Cell-wall polysaccharides and glycoproteins of parenchymatous tissues of runner bean (Phaseolus coccineus). Biochem J

A.F.R.C. Institute of Food Research, Norwich Laboratory, U.K.
Biochemical Journal (Impact Factor: 4.4). 08/1990; 269(2):393-402. DOI: 10.1042/bj2690393
Source: PubMed


1. Polymers were solubilized from the cell walls of parenchyma from mature runner-bean pods with minimum degradation by successive extractions with cyclohexane-trans-1,2-diamine-NNN'N'-tetra-acetate (CDTA), Na2CO3 and KOH to leave the alpha-cellulose residue, which contained cross-linked pectic polysaccharides and Hyp-rich glycoproteins. These were solubilized with chlorite/acetic acid and cellulase. The polymers were fractionated by anion-exchange chromatography, and fractions were subjected to methylation analysis. 2. The pectic polysaccharides differed in their ease of extraction, and a small proportion were highly cross-linked. The bulk of the pectic polysaccharides solubilized by CDTA and Na2CO3 were less branched than those solubilized by KOH. There was good evidence that most of the pectic polysaccharides were not degraded during extraction. 3. The protein-containing fractions included Hyp-rich and Hyp-poor glycoproteins associated with easily extractable pectic polysaccharides, Hyp-rich glycoproteins solubilized with 4M-KOH+borate, the bulk of which were not associated with pectic polysaccharides, and highly cross-linked Hyp-rich glycoproteins. 4. Isodityrosine was not detected, suggesting that it does not have a (major) cross-linking role in these walls. Instead, it is suggested that phenolics, presumably linked to C-5 of 3,5-linked Araf residues of Hyp-rich glycoproteins, serve to cross-link some of the polymers. 5. There were two main types of xyloglucan, with different degrees of branching. The bulk of the less branched xyloglucans were solubilized by more-concentrated alkali. The anomeric configurations of the sugars in one of the highly branched xyloglucans were determined by 13C-n.m.r. spectroscopy. 6. The structural features of the cell-wall polymers and complexes are discussed in relation to the structure of the cell walls of parenchyma tissues.

Download full-text


Available from: Peter Ryden,
  • Source
    • "Most of the uronic acids were extracted in the hot-water fraction. Polysaccharides obtained in the hot-water fraction were likely to be derived from the middle lamella of cell walls, as reported previously in other plant species (Ryden and Selvendran 1990). These pectic polysaccharides were readily degraded, thus affording fragments rich in neutral sugars and derived from pectin side chains (Femenia et al. 1998). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Analysis of cell wall polysaccharide composition of embryogenic and non-embryogenic calli obtained from hypocotyl and petiole explants from Medicago arborea L. revealed significant differences. For calli induced from both hypocotyls and petioles, levels of total sugars, pectins, and hemicelluloses were higher in embryogenic than in non-embryogenic calli. Whereas in the residual cellulose fraction, the highest levels of sugar were detected in non-embryogenic calli. When comparing the two donor sources of callus explants, the highest total sugar levels were detected in embryogenic calli induced from petioles, mainly in the pectin fraction and to a lesser extent in the hemicellulose fraction. Moreover, analysis of uronic acids revealed higher levels in embryogenic calli, primarily in the pectin fraction. Analysis of those sugars associated with cell walls of calli suggested that these polysaccharides consisted of pectic polysaccharides and glucans, and that their levels were higher in embryogenic than non-embryogenic calli.
    Plant Cell Tissue and Organ Culture 06/2009; 97(3):323-329. DOI:10.1007/s11240-009-9531-0 · 2.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Deficiencies in the widely used Hakomori method of methylation are described. Evidence is given that this method of linkage analysis often gives levels of undermethylation which hamper the detailed study of complex carbohydrates from plant cell walls. A modified method using sodium hydroxide as base is described which is capable of fully methylating polymers for which the Hakomori method generally fails and which does not promote the carbohydrate oxidation typical of a former procedure using this reagent. An explanation of its efficacy is advanced. Analyses of retrograded, α-amylase-resistant starches obtained by the modified method are reported.
    Phytochemical Analysis 09/1993; 4(5):210 - 216. DOI:10.1002/pca.2800040504 · 2.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pectins and hemicelluloses were extracted sequentially from the alcohol insoluble residue (AIR) of pea hulls using chemical agents. The AIR was rich in carbohydrates (942 mg g−1), notably cellulosic glucose, and was poorly lignified (6 mg g−1). Approximately 4 and 6% of the AIR could be sequentially extracted using CDTA and HCl (CSP and HSP respectively). After such depectination treatments, 4, 6 and 4% of the AIR were extracted by increasing concentrations of KOH (0·05 m (OHSP-I), 1 m (1OH-I) & 4 m (4OH-I), respectively). By contrast, alkali treatments alone (KOH 0·05 m (OHSP-II), 1 m (1OH-II) & 4 m (4OH-II)) extracted 2, 4 and 5% of the AIR, respectively. Hemicelluloses extracted by 1 m and 4 m KOH in both series were further fractionated through precipitation, upon neutralization of the extracts. Precipitates accounted for 82, 60, 74 and 60% of total hemicelluloses in the 1OH-I, 4OH-I, 1OH-II & 4OH-II extracts respectively, and appreared to be essentially pure, acidic xylans. More variation was seen in the composition of the soluble polymers, which were rich in xylose, glucose and uronic acids. Extracts were fractionated on Sephacryl S500 and DEAE Sepharose CL-6B. In the ‘pectic’ fractions, high molecular weight arabinans were found in HSP as well as xylose-rich polymers. Concentrated alkalis extracted small amounts of low molecular weight pectic material, but only after prior depectination had been carried out. The final residue accounted for around 61% of the AIR after depectination and alkali treatment, and contained 91% cellulose; after alkali treatment alone, it accounted for about 84% of the AIR and was rich in glucose (∼70%) and uronic acids (∼16%).
    Carbohydrate Polymers 01/1994; 24(2-24):139-148. DOI:10.1016/0144-8617(94)90024-8 · 4.07 Impact Factor
Show more