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

Abstract

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), Na2CO0 and KOH to leave the a-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 Na2C03 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 crosslink 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. INTRODUCTIONThe plant cell wall has a complex structure, with properties that depend on the tissue type and stage of development. The physical characteristics and biological functions of the cell walls depend primarily on the constituent structural polymers and how they interact with each other to form the wall matrix. The challenge is to identify the cell-wall polysaccharides, glycoproteins, proteoglycans and phenolics and understand how these are assembled in a particular cell type. Cell-wall models have been proposed based mainly on studies of suspensioncultured sycamore cells, which are deficient in polymers of the middle lamella [1,2]. In these studies exhaustive treatment with polygalacturonase was initially used, so that information on the composition and structure of some of the pectic polysaccharides would have been lost. In previous papers we have studied parenchyma cell walls from the pods of Phaseolus coccineus in some depth, but the pectic polysaccharides were degraded by the conditions of extraction used [3]. Nevertheless much information about the constituent glycoproteins [4,5], proteoglycans [6] and xyloglucans [7,8] has been obtained.We ha...

Cell wall polysaccharides of common beans (Phaseolus vulgaris L.)

“…These results are very coherent with the legume seed sugar compositions reported in the literature [11,15,19,20,25,27,33,37]. BHATTY [4] inferred that the lentil cell wall was probably composed of arabinan and arabinogalactan polysaccharides, because such polysaccharides are commonly distributed in the primary cell wall of cotyledonous plants.…”

An Arabidopsis Cell Wall Proteoglycan Consists of Pectin and Arabinoxylan Covalently Linked to an Arabinogalactan Protein

“…colleagues (Stevens and Selvendran, 1984;Ryden and Selvendran, 1990) systematically studied wall polysaccharides extracted from diverse tissues of different plants, including runner bean (Phaseolus coccineus), mung bean (Vigna radiata), cabbage (Brassica oleracea), and tomato (Solanum lycopersicum). Based on these studies, the authors suggested the presence of wall polysaccharide-protein and wall polysaccharide-polyphenol-Hyprich glycoprotein complexes in those plant tissues.…”

Participação dos polissacarídeos de parede celular no fenômeno de endurecimento de feijões (Phaseolus vulgaris L.) - cv Carioca-Pérola

“…Quantidades pequenas de xiloglicano foram encontradas em feijões, verificando-se, também, a presença de xilogalacturonanos e xilanos (RYDEN & SELVENDRAN, 1990;GOONERATNE et al, 1994 b ; MCDOUGALL & SELVENDRAN, 2001). …”

“…A literatura descreve a estrutura de parede celular de Phaseolus coccineus e Vigna radiata como sendo formada por pequenas quantidades de xiloglicanos e xilanos (RYDEN & SELVENDRAN, 1990;GOONERATNE et al, 1994 b ). É provável que este padrão também se repita em…”

“…Os dados sugerem a presença de arabinanos ramificados nas posições C-2 e C-3. O perfil de ligações encontrado em feijão é semelhante ao obtido por Gooneratne et al (1994 b ) em Vigna radiata e por Ryden e Selvendran (1990) em Phaseolus coccineus.…”