Figure 3

Selection and regeneration of transformed callus. White light (A, C, E, G, and I) and UV illuminated (B, D, F, H, and J) P. aegyptiaca tissues showing YFP fluorescence. A and B) in vitro callus of P. aegyptiaca expressing a small sector of YFP on day 35 after transformation. C and D) chimeric transgenic P. aegyptiaca on day 90 after transformation. YFP-negative tissue was cut away and the YFP- positive tissue subjected to clonal propagation resulting in homogeneus transgenic calli seen in E and F. E and F) clonally propagated calli used for tomato inoculation on day 120 after transformation. G and H) tomato inoculation with excised explants from the transgenic calli. YFP-positive and negative parasitic roots were inoculated next to each other to show the absence of fluorescence in tomato roots and YFP-negative explants. I and J) Detail image of tomato host root parasitized by P. aegyptiaca explants from both sides. The wedge-shaped haustoria penetrating the host root are visible through the intact tomato living tissue. Ph YFP+, P. aegyptiaca positive expressing YFP; Ph YFP-, P. aegyptiaca negative control; Tom, tomato root; Ha, YFP positive haustoria.