T-DNA转移及整合的分子机制研究进展.pdf

维普资讯 遗 传 学 报 ActaGeneticaSinica，June2005，32 (6)：655～665 SSN0379—4172 ProgressonMolecularMechanism ofT-DNA Transportand Integration ZHAN Ya—Guang’① ZENG Fan—Suo ．XlN Ying ， (1．CollegeofLifeScience，NortheastForestryUniversity，Harbin 150040．Chma： 2．CollegeofForest，NortheastForestry Universiyt，Harbin 150040，China) Abstract：Agrobacterium—mediatedtransformationisprobablythemostwidelyusedmethodto introducegenes intoplants．Greatprogresshasbeenmade inrecentyearsinstudiesonthemechanism ofAgrobacterium—medi— atedtransformation．Agrobac~rium geneticallytransformsplantsbytransferringaportionoftheresidentTi—plas— mid，theT—DNA，totheplant．VirD2andVirE2accompanytheT—DNA into theplantcel1．Bothproteinsmayaid in T—DNA transfer，nucleartargetingand integration into theplantgenome．Inrecentyears，someArabidopsisrat (resistanttotransformation)mutantsaredeficientinT—DNA integrationaccordingtosomestudies．Thesere— suitsshowedthatplantgenesparticipateintheT—DNA transportandintegrationprocess．Thispaperdiscusses ourcurrentknowledgeaboutthefunctionsofvirulenceprotein，namelyVirD2andVirE2，andplantgenesinsev— eralaspectofAgrobacterium transformation．Thepaperdiscussestwo differentclassesofintegrationpatternsin detail：one isT—DNA rightborderbeinglinkedtogenomicsequencesbytheVirD2protein，theotherisT—DNA in— tegrationviaSDSA (synthesis—dependentstrand—annealing)．Accordingtothelateststudiesweelaboratedthe T—DNAintegrationmodelbasedongenomicDSB (double—strandbreaks)andproposedanew opinionabout themechanism ofT—DNA integration． Keywords：transgenicplants：proteinandnucleicacidtransfer；T—DNA integration