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.

Automated summary

Scanning X-ray microdiffraction was used to study the structural variations of cellulose microfibrils among different cell types of beechwood. Diffraction patterns collected from cell walls revealed that fiber cells had a longitudinal cellulose signal, while ray and vessel cells showed transversal fiber alignment to a lesser degree. In addition, the scattering patterns at small angles were less pronounced in ray and vessel cells compared to fiber cells. These findings suggest that crystalline cellulose in fiber cells has a distinct structure at the meso and molecular level compared to ray and vessel cellulose in beechwood.