltstressonlipidperoxidationandantioxidantsintheofthecultivatedtomatoanditswildsalt-tolerance
relativeLycopersiconpenneli.Physiol.Plant,1998,108:169～174.
[25] Dionisio-SeseM L,TobitaS.Antioxodantresponsesofriceseedingtosalinitystress.PlantSci.,1998,135:1～9.
[26] ScandaliosJG.Oxygenstressandsuperoxidedismutase.PlantPhysiol.,1993,101:7～12.
[27] GilbertGA,GadushM V,WilsonC,etal.AminoacidaccumulationinsinkandsourcetissuesofColeusblumeiBenthduringsalinity
stress.JExpBot,1998,49:107～114.
[28] HuY,SchmidhalterU.Spatialdistributionsofinorganicionsandsugarscontributingtoosmoticadjustmentintheelongatingwheatleaf
undersalinesoilconditions.Austr.J.PlantPhysiol.,1998,25:591～597.
[29] YangM S,LiYH,LianHY,etal.Iondistributionandcomparisoninseedlingsofwhitepoplarclonesundersaltstress.ActaEcologica
Sinica,2003,23(2):271～277.
[30] AschF,DingkuhnM,WittstockC,etal.Sodiumandpotassiumuptakeofricepaniclesasaffectedbysalinityandseasoninrelationto
yieldcomponents.PlantSoil,1999,207:133～145.
[31] XiaY,LinS,ZhangFS,etal.EffectoffoliarleachingongrowthandmineralnutrientcontentsofmaizeunderNaClstress.Acta
EcologicaSinica,2001,21(4):593～597.
参考文献:
[4] 刘兆普,刘玲,陈铭达,等.利用海水资源直接农业灌溉的研究.自然资源学报,2003,4:423～429.
[6] 张邦定.菊芋的开发与栽培.四川农业科技,1997,6(5):35～37.
[7] 於丙军,罗庆云,刘友良.盐胁迫对野生大豆生长和离子分布的影响.作物学报,2001,27(6):776～780.
[29] 杨敏生,李艳华,梁海永,等.盐胁迫下白杨无性系苗木体内离子分配及比较.生态学报,2003,23(2):271～277.
[31] 夏阳,林杉,张福锁,等.叶片淋洗对盐胁迫下玉米生长和矿质营养的影响研究.生态学报,2001,21(4):593～597.
98818期 隆小华 等:不同浓度海水对菊芋幼苗生长及生理生化特性的影响