小麦籽粒淀粉分支酶同工酶结构组成及时空表达

《小麦籽粒淀粉分支酶同工酶结构组成及时空表达》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、作物学报ACTAAGRONOMICASINICA2014,40(12):21762182http://zwxb.chinacrops.org/ISSN0496-3490;CODENTSHPA9E-mail:xbzw@chinajournal.net.cnDOI:10.3724/SP.J.1006.2014.02176小麦籽粒淀粉分支酶同工酶结构组成及时空表达112111,*刘正帅刘贵芬杨明煜贾晓李运祥赵法茂12泰山学院生物与酿酒工程学院,山东泰安271021;泰安市第一中学,山东泰安271000摘要:为阐明小麦支链淀粉合成的酶学机制,以8个小麦品种的籽粒为材料,采用非

2、变性聚丙烯酰胺凝胶电泳(Native-PAGE)和SDS聚丙烯酰胺凝胶电泳(SDS-PAGE)鉴定SBE同工酶类型、时空表达谱及亚基组成,分析SBE同工酶空间分布特点和器官表达特异性。共检测到4种SBE同工酶,其中B和SBEIIa分布在胚乳和叶片中,而A和Di专一定位于胚乳中。在小麦籽粒灌浆过程中,Di和SBEIIa首先表达,而后是B,A最后表达;至灌浆末期,B和SBEIIa停止表达。SBE同工酶都是单亚基酶,均由一条86~92kD的多肽链组成。SBE同工酶的空间分布具有器官特异性,并在籽粒发育进程中顺序表达。Di、B和SBEIIa是占主导地位的SBE同工酶,可能是决定

3、SBE总酶活性的主效应酶,在籽粒和叶片支链淀粉合成中起关键作用。关键词:小麦;淀粉分支酶;支链淀粉;时空表达;器官分布ConstitutionandSpatiotemporalExpressionofStarchBranchingEnzymeinDevelopingWheatGrain112111,*LIUZheng-Shuai,LIUGui-Fen,YANGMing-Yu,JIAXiao,LIYun-Xiang,andZHAOFa-Mao12CollegeofBiologyandEnology,TaishanUniversity,Tai’an271021,China;

4、Tai’anNo.1MiddleSchool,Tai’an271000,ChinaAbstract:Thisstudyaimedatdisclosingtheenzymaticmechanisminamylopectinsynthesisinwheat(TriticumaestivumL.).Theisozymeforms,organlocalization,spatiotemporalexpressionprofileandsubunitsconstitutionofstarchbranchingenzyme(SBE)wereidentifiedineightwhea

5、tcultivarsfromdifferentprovenancesusingnativepolyacrylamidegelelectrophoresis(Native-PAGE)andSDS-PAGE.FourSBEisozymesweredetectedinwheatendosperm,inwhichisozymesBandSBEIIawerelocalizedinen-dospermandleaf,whereasisozymesAandDiwereexclusivelypresentinendosperm.Intheprocessofgrainfilling,Di

6、andSBEIIaexpressedfirst,followedbyisozymeB,andisozymeAexpressedfinally.However,BandSBEIIaterminatedtoexpressatlatefillingstage.AllSBEisozymeswerecomposedofonesubunitof86–92kD,andtheirspatiallocalizationexhibitedorganspecificity.Accordingtotheexpressionlevel,Di,B,andSBEIIaareconsideredasd

7、ominantisozymesforgrainendospermde-velopment.TheyprobablydeterminatethetotalSBEactivityandserveaskeyfactorsinamylpectinbiosynthesisinwheatgrainandleaf.Keywords:TriticumaestivumL.;Starchbranchingenzyme;Amylpectin;Spatiotemporalexpression;Organlocalization淀粉是成熟小麦(Triticumae