Genetic transformation of flue-cured tobacco cultivars G28 and K326 protecting to cucumber mosaic virus

Two flue cured tobacco cultivars, G28 and K326, from Guangdong,were transformed by CMV BS CP gene from diseased banana via Agrobacterium tumefaciens , and 313 transgenic tobacco plants were obtained. Calli were observed on the small square sections of leaves of the transgenic plants in culture medium containing 100 g/mL Km,indicating the Km resistant marker genes (NPTⅡ) has been successfully introduced into the plants. It was confirmed with PCR analysis and DAS ELISA assay that the CMV BS CP genes were stably integrated into the genomes of the transgenic tobacco plants, and were subsequently found to be expressed in these plants. The transgenic tobacco plants were inoculated mechanically or by aphids with the hallenging CMV strains BS,27 and 37 from diseased banana,tobacco and cucumber in Guangdong,respectively. The transgenic tobacco plants expressing coat protein of BS were demonstrated protecting effect to the infection of these CMV strains significantly, delaying the disease expression and reducing