Figure 4.

Construction of the TGA2GAL4 Chimeric Transcription Factor and the UAS^GAL::GUS Reporter.

The bZIP domain of TGA2 (residues 47 to 94) was replaced by the DNA binding domain of the yeast GAL4 transcription factor (GAL4-DBD), and the resulting chimeric transcription factor was put under the control of the 35S promoter to generate 35S::TGA2GAL4. The GAL4-responsive reporter UAS^GAL::GUS was created by inserting the coding region of β-glucuronidase into plasmid pTA7001 (Aoyama and Chua, 1997) under the control of the synthetic promoter UAS^GAL, which contains the minimal 35S promoter sequence and six GAL4 binding sites. The plasmid (pGVG-GUS) carrying the UAS^GAL::GUS reporter also contains the chimeric transcription factor GVG, which consists of the DNA binding domain of GAL4 (GAL4-DBD), the activation domain of VP16 (VP16-AD), and the hormone binding domain of glucocorticoid receptor (GR-HBD).