LOCALIZATION OF GLUCURONOXYLANS IN JAPANESE BEECH VISUALIZED BY IMMUNOGOLD LABELING

An antiserum against glucuronoxylans (GXs) has been raised from a mous e. The dot-blot immunoassay and competitive inhibition test indicated that the antibodies could bind specifically to GXs. Therefore, the ant iserum was used for immunogold labelling to investigate the localizati on of GXs in Japanese beech. Labelling of GXs was seen only in the sec ondary walls of xylem cells, but not in the primary walls or the middl e lamella. GXs were evenly distributed in the secondary walls except f or the outer part of the outer secondary-wall layer in which they were less abundant. The labelling density in each secondary-wall layer (S- 1, S-2, and S-3) increased during cell wall formation. This result str ongly suggests that the deposition of GXs occurs in a penetrative way.