Regulation of a Highly Repeated GT Sequence from DCA1 Promoter of Dunaliella Salina in Salt-induction / 中国生物工程杂志

ABSTRACT

To identify whether a highly repeated GT sequence from DCA1 promoter from Dunaliella salina,which have been proved to be a salt-inducible promoter in our previous study,would be a salt-inducible regulation element,different primers were designed to amplify 6 different-length fragments of DCA1 promoter from D.salina by PCR.After these fragments were respectively inserted into the HindⅢ-BamH I sites of the vector pU?GUS,serial expression vectors containing the gus gene were generated.D.salina cells transformed with these recombinant plasmids by electroporation were grown in liquid media containing different concentrations of sodium chloride respectively.GUS enzyme activity was measured histochemically and fluorometrically.The results revealed that 3 fragments containing GT repeated sequence drove the external gus gene expression and the expression pattern of the gus gene was regulated by the concentrations of sodium chloride.Additionally,the 2 fragments without tandem GT sequence drove the gus gene expression,but the expression pattern of the gus gene wasn't regulated by the concentration of sodium chloride;Also,the upstream fragment of the tandem GT sequence wasn't able to drive the gus gene expression.In conclusion,the highly repeated GT sequence from the DCA1 promoter plays an important role in the salt-inducible regulation of DCA1 promoter from D.salina and might be a novel salt-inducible element.