Probing the structural variations of different tissue cells in beechwood by X-ray microdiffraction

Scanning X-ray microdiffraction is applied to determine the structural variations of cellulose microfibrils among the fiber cells, vessel cells and ray cells of beechwood. A longitudinal section of beechwood was raster scanned with an X-ray microbeam. This allows to collect diffraction patterns from cell walls of distinct cell types. While the diffraction patterns from fiber cells are dominated by the cellulose signal with a longitudinal orientation, the diffraction patterns from ray and vessel cells show transversal fiber alignment, however to a lower degree of orientation. Moreover, the scattering pattern at small angle region of ray and vessel cells become less pronounced than to fiber cells. These results suggest that the crystalline cellulose of fiber cells has a completely different structure at the meso and molecular level when compared to ray and vessel cellulose within beechwood.