Glucocorticoid-induced expression of a foreign gene by the GVG system in transformed tobacco BY-2 cells

A glucocorticoid-induced target gene expression system was used to control the expression of the uidA gene, whose product was beta -glucuronidase (GUS ), in tobacco BY-2 cell suspension culture. This targeting system showed qu ick, sensitive, and reversible response to dexamethazone (DEX), an artifici al glucocorticoid hormone. Addition of DEX greatly and quickly enhanced uid A gene expression, whose level was as high as that under the control of the CaMV 35S promoter whereas in the absence of DEX, the GUS specific activity was suppressed to be as low as that of nontransformed BY-2 cells. The dilu tion of DEX decreased GUS specific activity showing that the concentration of DEX plays a major role in controlling the expression level of the target . The use of the glucocorticoid-induced system in plant cell suspension cul ture was demonstrated to precisely control target gene expression. (C) 2000 Elsevier Science S.A. All rights reserved.