Digital subtraction of the average spectrum representing the control plant cell walls minus that of B-deficient
plant cell walls constituted a digital spectrum, in which carbohydrate content was relatively enriched in the B-deficient plant cell walls because the characteristic peaks of polysaccharides (1153,1080, and 1020 cm−1) were enhanced. The positively correlated peaks at 1641 and 1543 cm−1 indicated that the protein content of the control plant cell walls was greater than that in the B-deficient plant cell walls (Fig. 7b).