Fig. 4.

Histochemical activity of β-glucuronidase (GUS) in transgenic plants: a–d 60-day-old transgenic tobacco plants belonging to lines Z4, Z5, and 35S, and wild-type (WT), respectively; e–k 30-day-old transgenic tobacco plants belonging to lines Z4, Z5, and 35S, and WT, respectively. In lines Z4, uidA is regulated by the promoter of Arabidopsis thaliana XYLOGEN PROTEIN 1; in lines 35S, uidA is regulated by the cauliflower mosaic virus 35S promoter; in lines Z5, uidA is regulated by the chimeric promoter 35S-Px. All the transgenic lines listed in Fig. 3 were stained and their representatives are shown here. Plants were stained in a buffer containing GUS substrate X-gluc (2 mg/mL) at 37 °C for 8 h