Ca-binding compounds in cell wall of peanut shell

Abstract

Ca compounds combined with the cell wall of the peanut shell were investigated by molecular sieve chromatography. The supernatant centrifuged after digestion of the cell wall by cellulase and the ligneous substances extracted with dimethylsulfoxide were loaded on a Sephadex gel column, respectively. In the former a part of Ca was eluted with the phenolic acids and carbohydrates, while in the latter Ca was eluted with lignin and the carbohydrates in the void volume. The major components of the phenolic acids were p-coumaric, caffeic, and ferulic acids. In the normal shell, the molar ratio of Ca to caffeic acid of the phenol-carbohydrate complexes was approximately 1, while in the Ca deficient shell the ratio decreased to about 0.7, mainIy due to an increase in the caffeic acid moiety of the complexes. In the cell wail of the peanut shell, the presence of a Ca chelate bridge more stable than ionic bonds was suggested.

Calcium and silicon binding compounds in cell walls of rice shoots

“…Although the forms of calcium and silicon in plants vary depending on the plant part and age, in this study, rice shoots, harvested at the panicle formation stage, were used to obtain a larger amount of ceilwall. Inanaga et al (1988) observed the release of calcium associated with the PCC from cell walls of peanut shells by cellulase action. When cell wall digests were loaded onto a Sephadex G-25 column, calcium and silicon were eluted together with phenolic acids and carbohydrate in the void volume (Fig.…”

“…Calcium in the PCC or LCC from the cell walls ofthe peanut shell may combine with caffeic acid but not with uronic acid (Inanaga et al 1988). However, no caffeic acid was detected in the cell walls of rice shoots (Table i), and calcium may combine with the hydroxyl-and carboxyl-groups of phenolic acids or uronic acid in the LCC.…”

“…The fact that silicon was extracted with acetate buffer and eluted in the void volume suggests that silicon may be present in a higher molecular form in the cell walls of rice shoots. The PCC obtained from the cell walls of the peanut shell (Inanaga et al 1988) or mature leaf blades of Lolium multiflorum (Hartly 1973) by cellulase action were derived from mixtures with a molecular weight ranging from a few thousands to over 200,000 or a few hundreds to over 50,000, respectively. On molecular-sieve chromatograms using Sephadex G-50, the concentrate was eluted in the void volume as symmetrical peaks with calcium, silicon, phenolic acids and carbohydrate, while on those using Sephadex G-200, calcium, phenolic acids, and carbohydrate except for silicon were eluted together from the fractions with higher to lower molecular weight.…”

“…The maintenance of the cell wall structure depends upon calcium cross-linkages, particularly with pectin components of the middle lamella (Bangerth 1979). In a previous paper (Inanaga et al 1988), we indicated that calcium may play an important role in the stability of the cell wall of the peanut shell through the formation of a calciumcomplex not only with pectin substances but also with the caffeic acid moiety in the LCC or PCC. Ito and Fujiwara (1968) reported that when the cell wall of rice leaf was fractionated, calcium was associated with ligneous substances.…”

Deep transcriptomic study reveals the role of cell wall biosynthesis and organization networks in the developing shell of peanut pod

“…Besides pectic compounds, Ca 2+ can form complexes in the cell wall of the peanut shell by crosslinking with lignin or carbohydrates via the phenolic acids and play a vital role in the stabilization of the cell wall [ 13 , 14 ]. Ca 2+ distribution was found to vary considerably during the development of peanut shells; higher in the pectin fraction at the beginning of enlargement (R5), an enlargement in the lignin fraction (R6), and at the expanded point (R7) in the cellulose fraction [ 15 ].…”