Inhibition of auxin-stimulated growth of pea stem segments by a specific nonasaccharide of xyloglucan.

Hemicellulose extracted from cell walls of suspension-cultured rose (Rosa "Paul's Scarlet") cells was digested with cellulase from Trichoderma viride. The quantitatively major oligosaccharide products, a nonasaccharide and a heptasaccharide derived from xyloglucan, were purified by gel permeation chromatography. The nonasaccharide was found to inhibit the 2,4-dichlorophenoxy-acetic-acid-induced elongation of etiolated pea (Pisum sativum) stem segments. This confirms an earlier report (York et al., 1984, Plant Physiol. 75, 295-297). The inhibition of elongation by the nonasaccharide showed a maximum at around 10(-9)M with higher and lower concentrations being less effective. The heptasaccharide did not significantly inhibit elongation at 10(-7)-10(-10)M and also did not affect the inhibition caused by the nonasaccharide when co-incubated with the latter.