Fig. 3.

Quantitative analysis of cell wall polysaccharide compositions, neutral sugars, and uronic acid contents. A, determination of the relative amounts of pectin, hemicellulose, cellulose, and other unidentified components (Others) from cell wall materials of 10-dpa cotton fibers (F-10) or ovules (O-10) of wild type (WT) and the fl mutant (FL). **, significant at p < 0.01. Error bars indicate standard deviations. B, GC/MS separation and identification of neutral sugars. Thoroughly hydrolyzed and alditol acetate-derivatized non-cellulose cell wall polymers isolated from 10-dpa fiber cells (WT-F-10; upper panel) and ovules harvested at 10 dpa (FL-O-10 and WT-O-10; middle and lower panels, respectively) were analyzed by GC/MS. Inositol (Ino) was added at the time of extraction as an internal control. The spectra represent results obtained from three independent experiments using different cotton materials. Ara, arabinose; Man, mannose; Glc, glucose; Gal, galactose. C, GC/MS analysis of neutral sugars from purified pectin (FB-10-Pectin; upper panel) and hemicelluloses (FB-10-Hemicellulose; lower panel) using 10-dpa fiber cell wall isolations. D, GC/MS analysis of uronic acid composition in non-cellulose cell wall fractions. The entire experiment was repeated three times using independent cotton materials, and the data are reported at the top of each corresponding peak as mean ± S.E. (mg/g of cell wall).