Stability of luciferase gene expression in a long term period in transgenic eggplant, Solanum melongena

The luc gene, from firefly, was ligated into the multiple cloning site of the pBI121 plasmid and was then incorporated into Agrobacterium tumefaciens strain LBA4404. This vector containing a CaMV 35S promoter, a NOS terminator, a NPTII gene and a NOS promoter was used to transform 'Hibush' eggplant (Solanum melongena). Genomic DNA from the transformants was analyzed by assay of both PCR and southern blotting, which confirmed the presence of an expected luc fragment. Four transformants were chosen for an extended LUC assay. During the course of one year, LUC activity fluctuated, but was maintained at the initial activity even after 50 weeks. Expression of the luc gene in transgenic calli revealed that fluctuation of the LUC activity was due to changes in the environmental temperature. Luminescence from transgenic eggplant was detected using image analysis and light emission was found to be intense throughout the whole plant.