Light activation of expression associated with the tomato rbcS promoter in transformed tobacco cell line BY-2.

The promoter (2.3 kb) of ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (rbcS3B) from tomato was inserted into the upstream multi-cloning site of beta-glucuronidase (GUS) gene. The construction was introduced into the tobacco suspension cultured cell, BY-2. The transformed tobacco cell exhibited greater GUS activity (10-fold) under the light condition than the dark condition. The specific GUS activity increased with increasing culture time under the light condition. In fed-batch culture, high density culture was achieved, 47.6 g l-1 dry weight, which was 6.8-fold greater than the batch culture, whereas the GUS was produced 1.7-fold in specific activity compared with the batch culture. Growth of BY-2 and GUS gene expression during the culture were simulated by a kinetic model.