Figure 4

Experimental setup of C. japonica-G. max association. (A) A sampling schedule of the interface tissues at five parasitizing stages. Light and dark conditions are indicated by white and black areas, respectively. Just after attaching C. japonica to G. max stem, a G. max plant with C. japonica attached to its stem was placed under far red (FR) illumination and kept for 2 h. From 0 hour after attachment (haa) to 48 haa, a G. max plant with C. japonica attached to its stem was grown in the continuous dark [30]. The 48 haa-sample was harvested in the dark. From 48 haa to 120 haa, plants were grown in the 16 h/8 h light/dark condition. Black triangles indicate the time points of sampling. (B-F) Appearance of the interface region on the stem surface of G. max. IF, interface region; scale bars, 1 cm. (G-J) Cross sections of the interface region. Gm, G. max tissue; Cj, C. japonica tissue; vc, vascular cambium of G. max; h, haustorium of C. japonica. Scale bar, 10 μm. At 24 haa, a section of the interface region was not successfully made due to the weak adhesion of C. japonica to G. max. Note that, in panel H, haustorium (h) of C. japonica appears to penetrate the vascular cambium (vc) of G. max and the tip of haustorium reached the pith.