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bioRxiv · 10.1101/492140

Cryo-Electron tomography 3D structure and nanoscale model of Arabidopsis thaliana cell wall

Sarkar, P.·Kowalczyk, M.·Apte, S.·Yap, E. G.·Das, J.·Adams, P. D.·Bajaj, C.·Guindos, P.·Auer, M.
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Abstract

Using cryo-electron tomography of vitrified sections of one month-old Arabidopsis thaliana inflorescence stem tissue, we visualized primary and secondary cell walls of xylem tissue. Extensive quantitative and statistical analysis of segmented 3D tomographic data allowed geometrically idealized 3D-CAD model building of prototypic microfibrils, cross-links, and their supramolecular microfibril 3D organization. We propose a prototypic microfibril model where a cellulose core is heavily decorated by a thin sheath of hemicellulose with infrequent but sturdy hemicellulose-based cross-links. Such prototypic microfibrils then adopt a rather unexpected 3D supramolecular organization of high order and complexity. We discuss a possible new role for lignin in plant cell walls at low concentrations with lignin not acting as a matrix but rather as a reinforcement of microfibrils and cross-links. Extensive computational simulations of mechanical properties further revealed that this 3D organization of the cell wall is not optimized for load bearing but instead for flexibility and ductility.\n\nOne Sentence SummaryCryo-electron tomography and mechanical simulations revealed cell wall 3D architecture, optimized for flexibility/ductility.

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Sarkar, P., Kowalczyk, M., Apte, S., Yap, E. G., Das, J., Adams, P. D., Bajaj, C., Guindos, P., Auer, M.. 2018-12-10. Cryo-Electron tomography 3D structure and nanoscale model of Arabidopsis thaliana cell wall. https://doi.org/10.1101/492140

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