Fig. 3

Histochemical assays of GUS gene expression in transgenic tobacco seedlings, leaves, roots, and stems. N. benthamiana plants transformed with the pINT SP1 (1), pINT-FLt-US (2), pINT121 (3) or pINT-35SΔ (4, negative control) vector were used in these assays. Expression of the GUS gene was determined by overnight staining of tissues using 1 mM X-Gluc staining solution. A Images of seedlings representing the four different transgenic plant lines are shown. B Images of fully expanded leaves harvested from different transgenic plants and stained for GUS activity. C Images of roots harvested from different transgenic plants and stained for GUS activity. D Images of stem cross sections prepared from different transgenic plants and stained for GUS activity