title: Helicoidal pattern in secondary cell walls and possible role of xylans in their construction.
abstract: The helicoidal organization of secondary cell walls is overviewed from several examples. Both the plywood texture and the occurrence of characteristic defects strongly suggest that the wall ordering is relevant of a cholesteric liquid-crystal assembly that is rapidly and strongly consolidated by lignification. A preferential localization of glucuronoxylans, major matrix components, and in vitro re-association experiments emphasize their preeminent role: (1) during the construction of the composite as directing the cellulose microfibrils in a helicoidal array; (2) during the lignification of the composite as a host structure for lignin precursors.
authors.affiliation: Laboratoire de pathologie végétale, UMR 217, INA P-G , 16, rue Claude-Bernard, 75231 Paris cedex 05, France. reis@inapg.inra.fr
authors.forename: Danièle
authors.initials: D
authors.lastname: Reis
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vian
mesh_terms: D002473:Cell Wall / Q000502:physiology* / Q000648:ultrastructure*; D018514:Plant Structures / Q000502:physiology* / Q000648:ultrastructure*; D014990:Xylans
chemical_list: D014990:Xylans