Expression of the chemically inducible maize GST-27 promoter in potato

Chemically inducible gene regulation systems provide a mechanism for a temp oral control of expression of transgenes. In this study expression from the herbicide safener inducible maize GST-27 promoter was tested in potato, wi th the aim of using this to provide inducible expression of transgenes impl icated in dormancy control. A binary vector comprising 3.8 kb of the GST-27 promoter was fused to the beta -glucuronidase (GUS) reporter gene and tran sformed into potato. Application of the chemical inducer elevated the expre ssion of GUS up to 40 fold in leaf tissue. However in stems, roots and tube rs the GST-27 promoter caused high levels of expression of GUS in the absen ce of safener, demonstrating that in these tissues it acts as a constitutiv e promoter. A deleted promoter region of the GST-27 promoter displayed a si milar expression pattern. Analysis of GUS activity in dormant and sprouting tubers showed that the GST-27 promoter was a strong constitutive promoter throughout the tuber life cycle.