Cloning Of CBF 3 And Rd29A Gene Promoters From Arabidopsis Thaliana And Its Activity Detection In Transgenic Tobacco

The promoters of CBF 3 and rd29A are two stress-induciable promoters in higher plnat.The expression of CBF 3 and rd29A in Arabidopsis thaliana is induced by drought,cold and high salt stress.Therefore,the promoters are these(?)wo genes potentially important induced promoters in genetic engineering of plant for stress resistance.CBF 3 gene encodes a transcriptional activator,which specificly binds to the DRE,DRE contains cluster of COR genes,which are activated via the over expression of CBF 3 gene.The rd29A and CBF 3 response to drought,cold and high salt stress.The promoter of rd29A contains DRE and ABRE. CBF 3 and rd29A are very important in response to the stress signal transduction.In order to further understand the functions of the promoters of CBF 3 and rd29A,coldinduciable promoters CBF 3(C-repeat binding factor) and rd29A were amplified and cloned by PCR from the genomic DNA of Arabidopsis thaliana.The 35S promoter of vector pBI121 was replaced by promoters CBF 3 and rd29A,thus vectors pBC-GUS and pBC-GUS were constructed and transferred into tobacco by co-culturing excised cotyledon explants with Agrobacterium tumefaciens,and transgenic plants were tested by PCR and GUS histochemical stain,the results showed that promoter CBF 3 and rd29A were induced by low temperature stress,and strengthened the expression of the genes.Therefore,promoter CBF 3 could be used to plant gene engineering for cold resistance initiation.