Fucosylated high molecular mass but not non-fucosylated low molecular mass xyloglucans undergo an extensive depolymerization in cell walls of azuki bean epicotyls

摘要: Abstract Epicotyl cuttings of azuki bean were incubated with [14C]-glucose (Glc) or [3H]-fucose (Fuc), and the metabolism radiolabeled polymers in 24% KOH-extractable cell wall fraction was investigated. Applied 14C-Glc 3H-Fuc predominantly incorporated into glucan backbone Fuc residue xyloglucan molecules, respectively. On gel permeation chromatography, 14C-polymers consisted a main peak (0.7–1.0 MDa) shoulder (30 kDa). The pattern similar to that iodine-reactive xyloglucans fraction. other hand, 3H-polymers single eluted around 0.7–1.0 MDa. elution patterns 14C- constant during incubation period, although radioactivity increased time. In pulse-chase experiment, high molecular mass peaks both showed an extensive downshift, but not 14C-polymers. These results indicate consist two types molecules; fucosylated non-fucosylated low polymers. Azuki epicotyls may synthesize independently, only undergo active depolymerization wall.