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1、西北植物学报,2008,28(10):2028-2034ActaBot.Boreal.-Occident.Sin.文章编号:1000-4025(2008)10-2028-07*外源NO提高小麦幼苗抗旱性的生理机制*赵翔,王棚涛,闻玉,张骁(河南大学生命科学学院河南省植物逆境生物学重点实验室,河南开封475001)摘要:以小麦(TriticumaestivumL.)品种-豫麦49.为材料,采用50Lmol#L-1SNP(NO供体)处理自然干旱和PEG模拟干旱下的小麦幼苗,分析外源NO对水分胁迫下小麦幼苗相对含水量、光合
2、速率、细胞膜透性以及茎叶中关键性离子含量的影响。结果显示:自然干旱10d后,对照组幼苗几乎全部枯死,而50Lmol#L-1SNP处理幼苗-1并未发生枯死,其幼苗在旱后复水2d后能完全恢复正常生长;在25%PEG-6000模拟干旱条件下,50Lmol#LSNP处理也能明显改善受胁迫小麦幼苗长势。50Lmol#L-1SNP处理使模拟干旱胁迫下小麦叶片的相对含水量显著提高15.98%,净光合速率(Pn)、气孔导度(Gs)分别显著提高47.11%和42.86%,而胞间CO2浓度(Ci)显著降低了8.19%;也使小麦组织浸出液
3、电导率显著降低30%,茎叶的K+含量显著增加24.55%(P<0.01)。研究发现,外源NO既可通过降低小麦幼苗叶片蒸腾来维持较高的叶片相对含水量,缓解因干旱缺水对植株的伤害;又可增加K+在茎叶中积累,减轻干旱胁迫对小麦幼苗细胞膜伤害,维持干旱胁迫下小麦幼苗较高的光合速率,以确保植株正常生长和有机物质积累。关键词:一氧化氮;小麦;水分胁迫;抗旱性中图分类号:Q945.78文献标识码:AMechanismofExogenousNitricOxideEnhancingDrought-ResistanceofWheatSe
4、edlings*ZHAOXiang,WANGPeng-tao,WENYu,ZHANGXiao(He.nanKeyLaboratoryofPlantStressBiology/SchoolofLifeSciences,He.nanUniversity,Kaifeng,He.nan475001,China)-1Abstract:Wheat(TriticumaestivumL.)variety,-Yumai49.seedlingsweretreatedwith50Lmol#LSNP(NOdonor)underdrought
5、stressormimicdroughtstress.Theeffectofexogenousnitricoxide(NO)onrelativewatercontent,photosyntheticrat,permeabilityofcellmembranesandcontentsofthekeyionas+Kwereinvestigatedinwheatseedlingsunderwaterstress.After10dofdroughtstress,thewheatseed--1lingspretreatedwi
6、thwaterascontrol,werealmostdead,butwhichpretreatedwith50Lmol#LSNPgrewbetter.Thelatterfullyreturntonormalgrowthaftertheresumptionofwaterfor2d;Inexperimentsof25%PEG-6000mimicdroughtstress,thesimilarresultswereobtained.Thetreatmentwith50Lmol#-1LSNPincreasedtheRWCo
7、fwheatleavesby15.98%.Thetranspirationratewasdecreaseda45%with-1SNPtreatmentatthesameanalyzedtime.Inaddition,thetreatmentwith50Lmol#LSNPincreasedthenetphotosyntheticrate(Pn)andstomatalconductance(Gs)by47.11%and42.86%respectively,butin-tercellularCO2concentration
8、(Ci)wasdecreasedby8.19%,comparedwith25%PEG-6000treatment.Therelativeelectrolyticleakage,acellinjuryindex,was30%lowerinSNP-treatedwheatseedlingsthanthat*收稿日期:2008-05-05;修改稿收到
