Abstract：Caragana intermedia is a pioneer species for wind-controlling and sand-fixing and distributes widely in arid and semi-arid desert area of north-west China. It has extremely strong resistance to stress and is a good feeding stock. A dehydration responsive element binding protein (DREB) transcription factor encoding gene has been isolated from the dought-treated transcriptome data set. In order to detect the drought and cold resistance of CiDREB1C, expression level of CiDREB1C gene under drought and cold in C. intermedia was detected by qRT-PCR. In order to identify the gene's function, the full length CiDREB1C (GenBank No. MG748598) were obtained through PCR, and was cloned into the expression vector pCanG-HA. Transgenic Arabidopsis thaliana had been obtained by Agrobacterium mediated genetic transformation, and the homozygous transgenic A. thaliana had been screened. The results showed that under mannitol treatment, the overexpression lines accumulated less malondialdehyde (P＜0.01), and had more chlorophyll compared with the wild type, showed obvious drought resistance phenotype. After cold treatment, the overexpression lines showed a significant increase in chlorophyll content compared with the wild type as well (P＜0.01). Under darkness treatment, the leaves of overexpression lines were greener than those of wild type, the cell death was less than that of wild type and the chlorophyll content was significantly higher than that of wild type (P＜0.01). These results suggested that overexpression of CiDREB1C could significantly increase tolerance of the transgenic A. thaliana to drought, cold and dark stress.The results of this research provide a theoretical basis for further analysis the function of CiDREB1C gene in stress resistance and the molecular mechanism of stress resistance of C. intermedia.
