Abstract
Microfibril deposition in most plant cells is influenced by cortical microtubules. Thus, cortical microtubules are templates that provide spatial information to the cell wall. How cortical microtubules acquire their spatial information and are positioned is unknown. There are indications that plant cells respond to mechanical stresses by using microtubules as sensing elements. Regenerating protoplasts from tobacco (Nicotiana tabacum) were used to determine whether cells can be induced to expand in a preferential direction in response to an externally applied unidirectional force. Additionally, an anti-microtubule herbicide was used to investigate the role of microtubules in the response to this force. Protoplasts were embedded in agarose, briefly centrifuged at 28 to 34g, and either cultured or immediately prepared for immunolocalization of their microtubules. The microtubules within many centrifuged protoplasts were found to be oriented parallel to the centrifugal force vector. Most protoplasts elongated with a preferential axis that was oriented 60 to 90 degrees to the applied force vector. Protoplasts treated transiently with the reversible microtubule-disrupting agent amiprophos-methyl (applied before and during centrifugation) elongated but without a preferential growth axis. These results indicate that brief biophysical forces may influence the alignment of cortical microtubules and that microtubules themselves act as biophysical responding elements.
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Selected References
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- Cyr R. J. Microtubules in plant morphogenesis: role of the cortical array. Annu Rev Cell Biol. 1994;10:153–180. doi: 10.1146/annurev.cb.10.110194.001101. [DOI] [PubMed] [Google Scholar]
- Cyr R. J., Palevitz B. A. Organization of cortical microtubules in plant cells. Curr Opin Cell Biol. 1995 Feb;7(1):65–71. doi: 10.1016/0955-0674(95)80046-8. [DOI] [PubMed] [Google Scholar]
- Grabski S., Xie X. G., Holland J. F., Schindler M. Lipids trigger changes in the elasticity of the cytoskeleton in plant cells: a cell optical displacement assay for live cell measurements. J Cell Biol. 1994 Aug;126(3):713–726. doi: 10.1083/jcb.126.3.713. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hahne G., Hoffmann F. The effect of laser microsurgery on cytoplasmic strands and cytoplasmic streaming in isolated plant protoplasts. Eur J Cell Biol. 1984 Mar;33(2):175–179. [PubMed] [Google Scholar]
- Hardham A. R., Gunning B. E. Structure of cortical microtubule arrays in plant cells. J Cell Biol. 1978 Apr;77(1):14–34. doi: 10.1083/jcb.77.1.14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hernandez L. F., Green P. B. Transductions for the Expression of Structural Pattern: Analysis in Sunflower. Plant Cell. 1993 Dec;5(12):1725–1738. doi: 10.1105/tpc.5.12.1725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ledbetter M. C., Porter K. R. Morphology of Microtubules of Plant Cell. Science. 1964 May 15;144(3620):872–874. doi: 10.1126/science.144.3620.872. [DOI] [PubMed] [Google Scholar]
- Morejohn L. C., Fosket D. E. Inhibition of Plant Microtubule Polymerization in vitro by the Phosphoric Amide Herbicide Amiprophos-Methyl. Science. 1984 May 25;224(4651):874–876. doi: 10.1126/science.224.4651.874. [DOI] [PubMed] [Google Scholar]
- Murthy J. V., Kim H. H., Hanesworth V. R., Hugdahl J. D., Morejohn L. C. Competitive Inhibition of High-Affinity Oryzalin Binding to Plant Tubulin by the Phosphoric Amide Herbicide Amiprophos-Methyl. Plant Physiol. 1994 May;105(1):309–320. doi: 10.1104/pp.105.1.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zandomeni K., Schopfer P. Mechanosensory microtubule reorientation in the epidermis of maize coleoptiles subjected to bending stress. Protoplasma. 1994;182(3-4):96–101. doi: 10.1007/BF01403471. [DOI] [PubMed] [Google Scholar]