Cloning and function analysis of promoter of DcCDPK8 from Dendrobium catenatum
【Abstract】 DcCDPK8 is involved in abiotic stress such as low temperature stress and signal transduction of hormones ABA and MeJA, but the transcriptional regulation is still unclear. In order to study the core promoter region of DcCDPK8 gene in Dendrobium catenatum and explore its transcriptional regulation mechanism, the DcCDPK8 gene promoter sequence was cloned by PCR from D.catenatum. Promoter sequence function was studied by fusion of 5' terminal deletion and GUS gene. The results showed that the promoter sequence of DcCDPK8 gene has a low-temperature responsive element (LTR) between −1 749 bp and −614 bp, two MeJA responsive elements between −1 749 bp and −230 bp, and one ABA responsive element between −614 bp and −230 bp. Three 5'-end different deletion fragments were constructed to fuse the eukaryotic expression vectors p BI121 with GUS, which were transformed into tobacco leaves. The GUS activities under cold stress treatment were DcCDPK8-p1 > DcCDPK8-p2 > DcCDPK8-p3. GUS activities under exogenous ABA induction were DcCDPK8-p1 > DcCDPK8-p2 > DcCDPK8-p3, and GUS activities under exogenous MeJA induction were DcCDPK8-p1 > DcCDPK8-p2 > DcCDPK8-p3. It is speculated that the ABA response element (ARE) in the promoter sequences of DcCDPK8 plays a positive regulatory role in response to exogenous ABA, while the MeJA cis-acting element plays a negative role in response to exogenous MeJA.
【Keywords】 Dendrobium catenatum; DcCDPK8 promoter; transient transfection; histochemical staining;
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