Figure 1.

Differentiation of vascular-conducting cells in haustoria of Cuscuta japonica. Upper: In the prehaustorium, cells started elongating. CjWOX4, a procambium-specific gene, was not detected either by RT-PCR or in situ hybridization.⁸ Thus, it is unclear whether procambial cells are established (grey, left) or not (right) in the prehaustorium. Middle: between 48 and 72 h.a.a., before the onset of xylem vessel formation (white, left), procambial cells expressing CjWOX4 (grey, left) were established. This does not exclude the possibility that phloem and xylem has been differentiated. Lower: after 72 h.a.a., haustorial procambial cells differentiated into distinct phloem/procambial- and xylem domains. Solid line indicates the boundary of the prehaustorium. Dotted line indicates the boundary of the parasite, Cuscita japonica (Cj) and the host, Glycine max (Gm). Scale bar, 50 μm.