Expression of Stig1 in petunia and tobacco wild-type, knockout, and transgenic plants. A, RNA gel-blot analysis of Stig1 transcript levels in developing stigmas of wild-type petunia plants, stages 1 to 10 (see “Materials and Methods”). Ten micrograms of total RNA was loaded in each lane. B, E, and F, Control for equal loading using a random-primed 32P radioactive-labeled 25S cDNA probe. C, RNA gel-blot analysis of Stig1 transcript levels in stigmas of wild-type (10 and 16) and petunia knockout (4 and 5) plants. Mutants carry the stabilized transposon in the Stig1 gene. Ten micrograms of total RNA was loaded in each lane. D, RNA gel-blot analysis of Stig1 transcript level in stigmas of wild-type, COS, and BAS transgenic tobacco plants. Ten micrograms of total RNA was loaded in each lane.