Figure 4.

Basal Transcription in Maize Suspension Cells Is Stimulated by Wild-Type and Mutant TBP, but Not by TFIIB.

Basal transcription was tested with the minimal promoter–GUS reporter and the indicated effectors (10 μg of DNA each). The total amount of DNA used in bombardment for each treatment was kept constant for all combinations of effector and reporter DNAs. The promoterless–GUS reporter (Figure 3A, construct 2) served as a control for no transcription and was coexpressed with the null effector (bar 1). Experiments represented in bars 2 to 8 used the CaMV 35S minimal promoter–GUS vector (Figure 3A, construct 3). Activity is given as a ratio of GUS/LUC units and represents an average of triplicate experiments. Standard errors are indicated.