Abstract

Although there is considerable information on the chemistry of bordered intervessel pit membranes, little is known on the pit membrane chemistry of other pit types in hardwoods. This study investigated distribution of phenolic compounds, pectins and hemicelluloses in different mature pit membranes of English oak xylem using transmission electron microscopy coupled with cytochemistry and immunocytochemistry. Mature bordered intertracheid (vasicentric)- and tracheid-vessel pits showed presence of xyloglucan and heteromannan (hemicelluloses) epitopes across the pit membrane (except for the annulus regions) with differences in amounts of epitopes between earlywood (EW) and latewood (LW). In contrast, pectin epitopes were detected only in the annulus regions of pit membranes. Unlike bordered pits, half-bordered (tracheary-parenchyma pits) and simple (parenchyma pits) pit membranes were rich in pectin epitopes but lacked heteromannan epitopes, indicating difference in pit membrane chemistry between pit types. Distribution of phenolic compounds also differed between pit types and between EW and LW. LW also showed great variations in distribution of phenolic compounds between vessels. Together, this study demonstrates that there are great variations in pit membrane chemistry between pit types and between EW and LW in English oak xylem..

Keywords

Bordered pit; half-bordered pit; immunocytochemistry; heteromannan; non-cellulosic polysaccharide; pit membrane chemistry; simple pit; xyloglucan.

Published in

IAWA Journal
2016, Volume: 37, number: 3, pages: 402-419

SLU Authors

• Kim, Jongsik

  • Department of Forest Products, Swedish University of Agricultural Sciences
    

• Daniel, Geoffrey

  • Department of Forest Products, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Wood Science


Publication identifier

DOI: https://doi.org/10.1163/22941932-20160143

Permanent link to this page (URI)

https://res.slu.se/id/publ/78196