Micro-rheological behaviour and nonlinear rheology of networks assembled from polysaccharides from the plant cell wall

作者：Vincent R R R; Mansel B W; Kramer A; Kroy K; Williams M A K^*

来源：New Journal of Physics, 2013, 15(3): 035002.

DOI：10.1088/1367-2630/15/3/035002

The same fundamental questions that have driven enquiry into cytoskeletal mechanics can be asked of the considerably less-studied, yet arguably just as important, biopolymer matrix in the plant cell wall. In this case, it is well-known that polysaccharides, rather than filamentous and tubular protein assemblies, play a major role in satisfying the mechanical requirements of a successful cell wall, but developing a clear structure-function understanding has been exacerbated by the familiar issue of biological complexity. Herein, in the spirit of the mesoscopic approaches that have proved so illuminating in the study of cytoskeletal networks, the linear microrheological and strain-stiffening responses of biopolymeric networks reconstituted from pectin, a crucial cell wall polysaccharide, are examined. These are found to be well-captured by the glassy worm-like chain (GWLC) model of self-assembled semi-flexible filaments. Strikingly, the nonlinear mechanical response of these pectin networks is found to be much more sensitive to temperature changes than their linear response, a property that is also observed in F-actin networks, and is well reproduced by the GWLC model. Additionally, microrheological measurements suggest that over long timescales (%26gt;10 s) internal stresses continue to redistribute facilitating low frequency motions of tracer particles.

• 出版日期2013-3-1