Figure 7.

X-ray computed tomography images of differentiating xylem of Japanese cypress. A, Freeze-dried specimen. B, Washed specimen. In the freeze-dried specimen (A), coniferin was observed in differentiating xylem cells (arrows); however, coniferin disappeared at the stage of forming the S₃ layer (asterisks), where lignification of secondary walls occurred vigorously. Coniferin was not observed in the specimen prepared by washing (B). The previous study (Morikawa et al., 2010) confirmed that coniferin was contained in the residues.