Figure 3.

Southern blots of EcoRV-digested DNA from transformant plants (lanes 1, 3, 4 and 5) probed with the 1,256-bp rbcL sequence (see “Materials and Methods” and Fig. 2). Results for control plants are shown in lanes 2 and 6. A, Plantlets after two rounds of regeneration. Lane 1 shows the results for the single heteroplasmic plantlet that retained the introduced EcoRV site. Lane 3 shows an example of the class of plantlets where loss of the EcoRV site had occurred, followed by sorting out to homoplasmicity. B, Lanes 4 and 5 show results for mature T₁ generation plants resulting from cloning and three additional rounds of regeneration of the plantlet analyzed in lane 1, followed by growth to maturity in soil, self-pollination of T₀ flowers, and growth of the resulting seed. Progeny of both original homoplastic plantlets derived from regeneration of the lane 1 plantlet are represented.