Figure 5.

Effect of the DP (a) and reducing-end derivatization (b) of oligogalacturonides on their ability to induce extracellular alkalinization by suspension-cultured cv Samsun cells. The data were plotted as the alkalinization response of each sample divided by the alkalinization response induced by a saturating concentration of G₁₂ in that experiment (R/R_max). The R/R_max values for the various oligogalacturonides are indicated as follows: G₁₂, ▴; G₁₃, ▪; G₁₅, •; G₉, ♦; G₁₃-T, ⋄; G₁₃-B, □; G₁₃-O, ○; and G₁₃-R, ▵. The data for G₁₂ and G₁₃ are shown on both plots to aid in comparison. The lines represent the linear portion of the dose-response curves as determined by least-squares analysis using log concentration. Separate dose-response curves were generated using combined data from G₁₂ and G₁₃ and combined data from the four reducing-end derivatives of G₁₃ (see text).