Figure 1.

Effect of the xyloglucan oligomers XXLGol (a) and XXFGol (b) and of 2′-fucosyl-lactose (c) on the straight growth of wheat coleoptiles (A) and on the elongation promoted by 2,4-D (B). Two independent experiments, each conducted from 15 to 20 coleoptile segments treated or not with 2,4-D (1 μm) for 62 h were monitored and the mean increments of length (ΔL) were plotted. In A each value of a curve is the average of 30 to 40 experiments, and vertical bars represent ses. Data are presented as ΔL versus log sugar concentration; ΔL is the additional increase in length between 10 and 20 h. The absolute increase in length of controls (sets in the absence of 2,4-D or oligosaccharides) exhibited the mean value of 3.87 mm. This value was the reference (ΔL = 0). In B data are presented as mean percentages of inhibition or activation of 2,4-D-stimulated growth, calculated as percentages of activation or inhibition = L_{(2,4-D + oligosaccharide)} − (L_[2,4-D])/(L_[2,4-D]) − L_(control) × 100%, where L_(2,4-D) is the mean final length of segments treated with 2,4-D, L_(control) is the mean final length of segments incubated without 2,4-D, and L_{(2,4-D + oligosaccharide)} is the mean final length of segments treated with 2,4-D plus the oligosaccharide. Plotted data represent the means ± se.