%0 Conference Paper
%F Oral 
%T 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
%+ Biologie intégrée pour la valorisation de la diversité des arbres et de la forêt (BioForA)
%+ Bois (BOIS)
%+ Centrale de Technologie en Micro et Nanoélectronique CTM-­LMCP
%A Laurans, Françoise
%A Arnould, Olivier
%A Capron, Marie
%A Ramonda, Michel
%A Almeras, Tancrede
%A Laine-Prade, Véronique
%A Secerovic, Amra
%A Déjardin, Annabelle
%A Pilate, Gilles
%< avec comité de lecture
%B XV Cell Wall Meeting
%C Cambridge, United Kingdom
%8 2019-07-07
%D 2019
%Z Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph]Conference papers
%X 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.
%G English
%L hal-02269060
%U https://hal.science/hal-02269060
%~ CNRS
%~ INRA
%~ LMGC
%~ AGREENIUM
%~ MIPS
%~ UNIV-MONTPELLIER
%~ INRAE
%~ BIOFORA
%~ INRAEVALDELOIRE
%~ UM-2015-2021