TISSUE-SPECIFIC ACTIVITY AND LIGHT-DEPENDENT REGULATION OF A SOYBEAN RBCS PROMOTER IN TRANSGENIC TOBACCO PLANTS MONITORED WITH THE FIREFLY LUCIFERASE GENE

The spacial and temporal promoter activity of the soybean rbcS gene SRS1 in transgenic tobacco plants was investigated. A 5'-fragment of the gene was fused to the coding region of the North American firefly luciferase (luc), to function as a reporter gene. The hybrid gene was introduced into Nicotiana tabacum by Agrobacterium-mediated leaf disk transformation and transgenic plants were regenerated. In planta and in vitro luciferase assays demonstrated that the activity of the soybean rbcS promoter in the heterologous tobacco background not only remained organ-specific, but was also stimulated by light. This is the first report demonstrating the suitability of the firefly luciferase reporter gene to investigate the temporal expression pattern of an environmentally stimulated plant gene.