Localization of dibenzodioxocin substructures in lignifying Norway spruce xylem by transmission electron microscopy-immunogold labeling.
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.
Kukkola
Eija M
EM
Department of Biosciences, Division of Plant Physiology, Helsinki University, PO Box 56, 00014, Helsinki, Finland.
Koutaniemi
Sanna
S
Gustafsson
Mikaela
M
Karhunen
Pirkko
P
Ruel
Katia
K
Lundell
Taina K
TK
Saranpää
Pekka
P
Brunow
Gösta
G
Teeri
Teemu H
TH
Fagerstedt
Kurt V
KV
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
D006571:Heterocyclic Compounds; D008031:Lignin