Residual lignin, total sugar and uronic acid content of cell walls after 72 h of in vitro digestion. .Relative percentage of (A) residual lignin, (B) sugar and (C) uronic acid, which equal the percentage of lignin, sugar and uronic acid, respectively, remaining after 72 h of digestion relative to that of the control (control being 100%). Bars indicate standard error of mean (n = 3). *Differs to control at P 0.05. Apoplast (A), faeB-apoplast (average of 43A, 41A and 1A); endoplasmic reticulum (ER), faeB-ER (average of 24ER and 28ER); and vacuole (V), faeB-vacuole (average of 61 V, 15 V and 2 V). A, apoplast; ER, endoplasmic reticulum; V, vacuole; WT, wild type.