Force and compliance: rethinking morphogenesis in walled cells.
In the turgid cells of plants, protists, fungi, and bacteria, walls resist swelling; they also confer shape on the cell. These two functions are not unrelated: cell physiologists have generally agreed that morphogenesis turns on the deformation of existing wall and the deposition of new wall, while turgor pressure produces the work of expansion. In 1990, I summed up consensus in a phrase: "localized compliance with the global force of turgor pressure." My purpose here is to survey the impact of recent discoveries on the traditional conceptual framework. Topics include the recognition of a cytoskeleton in bacteria; the tide of information and insight about budding in yeast; the role of the Spitzenkörper in hyphal extension; calcium ions and actin dynamics in shaping a tip; and the interplay of protons, expansins and cellulose fibrils in cells of higher plants.
Harold
Franklin M
FM
Department of Microbiology, University of Washington, Seattle, WA 98195, USA. frankharold@earthlink.net
D001419:Bacteria / Q000166:cytology / Q000254:growth & development*; D055592:Biophysical Phenomena; D001703:Biophysics; D002473:Cell Wall / Q000502:physiology*; D005658:Fungi / Q000166:cytology / Q000254:growth & development*; D009024:Morphogenesis; D059828:Plant Cells; D063245:Plant Development