Pavement cells
Pavement cells are a cell type found in the outmost epidermal layer of plants. The main purpose of these cells is to form a protective layer for the more specialized cells below.[1] This layer helps decrease water loss, maintain an internal temperature, keep the inner cells in place, and resist the intrusion of any outside material.[2] They also separate stomata apart from each other as stomata have at least one pavement cell between each other.[3]
They do not have a regular shape. Rather, their irregular shapes help them to interlock with each other like puzzle pieces to form a sturdy layer.[4] This irregular shape that each individual cell takes on can be influenced by the cytoskeleton and specific proteins.[5] As the leaf grows, the pavement cells will also grow, divide, and synthesize new vacuoles, plasma membrane parts, and cell wall components. A thick external cell wall influences the direction of growth by impeding expansion towards the outside of the cell and instead promote expansion parallel to the epidermis layer.[6] Data suggest that waviness of pavement cells may be initiated by compressive mechanical stresses in a feedback loop that solidifies and augments cell shapes resulting in local reinforcement of the cell wall.[7]
References
- ^ Glover, B. J. (2000). "Differentiation in plant epidermal cells". Journal of Experimental Botany. 51 (344): 497–505. doi:10.1093/jexbot/51.344.497. PMID 10938806.
- ^ Qian, P.; Hou, S.; Guo, G. (2009). "Molecular mechanisms controlling pavement cell shape in Arabidopsis leaves". Plant Cell Reports. 28 (8): 1147–1157. doi:10.1007/s00299-009-0729-8.
- ^ Bird, S. M.; Gray, J. E. (2003). "Signals from the cuticle affect epidermal cell differentiation". New Phytologist. 157 (1): 9–27. doi:10.1046/j.1469-8137.2003.00543.x.
- ^ Glover, B. J. (2000). "Differentiation in plant epidermal cells". Journal of Experimental Botany. 51 (344): 497–505. doi:10.1093/jexbot/51.344.497. PMID 10938806.
- ^ Qian, P.; Hou, S.; Guo, G. (2009). "Molecular mechanisms controlling pavement cell shape in Arabidopsis leaves". Plant Cell Reports. 28 (8): 1147–1157. doi:10.1007/s00299-009-0729-8.
- ^ Zhang, C.; Halsey, L. E.; Szymanski, D. B. (2011). "The development and geometry of shape change in Arabidopsis thaliana cotyledon pavement cells". BMC Plant Biology. 11 (11): 27. doi:10.1186/1471-2229-11-27. PMC 3042916. PMID 21284861.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Bidhendi, Amir J.; Altartouri, Bara; Gosselin, Frédérick P.; Geitmann, Anja (July 2019). "Mechanical stress initiates and sustains the morphogenesis of wavy leaf epidermal cells". Cell Reports. 28 (5): 1237–1250. doi:10.1016/j.celrep.2019.07.006. PMID 31365867.