Fig. 2.

Identification of plastid graft transfer events. (A) Grafted plant. Note that the P2 scion shown here is green because the expression of the bar^au gene is restricted to fast-growing tissue and is sensitive to environmental conditions. (B) Selection in cultures of 1–2-mm graft sections for gentamycin and spectinomycin resistance. On the left are stem sections from above (P2) and below (P1) the graft and on the right from the graft region. Note a green, proliferating callus that yielded the G4 PGT plants.