Structure of cellulose microfibrils in primary cell walls from Collenchyma

0388154 - ÚMCH 2013 RIV US eng J - Journal Article
Thomas, L. H. - Forsyth, V. T. - Šturcová, Adriana - Kennedy, C. J. - May, R. P. - Altaner, C. M. - Apperley, D. C. - Wess, T. J. - Jarvis, M. C.
Structure of cellulose microfibrils in primary cell walls from Collenchyma.
Plant Physiology. Roč. 161, č. 1 (2013), s. 465-476. ISSN 0032-0889. E-ISSN 1532-2548
R&D Projects: GA ČR GAP108/12/0703
Institutional support: RVO:61389013
Keywords : primary cell wall * cellulose microfibril structure * chain packing disorder
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 7.394, year: 2013

In the primary walls of growing plant cells, the glucose polymer cellulose is assembled into long microfibrils a few nanometers in diameter. The rigidity and orientation of these microfibrils control cell expansion; therefore, cellulose synthesis is a key factor in the growth and morphogenesis of plants. Celery (Apium graveolens) collenchyma is a useful model system for the study of primary wall microfibril structure because its microfibrils are oriented with unusual uniformity, facilitating spectroscopic and diffraction experiments. Using a combination of x-ray and neutron scattering methods with vibrational and nuclear magnetic resonance spectroscopy, we show that celery collenchyma microfibrils were 2.9 to 3.0 nm in mean diameter, with a most probable structure containing 24 chains in cross section, arranged in eight hydrogen-bonded sheets of three chains, with extensive disorder in lateral packing, conformation, and hydrogen bonding. A similar 18-chain structure, and 24-chain structures of different shape, fitted the data less well. Conformational disorder was largely restricted to the surface chains, but disorder in chain packing was not. That is, in position and orientation, the surface chains conformed to the disordered lattice constituting the core of each microfibril. There was evidence that adjacent microfibrils were noncovalently aggregated together over part of their length, suggesting that the need to disrupt these aggregates might be a constraining factor in growth and in the hydrolysis of cellulose for biofuel production.
Permanent Link: http://hdl.handle.net/11104/0217853