Conjugating immunolocalization and afm observations to determine if rhamnogalacturonan-i type pectins are responsible for the generation of maturation stress in poplar tension wood fibres
| Autor: | Laurans, Françoise, Arnould, Olivier, Capron, Marie, Ramonda, Michel, Almeras, Tancrede, Laine-Prade, Véronique, SECEROVIC, Amra, Déjardin, Annabelle, Pilate, Gilles |
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| Přispěvatelé: | Unité de recherche Amélioration, Génétique et Physiologie Forestières (UAGPF), Institut National de la Recherche Agronomique (INRA), Bois (BOIS), Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centrale de Technologie en Micro et Nanoélectronique CTM-LMCP, Université de Montpellier (UM), Biologie intégrée pour la valorisation de la diversité des Arbres et de la Forêt (BioForA), Office National des Forêts (ONF)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | XV Cell Wall Meeting XV Cell Wall Meeting, Jul 2019, Cambridge, United Kingdom |
| Popis: | International audience; Tension wood (TW) is produced by temperate hardwood trees in order to support theirincreasing weight, orient their axes and cope with environmental cues such as wind. Poplar TWfibres harbour a supplemental layer, the G-layer, rich in crystalline cellulose, containing matrixpolysaccharides but no lignin. The tensile force responsible for the specific mechanicalproperties of TW originates from the G-layer and is transmitted to cellulose microfibrils soonafter their deposition, during G-fibre maturation (Clair et al, 2011). This force is likely tooriginate from physical changes in the high porosity hydrogel recently identified in the G-layer.RG-I type pectins appear as good candidate molecules responsible for the formation of this gel.Indeed, during G-layer maturation, LM5 labelling (specific to RG-I side chains) decreased,while RU1 labelling (specific to RG-I backbone) increased (Guedes et al, 2017). This suggesteda hydrolysis of the RG-I side chains during G-fibre maturation possibly by a β-galactosidase asdemonstrated in flax phloem fibers (Roach et al, 2011). Flax phloem fibres and TW G-fibresexhibit many similar features and, in flax, it has been shown that the hydrolysis of the sidechains of RG-I type pectins was associated to the very peculiar mechanical properties of bastfibres.In order to determine if RG-I pectins were effectively involved in the building of the G-layertensile force, we carried out different measurements on a common sampling during G-fibredevelopment: i) β-galactosidase activities using a histochemical test, ii) the evolution of RG-Iimmunolabelling profiles using LM5 and RU1 as probes and iii) the stiffening of the differentcell wall layers using Atomic Force Microscopy (AFM). We found a good correlation betweenβ-galactosidase activities and RG-I immunological labelling but we failed to establish a directassociation between RG-I hydrolysis and cell wall stiffening. |
| Databáze: | OpenAIRE |
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