title: Localization of dibenzodioxocin substructures in lignifying Norway spruce xylem by transmission electron microscopy-immunogold labeling.
abstract: The lignification process in mature Norway spruce [ Picea abies (L.) H. Karsten] xylem cell walls was studied using transmission electron microscopy (TEM)-immunogold detection with a polyclonal antibody raised against a specific lignin substructure, dibenzodioxocin. The study reveals for the first time the exact location of this abundant eight-ring structure in the cell wall layers of wood. Spruce wood samples were collected in Southern Finland at the time of active growth and lignification of the xylem cell walls. In very young tracheids where secondary cell wall layers were not yet formed, the presence of the dibenzodioxocin structure could not be shown at all. During secondary cell wall thickening, the dibenzodioxocin structure was more abundant in the secondary cell wall layers than in the middle lamella. The highest number of gold particles revealing dibenzodioxocin was in the S2+S3 layer. Statistically significant differences were found in the frequency of gold particles present in various cell wall layers. For comparison, wood sections were also cut with a cryomicrotome for light and fluorescence microscopy.
authors.affiliation: Department of Biosciences, Division of Plant Physiology, Helsinki University, PO Box 56, 00014, Helsinki, Finland.
authors.forename: Eija M
authors.initials: EM
authors.lastname: Kukkola
authors.forename: Sanna
authors.initials: S
authors.lastname: Koutaniemi
authors.forename: Mikaela
authors.initials: M
authors.lastname: Gustafsson
authors.forename: Pirkko
authors.initials: P
authors.lastname: Karhunen
authors.forename: Katia
authors.initials: K
authors.lastname: Ruel
authors.forename: Taina K
authors.initials: TK
authors.lastname: Lundell
authors.forename: Pekka
authors.initials: P
authors.lastname: Saranpää
authors.forename: Gösta
authors.initials: G
authors.lastname: Brunow
authors.forename: Teemu H
authors.initials: TH
authors.lastname: Teeri
authors.forename: Kurt V
authors.initials: KV
authors.lastname: Fagerstedt
mesh_terms: D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure*; D006571:Heterocyclic Compounds / Q000378:metabolism*; D007150:Immunohistochemistry; D008031:Lignin / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D028222:Picea / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D018547:Plant Stems / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D014934:Wood
chemical_list: D006571:Heterocyclic Compounds; D008031:Lignin