- Title
- Polarized and persistent Ca²⁺ plumes define loci for formation of wall ingrowth papillae in transfer cells
- Creator
- Zhang, Hui-Ming; Imtiaz, Mohammad S.; Laver, Derek R.; McCurdy, David W.; Offler, Christina E.; van Helden, Dirk F.; Patrick, John W.
- Relation
- ARC.DP0664626 & NHMRC.1005974 http://purl.org/au-research/grants/nhmrc/1005974
- Relation
- Journal of Experimental Botany Vol. 66, Issue 5, p. 1179-1190
- Publisher Link
- http://dx.doi.org/10.1093/jxb/eru460
- Publisher
- Oxford University Press
- Resource Type
- journal article
- Date
- 2015
- Description
- Transfer cell morphology is characterized by a polarized ingrowth wall comprising a uniform wall upon which wall ingrowth papillae develop at right angles into the cytoplasm. The hypothesis that positional information directing construction of wall ingrowth papillae is mediated by Ca²⁺ signals generated by spatiotemporal alterations in cytosolic Ca²⁺ ([Ca²⁺]cyt) of cells trans-differentiating to a transfer cell morphology was tested. This hypothesis was examined using Vicia faba cotyledons. On transferring cotyledons to culture, their adaxial epidermal cells synchronously trans-differentiate to epidermal transfer cells. A polarized and persistent Ca²⁺ signal, generated during epidermal cell trans-differentiation, was found to co-localize with the site of ingrowth wall formation. Dampening Ca²⁺ signal intensity, by withdrawing extracellular Ca²⁺ or blocking Ca²⁺ channel activity, inhibited formation of wall ingrowth papillae. Maintenance of Ca²⁺ signal polarity and persistence depended upon a rapid turnover (minutes) of cytosolic Ca²⁺ by co-operative functioning of plasma membrane Ca²⁺-permeable channels and Ca²⁺-ATPases. Viewed paradermally, and proximal to the cytosol-plasma membrane interface, the Ca²⁺ signal was organized into discrete patches that aligned spatially with clusters of Ca²⁺-permeable channels. Mathematical modelling demonstrated that these patches of cytosolic Ca²⁺ were consistent with inward-directed plumes of elevated [Ca²⁺]cyt. Plume formation depended upon an alternating distribution of Ca²⁺-permeable channels and Ca²⁺-ATPase clusters. On further inward diffusion, the Ca²⁺ plumes coalesced into a uniform Ca²⁺ signal. Blocking or dispersing the Ca²⁺ plumes inhibited deposition of wall ingrowth papillae, while uniform wall formation remained unaltered. A working model envisages that cytosolic Ca²⁺ plumes define the loci at which wall ingrowth papillae are deposited.
- Subject
- Ca²⁺ signal; localized cell wall deposition; seed; <i>trans</i>-differentiation; transfer cell; wall ingrowth
- Identifier
- http://hdl.handle.net/1959.13/1332646
- Identifier
- uon:26914
- Identifier
- ISSN:0022-0957
- Rights
- This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
- Language
- eng
- Full Text
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