Occurrence of cello-oligosaccharides in the apoplast of auxin-treated pea stems

Treatment of pea (Pisum sativum L.) hypocotyl segments with indole-3-butyri c acid, which promotes segment elongation, increased the solubilization of both xyloglucan and cello-oligosaccharides in the apoplast of auxin-treated pea stems. The cello-oligosaccharides were isolated from the apoplastic so lution with a charcoal/Celite column and were identified as cellobiose, cel lotriose, and cellotetraose after subsequent thin-layer chromatography and paper electrophoresis. Cello-oligosaccharides in the apoplastic fraction we re monitored using cellobiose dehydrogenase. Both xyloglucan and cello-olig osaccharides appeared to be formed concurrently within 30 min after treatme nt with the auxin, and the cello-oligosaccharides increased with stem elong ation even after 2 h. The total activity of cellulase did not increase for up to 4 h.