Cloning Of CBF/DREB1 Of Caragana Korshinkii Kom And The Effect Of Its Overexpression On Drought And Cold Resistance Of Transgenic Arabidopsis Thaliana

Low temperature, drought and salt stresses are disadvantageous for the plants growth and development. Transcription factor DREB, which can bind specific core sequence of DRE element A/GCCGAC, can induce the downstream functional genes which have response to salt, drought and low temperature. Based on the importance of DREB in signaling, this dissertation analyzed the response of DREB1 gene to abiotic stresses using CkDREB1 overexpression transgenic lines, and the results showed:1. Three version of full-length DNA sequence of CkDREB were obtained from Caragana Korshinkii Kom. All the ORFs are 615bp in length. Sequence analysis showed that the conserved sequence such as PKK/RPAGRxKFxETRHP and DSAWR existed on the upstream and downstream of AP2 in CkDREB1 protein. Homology alignment indicated that CkDREB1 belonged to the A-1 subfamily of DREB protein family.2. Northern blot assay showed that CkDREB1 could be induced intensively by low temperature, and mildly induced by drought and ABA treatment, while not induced by high saline.3. The target gene expression level in all the CkDREB1 overexpression transgenic homozygous lines increased to different level, as detected by RT-PCR and Northern blot. After cold acclimination, the CkDREB1 overexpression plants are more resistant to freezing temperature that wild type control. Under drought treatment, the CkDREB1 transgenic homozygous plants also showed more resistant than wild type.