Figure 10.

Transmission electron micrographs revealing the labeling of the 5-O-(transferuloyl)-l-arabinose (5-O-Fer-Ara) epitope on arabino-(1→4)-β-d-xylan during barley endosperm differentiation from 10 to 18 DAP. A, Immunogold-labeled section at the grain crease showing barely detectable levels of binding at 10 DAP. B, The central starchy endosperm at 10 DAP also shows little labeling on cell walls although gold particles bind to starch granules nonspecifically. C, Again at 12 DAP there is almost no detectable levels of the 5-O-Fer-Ara epitope at the grain crease. D, The aleurone cell walls that are beginning to differentiate (thicken) at 12 DAP are well labeled with the 5-O-Fer-Ara antibody. E, There is light labeling in the starchy endosperm at 12 DAP. F, No labeling was detected at the grain crease at 18 DAP. G, The aleurone cells are heavily and uniformly labeled throughout their thickened walls at 18 DAP. H, The starchy endosperm walls at 18 DAP are lightly and unevenly labeled with the 5-O-Fer-Ara antibody. Bar = 0.2 μm. al, Aleurone; cr, crease; cw, cell wall; se, starchy endosperm.