Aim: Isolate and characterize lignin from outer cell wall
Background: The projects goal is to obtain information regarding the differences in
the lignin structure within the individual cell walls, i.e., the cell wall
layers in spruce and aspen. It has been suggested that such differences occur,
but the experimental evidence for this have so far been limited, to a large
extent due to the difficulties in obtaining sufficient amounts of material for
lignin analysis of separate cell wall layers. In this project we prepare plant
materials enriched in primary cell wall/middle lamella/S1 layers and analyze the
lignin structures with GC-MS, GPC and NMR. To verify that the material has an
increased proportion of outer cell wall material AFM and confocal microscopy are
employed. Carbohydrate monomer distribution is also determined since it is
diagnostic for different cell wall layers.
description: So far three different sources for plant materials
with an increased amount of outer cell layers as compared to woody tissue, which
contain mostly secondary cell, wall have been analyzed.
poplar cell suspension cultures, have been investigated.
three approximately 10 year old aspen trees were collected at the end of June
2003, frozen and de-barked while semi frozen. Thereafter the phloem rich region
inside the bark and the xylem rich side of the log were collected separately by
scraping the semi frozen tissue with scalpels. This area, the vascular region,
produces new cells for the tree and even though some of these cells contain
secondary cell walls the hypothesis was that in early summer
most of the cells that produce secondary cell walls would not have had
time to lignify the inner layers yet.
white spruce that have been preserved under anaerobic conditions for 10 000
years has been investigated. The sample has an intact outer cell wall and middle
lamella, but the secondary cell wall have been selectively removed by