- Title
- Plasma membrane Ca²⁺-permeable channels are differentially regulated by ethylene and hydrogen peroxide to generate persistent plumes of elevated cytosolic Ca²⁺ during transfer cell trans-differentiation
- Creator
- Zhang, Hui-ming; van Helden, Dirk F.; McCurdy, David W.; Offler, Christina E.; Patrick, John W.
- Relation
- ARC.DP06646426 http://purl.org/au-research/grants/arc/DP0664626
- Relation
- Plant and Cell Physiology Vol. 56, Issue 9, p. 1711-1720
- Publisher Link
- http://dx.doi.org/10.1093/pcp/pcv100
- Publisher
- Oxford University Press
- Resource Type
- journal article
- Date
- 2015
- Description
- The enhanced transport capability of transfer cells (TCs) arises from their ingrowth wall architecture comprised of a uniform wall on which wall ingrowths are deposited. The wall ingrowth papillae provide scaffolds to amplify plasma membranes that are enriched in nutrient transporters. Using Vicia faba cotyledons, whose adaxial epidermal cells spontaneously and rapidly (hours) undergo a synchronous TC trans-differentiation upon transfer to culture, has led to the discovery of a cascade of inductive signals orchestrating deposition of ingrowth wall papillae. Auxin-induced ethylene biosynthesis initiates the cascade. This in turn drives a burst in extracellular H₂O₂ production that triggers uniform wall deposition. Thereafter, a persistent and elevated cytosolic Ca²⁺ concentration, resulting from Ca²⁺ influx through plasma membrane Ca²⁺-permeable channels, generates a Ca²⁺ signal that directs formation of wall ingrowth papillae to specific loci. We now report how these Ca²⁺-permeable channels are regulated using the proportionate responses in cytosolic Ca²⁺ concentration as a proxy measure of their transport activity. Culturing cotyledons on various combinations of pharmacological agents allowed the regulatory influence of each upstream signal on Ca²⁺ channel activity to be evaluated. The findings demonstrated that Ca²⁺-permeable channel activity was insensitive to auxin, but up-regulated by ethylene through two independent routes. In one route ethylene acts directly on Ca²⁺-permeable channel activity at the transcriptional and post-translational levels, through an ethylene receptor-dependent pathway. The other route is mediated by an ethylene-induced production of extracellular H₂O₂ which then acts translationally and post-translationally to up-regulate Ca²⁺-permeable channel activity. A model describing the differential regulation of Ca²⁺-permeable channel activity is presented.
- Subject
- Ca²⁺-permeable channels; cytosolic Ca²⁺ concentration; ethylene; ROS; transfer cell; <i>Vicia faba</i>
- Identifier
- http://hdl.handle.net/1959.13/1332614
- Identifier
- uon:26905
- Identifier
- ISSN:0032-0781
- Language
- eng
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