Xyloforest portal    
 Français English
Xylobiotech technical facilities : forest biotechnology
ArbreBois

Guedes et al. (2017) - Scientific paper - Formation of tension wood in poplar

Non-cellulosic polysaccharide distribution during G-layer formation in poplar tension wood fibers: abundance of rhamnogalacturonan I and arabinogalactan proteins but no evidence of xyloglucan

Planta 246 (5): 857-878. doi: 10.1007/s00425-017-2737-1

Guedes FTP, Laurans F, Quemener B, Assor C, Lainé-Prade V, Boizot N, Vigouroux J, Lesage-Descauses M-C, Leplé J-C, Déjardin A, Pilate G

INRA (AGPF, BIA, IATE) production
Collaboration France-Brazil

Technical support XYLOBIOTECH:

Reverse genetics

Confocal microscopy

Imager Pxi

Main conclusion

RG-I and AGP, but not XG, are associated to the building of the peculiar mechanical properties of tension wood.

Abstract

Hardwood trees produce tension wood (TW) with specific mechanical properties to cope with environmental cues. Poplar TW fibers have an additional cell wall layer, the G-layer responsible for TW mechanical properties. We investigated, in two poplar hybrid species, the molecules potentially involved in the building of TW mechanical properties. First, we evaluated the distribution of the different classes of non-cellulosic polysaccharides during xylem fiber differentiation, using immunolocalization. In parallel, G-layers were isolated and their polysaccharide composition determined. These complementary approaches provided information on the occurrence of non-cellulosic polysaccharides during G-fiber differentiation. We found no evidence of the presence of xyloglucan (XG) in poplar G-layers, whereas arabinogalactan proteins (AGP) and rhamnogalacturonan type I pectins (RG-I) were abundant, with an apparent progressive loss of RG-I side chains during G-layer maturation. Similarly, the intensity of immunolabeling signals specific for glucomannans and glucuronoxylans varies during G-layer maturation. RG-I and AGP are best candidate matrix components to be responsible for TW mechanical properties.

Keywords

Cellulose aggregation, G-fiber maturation, Hemicellulose, Hydrogel formation, Mechanical strain, Pectin

Commentaires


TOP