非生物脅迫對R2R3MYB轉(zhuǎn)錄因子表達的影響

非生物脅迫對R2R3-StyleMYB

轉(zhuǎn)錄因子表達的影響R2R3-typeMYB的結(jié)構(gòu)特征Plantmeterialandstresstreatments

Tobacco(Nicotianatabacum)weresownonMSmediumandincubatedat25inagrowthchamberundera16/8-hlight/dardregime.One-month-oldtrifoliteorangeseedingswereusedfortreatmentswithabioticstresses,includingdehydration,lowtemperature,NaCl,andexogenousABAtreatment.1dehydrationstress：theseedingswereputondryfilterpaperfor0,0.5,1,3,and6h.2slattreatment:theseedingswereplacedin200mMNaClsolutionfor0,6,12,24,72,and144h.3coldstress:theseedingswereincubatedat4for0,6,12,24,72,and144h.4ABAtreatment:heseedingswereincubatedin100μMABAsolutionfor0,6,12,24,and48h.試驗處理實驗結(jié)果PtsrMYBislocalizedinthenucleusOverexpressionofPtsrMYBenhancesdehydrationtoleranceintransgenictobacco.(A)TranscriptlevelsofPtsrMYBinthetransgenicplants(#1,#7,#27,#29,#39).Ubiqutinwasusedasaninternalcontrolfornormalizingtheexpressionlevels.(B)RelativewaterlossrateofWTandtransgeniclines(#27and#39)underdehydration,measuredat10-minintervalsforupto60min(C)MDAlevelsofWTandtransgeniclines(#27and#39)beforeandafterdehydrationEctopicexpressionofPtsrMYBenhanceddehydrationtolerance

intobaccoADCgeneexpressionandfreepolyaminelevelswereincreased

inthetransgenicplants

Accumulationofreactiveoxygenspecies(ROS)wasreducedin

thetransgenicplantsafterdehydrationstressAnalysisoftheinteractionbetweenPtsrMYBandPtADCpromoter.(A)TheputativeMYBbindingsitesinthethreepromoterfragments(P1,P2,andP3)ofPtADC.(B)Schematicdiagramsoftheeffector(pAbAi-PtsrMYB)andreportervectorpGADT7-pPtADC1/pPtADC2/pPtADC3.(C)Growthofyeast(strainY1HGold)cellscotransformedwiththeeffectorplasmidandthereporte