Plant cell walls are composed of a framework of cellulose microfibrils that are
interconnected with heteropolysaccharides (lignin, hemicelluloses) in a specific
manner. Plant cell walls form a large part of the plant body and define its
characteristics. Structural organisation of the cell wall and related polymers is
important for both mechanical properties of plants and chemical reactions occurring
in the wall space, especially in the response to stress.By using imaging FTIR
microscopy, run in transmission mode and at different polarisation modes (from 0° to
90°), it is possible to follow the chemical variability and the orientation of cell wall
polymers (cellulose, hemicelluloses and lignin) of the Arabidopsis thaliana stem. The
polarised FTIR measurements indicated that both xylan and lignin have parallel
orientation with regard to the orientation of cellulose. It is believed that this structuring
of lignin in the S2 layer of the cell wall might be a result of the spatial constraints
within the cell wall, occuring due to the previous deposition of
cellulose/hemicellulose in a strongly oriented assembly