Cloning and Expression of Two MYB Transcription Factors in Tea Plant(Camellia sinensis)

(整期优先)网络出版时间:2012-03-13
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MYBtranscriptionfactorsrepresentafamilyofgenesthatincludetheconservedMYBDNA-bindingdomain,andtheyarewidelyinvolvedintheregulationofplantdevelopmentandsecondarymetabolism.Inthisstudy,PartofsequencesoftwoMYBtranscriptionfactorswasdeterminedthroughthecDNAmicroarrayhybridizationandselectionofcDNAlibraryderivedfromtendershoots.Thefull-lengthcDNAsofthegeneswereobtainedwithRT-PCRandRACE,andtheywere1132bpand1020bp,namedasCsMYB1andCsMYB2(GenBankaccessionNo.HQ660373andHQ660374),andcontainedORFsof879bpand675bpencoding292and224aminoacids,respectively.Sequencesanalysisshowedthatthededucedproteinmolecularweightofthetwogeneswere32.9kuand25.4ku,andtheproteinscontainedtwoconservedMYBdomainsneartheN-terminusandaconservedC1motifneartheR3domains.ThededucedaminoacidsequenceofCsMYB1andCsMYB2fromteaplantshowedhighidentitywiththatofotherplants,forinstanceCsMYB1shared57%homologywithMYB1ofGossypiumhirsutumandCsMYB2shared75%homologywithMYBC2ofVitisvinifera.Theresultofrealtime-PCRanalysisshowedthetwogeneswereexpressedconstitutivelyinalltissueswithdifferentexpressionlevels,e.g.therelativeexpressionlevelofCsMYB2inleafwashundredtimeshigherthanthatinroot.Additionally,shadingenhancedCsMYB1expression,whilethetreatmentdidnotaltertheexpressionlevelofCsMYB2.