The wood cell wall at the ultrastructural scale - formation and topochemical organization
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| Format: | Artículo científico |
| Langue: | en |
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Universidad del Bío Bío
2006
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| _version_ | 1876478099617480704 |
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| author | Katia Ruel |
| author_facet | Katia Ruel |
| contents | The wood cell wall at the ultrastructural scale - formation and topochemical organization Katia Ruel Valérie Chevalier-billosta Florence Guillemin Jimmy Berrio Sierra Jean-Paul Joseleau Agrociencias Xylan Lignin Assembly Immunolabelling Secondary plant cell wall The macromolecular organization of the secondary wall of the cells from tree xylem is in large partresponsible for the mechanical and physiological properties of wood. Modeling secondary walls ofwood is difficult because information about their macromolecular architecture at the ultrastructuralscale is missing. Numerous microscopic studies have provided views of the lignocellulosic compositematerial, but nanoscale distribution of the polymers and their interaction in muro is still not clearlyunderstood. The intimate macromolecular organization of cell walls is defined during their differentiation.It is at the stage of wall thickening corresponding to secondary wall development that the topochemicalorganization and the interactions between cellulose, hemicelluloses and lignin are established.Using the conjunction of the high resolution of transmission electron microscopy (TEM) and thespecificity of immunological probes directed against the main cell wall polymers, we investigated thedeposition of hemicelluloses and lignins from the early stage of cambium differentiation to the maturefiber and vessel walls in growing model plants of Arabidopsis thaliana and poplar. TEM examination ofdifferentiating cells as well as various wood and wood derived materials and genetic plant mutantsbrought multiple evidence of the lamellar sub-organization of the secondary walls. Immuno-gold labelingshowed that two structurally different xylan types were deposited at different stages in the wall thickening.Similarly two different types of lignin molecules were shown to be differentially polymerized at differentsteps of the building of the wall, lignin molecules of the condensed type being first deposited at theearliest stage of secondary thickening before the non-condensed types. This process may be modifiedin response to environmental factors, as in tension wood.The spatio-temporal relationships occurring between hemicelluloses, lignin and cellulose microfibrils(CMFs) during the secondary wall development suggest that xylans with less substituted chains wouldbe more directly interacting with CMFs than those with higher substitution patterns. It also suggests thatlignin molecules of the non-condensed type have a function in bringing cohesion between the lamellaeof CMFs. A model of wall assembly during secondary thickening is proposed. 2006 artículo científico 0717-3644 https://www.redalyc.org/articulo.oa?id=48580204 en http://www.redalyc.org/revista.oa?id=485 Maderas. Ciencia y Tecnología application/pdf Universidad del Bío Bío Maderas. Ciencia y Tecnología (Chile) Num.2 Vol.8 |
| format | Artículo científico |
| id | redalyc_48580204 |
| institution | Redalyc |
| language | en |
| publishDate | 2006 |
| publisher | Universidad del Bío Bío |
| spellingShingle | The wood cell wall at the ultrastructural scale - formation and topochemical organization Katia Ruel Agrociencias Xylan Lignin Assembly Immunolabelling Secondary plant cell wall The wood cell wall at the ultrastructural scale - formation and topochemical organization Katia Ruel Valérie Chevalier-billosta Florence Guillemin Jimmy Berrio Sierra Jean-Paul Joseleau Agrociencias Xylan Lignin Assembly Immunolabelling Secondary plant cell wall The macromolecular organization of the secondary wall of the cells from tree xylem is in large partresponsible for the mechanical and physiological properties of wood. Modeling secondary walls ofwood is difficult because information about their macromolecular architecture at the ultrastructuralscale is missing. Numerous microscopic studies have provided views of the lignocellulosic compositematerial, but nanoscale distribution of the polymers and their interaction in muro is still not clearlyunderstood. The intimate macromolecular organization of cell walls is defined during their differentiation.It is at the stage of wall thickening corresponding to secondary wall development that the topochemicalorganization and the interactions between cellulose, hemicelluloses and lignin are established.Using the conjunction of the high resolution of transmission electron microscopy (TEM) and thespecificity of immunological probes directed against the main cell wall polymers, we investigated thedeposition of hemicelluloses and lignins from the early stage of cambium differentiation to the maturefiber and vessel walls in growing model plants of Arabidopsis thaliana and poplar. TEM examination ofdifferentiating cells as well as various wood and wood derived materials and genetic plant mutantsbrought multiple evidence of the lamellar sub-organization of the secondary walls. Immuno-gold labelingshowed that two structurally different xylan types were deposited at different stages in the wall thickening.Similarly two different types of lignin molecules were shown to be differentially polymerized at differentsteps of the building of the wall, lignin molecules of the condensed type being first deposited at theearliest stage of secondary thickening before the non-condensed types. This process may be modifiedin response to environmental factors, as in tension wood.The spatio-temporal relationships occurring between hemicelluloses, lignin and cellulose microfibrils(CMFs) during the secondary wall development suggest that xylans with less substituted chains wouldbe more directly interacting with CMFs than those with higher substitution patterns. It also suggests thatlignin molecules of the non-condensed type have a function in bringing cohesion between the lamellaeof CMFs. A model of wall assembly during secondary thickening is proposed. 2006 artículo científico 0717-3644 https://www.redalyc.org/articulo.oa?id=48580204 en http://www.redalyc.org/revista.oa?id=485 Maderas. Ciencia y Tecnología application/pdf Universidad del Bío Bío Maderas. Ciencia y Tecnología (Chile) Num.2 Vol.8 |
| title | The wood cell wall at the ultrastructural scale - formation and topochemical organization |
| topic | Agrociencias Xylan Lignin Assembly Immunolabelling Secondary plant cell wall |
| url | https://www.redalyc.org/articulo.oa?id=48580204 |