Figure 3.

Transgene integration and expression in tobacco. Lane 1, Wild type; lane 2, transgenic p35S control; lanes 3 to 9, transgenic p35S-SMT2 lines A, B, C, D, E, F, and G, respectively. A, Internal 0.9-kb fragment of the Arabidopsis cDNA encoding SMT2 cloned into the T-DNA of the plant-transformation vector was amplified from chromosomal DNA of primary transformants. B, Total leaf RNA subjected to a RT-PCR reaction using primers specific to the 0.9-kb internal fragment of the Arabidopsis cDNA encoding SMT2. C, Ethidium bromide-stained gel showing equal amounts of total RNA used in B. D, Southern hybridization of the PCR products obtained as described in B with a ³²P-radiolabeled SMT2 probe. The arrows denote the size of the expected and obtained PCR products.