Genetically Transformed Strawberry (Fragaria x ananassa Duch.) with Cold-Inducible Transcription Factor CBF1

A foreign target-gene of cold-inducible transcription factor CBF1 (C-repeat binding factor) from Arabidopsis thaliana was introduced into strawberry by using the leaf-disc method via Agrobacterium tumefaciens. The transgenic plants were subjected to screening by Kan 25 mg/L, and then polymerase chain reaction (PCR) and Southern hybridization. The analysis of results indicated that the CBF1 gene integrated into the genome of strawberry. An analysis of physiological characteristics in terms of cold resistance was undertaken, based on methods of electrolyte leakage and restored growth. The results indicated that electrical conductivity of transgenic plants was lower than that of the control plant 'Toyonoka'. All transgenic plants and 'Toyonoka' were put in a temperature of -2 degrees C for 7 days and 60% of transgenic plants, whereas 85% of control plants wilted. Afterwards they were put in a temperature of 22 to 25 degrees C for restored growth. There, 44% of wilted transgenic plants and 30% of control plants were recovered. The introduction of CBF1 to strawberry may strengthen its resistance to the cold condition.