Nanoscale movements of cellulose microfibrils in primary cell walls
- Pennsylvania State Univ., University Park, PA (United States). Center for Lignocellulose Structure and Formation (CLSF) and Dept. of Biology
- Lehigh Univ., Bethlehem, PA (United States). Dept. of Physics
The growing plant cell wall is commonly considered to be a fibre-reinforced structure whose strength, extensibility and anisotropy depend on the orientation of crystalline cellulose microfibrils, their bonding to the polysaccharide matrix and matrix viscoelasticity. Structural reinforcement of the wall by stiff cellulose microfibrils is central to contemporary models of plant growth, mechanics and meristem dynamics. Although passive microfibril reorientation during wall extension has been inferred from theory and from bulk measurements, nanometre-scale movements of individual microfibrils have not been directly observed. For this, we combined nanometre-scale imaging of wet cell walls by atomic force microscopy (AFM) with a stretching device and endoglucanase treatment that induces wall stress relaxation and creep, mimicking wall behaviours during cell growth. Microfibril movements during forced mechanical extensions differ from those during creep of the enzymatically loosened wall. In addition to passive angular reorientation, we observed a diverse repertoire of microfibril movements that reveal the spatial scale of molecular connections between microfibrils. Our results show that wall loosening alters microfibril connectivity, enabling microfibril dynamics not seen during mechanical stretch. These insights into microfibril movements and connectivities need to be incorporated into refined models of plant cell wall structure, growth and morphogenesis.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); National Institutes of Health (NIH)
- Grant/Contract Number:
- SC0001090; R01GM098430
- OSTI ID:
- 1463092
- Journal Information:
- Nature Plants (Online), Vol. 3, Issue 5; ISSN 2055-0278
- Publisher:
- Nature Publishing GroupCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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