title: Characterization of tissue specific differences in cell wall polysaccharides of ripe and overripe pear fruit.
abstract: Cell walls from flesh, parenchyma cells, stone cells and skin were isolated from ripe and overripe Pyrus communis L. cv "De Cloche" using the phenol-buffer method. Pear polysaccharides were solubilized from cell walls by sequential extractions with aqueous solutions of ammonium oxalate, Na2CO3, and increasing concentration of NaOH, to explore overripening impact. Cell walls were also differentiated using MIR spectral data. Stone cells contained high levels of xylose and lignin while parenchyma cells had high levels of glucose, uronic acids and arabinose. Sequential extractions revealed that pear pectins had highly branched rhamnogalacturonans and were extremely methylated. Xylans were the main hemicelluloseespecially for stone cells. Cellulose represented about half of all cell walls. This heterogeneous composition of pear affected differently cell wall evolutions and properties. Thus, overripening involved a decrease in arabinose and a loss of pectic side chains mostly from parenchyma cells. Changes in hemicellulose and cellulose were minor.
authors.affiliation: UMR408 SQPOV, Sécurité et Qualité des Produits d'Origine Végétale, INRA, Avignon University, F-84000 Avignon, France. Electronic address: marwabrahem90@yahoo.fr.
authors.forename: Marwa
authors.initials: M
authors.lastname: Brahem
authors.affiliation: UMR408 SQPOV, Sécurité et Qualité des Produits d'Origine Végétale, INRA, Avignon University, F-84000 Avignon, France. Electronic address: catherine.renard@inra.fr.
authors.forename: Catherine M G C
authors.initials: CM
authors.lastname: Renard
authors.affiliation: UMR408 SQPOV, Sécurité et Qualité des Produits d'Origine Végétale, INRA, Avignon University, F-84000 Avignon, France. Electronic address: barbara.gouble@inra.fr.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gouble
authors.affiliation: UMR408 SQPOV, Sécurité et Qualité des Produits d'Origine Végétale, INRA, Avignon University, F-84000 Avignon, France. Electronic address: sylvie.bureau@inra.fr.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Bureau
authors.affiliation: UMR408 SQPOV, Sécurité et Qualité des Produits d'Origine Végétale, INRA, Avignon University, F-84000 Avignon, France. Electronic address: carine.le-bourvellec@inra.fr.
authors.forename: Carine
authors.initials: C
authors.lastname: Le Bourvellec
mesh_terms: D002473:Cell Wall / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D031989:Pyrus / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry
chemical_list: D011134:Polysaccharides; D014990:Xylans; D010368:Pectins
keywords: Cellulose; Hemicellulose; Lignin; Pectin; Pyrus communis L.; Sequential extraction