Fig. 8

CP/MAS spectra and relaxation time constants of wall polysaccharides from celery collenchyma strands at four stages of development. Stage 1 (2-5 cm petioles), Stage 2 (10-15 cm petioles), Stage 3 (20-25 cm petioles), Stage 4( 35-40 cm petioles). a CP/MAS spectra of collenchyma cell walls with 65% (w/w) hydration. Gal/Glc C1, C-1 of galactose from galactans and glucose from cellulose; HG C1, C-1 of galacturonic acid from HG; iC4, C-4 of glucose from interior cellulose; sC4, C-4 of glucose from surface cellulose; HG C4, C-4 of galacturonic acid from HG. C2, 3, 5, carbon 2, 3, 5 of hexoses and galacturonic acid; HG C2, C-2 of galacturonic acid from HG; iC6, C-6 of cellulose from interior cellulose; sC6, C-6 of cellulose from surface cellulose. b Relative intensities of HG dominant signals from CP/MAS spectra, resulting from the absolute intensity of HG related signals divided by those of cellulosic signals at 105 ppm. Stage 1 (), Stage 2 (), Stage 3 (), Stage 4 (). c Representative relaxation pattern of T_1ρ^H and T₁^C from mainly cellulose at 89 ppm ( ) and HG at 69 ppm () in the collenchyma cell walls at Stage 4. d T_1ρ^H and T₁^C values of cellulose and HG in the collenchyma cell walls at different developmental stages. The chemical shifts beneath dashed line were clustered by cellulose (black line) and HG (red line). The dashed line set as guidance for comparison. Long and short components of the bi-exponentially decayed signals were shown as gray () and green () columns, respectively. The error bars were standard deviations from curve fitting using Origin software (see Methods)