Table I.
GUS activity determination in protein extracts of leaf tissue harvested from tobacco plants containing different combinations of loci X, Y, and Z (Fig. 1)
| Genotype | GUS Activitya | No. of Plants Analyzedb |
|---|---|---|
| Units GUS mg−1 total soluble protein | ||
| X | Below detection | 1 |
| Y | 368 ± 165 | 9 |
| Z | 126 ± 30 | 10 |
| XY | 2 ± 1 | 4 |
| XZ | 139 ± 35 | 9 |
| YZ | 477 ± 101 | 10 |
| XYZc | 4 ± 3 | 22 |
a
Mean ± sd.
b
The axenically grown plants were analyzed 4 weeks after sowing on Murashige and Skoog medium supplemented with 1% (w/v) Suc in Falcon petri dishes (Becton Dickinson, Bedford, MA).
c
XYZ plants were grown in the presence of phosphinothricin (10 mg mL−1) and hygromycin (25 mg mL−1); under these conditions, both XYZ plants and YZ plants containing the pNE T-DNA (see “Materials and Methods”) were able to develop. A polymerase chain reaction with X-specific primers was performed to screen for the presence of X.