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Voltage-dependent calcium-permeable channels in the plasma membrane of a higher plant cell.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Thuleau, Patrice Ward, Jerrold M. Ranjeva, Raoul Schroeder, Julian I. |
| Copyright Year | 1994 |
| Abstract | Numerous biological assays and pharmacological studies on various higher plant tissues have led to the suggestion that voltage-dependent plasma membrane Ca2+ channels play prominent roles in initiating signal transduction processes during plant growth and development. However, to date no direct evidence has been obtained for the existence of such depolarization-activated Ca2+ channels in the plasma membrane of higher plant cells. Carrot suspension cells (Daucus carota L.) provide a well-suited system to determine whether voltage-dependent Ca2+ channels are present in the plasma membrane of higher plants and to characterize the properties of putative Ca2+ channels. It is known that both depolarization, caused by raising extracellular K+, and exposure to fungal toxins or oligogalacturonides induce Ca2+ influx into carrot cells. By direct application of patch-clamp techniques to isolated carrot protoplasts, we show here that depolarization of the plasma membrane positive to -135 mV activates Ca(2+)-permeable channels. These voltage-dependent ion channels were more permeable to Ca2+ than K+, while displaying large permeabilities to Ba2+ and Mg2+ ions. Ca(2+)-permeable channels showed slow and reversible inactivation. The single-channel conductance was 13 pS in 40 mM CaCl2. These data provide direct evidence for the existence of voltage-dependent Ca2+ channels in the plasma membrane of a higher plant cell and point to physiological mechanisms for plant Ca2+ channel regulation. The depolarization-activated Ca(2+)-permeable channels identified here could constitute a regulated pathway for Ca2+ influx in response to physiologically occurring stimulus-induced depolarizations in higher plant cells. |
| File Format | PDF HTM / HTML |
| DOI | 10.1002/j.1460-2075.1994.tb06595.x |
| PubMed reference number | 8039493 |
| Journal | Medline |
| Volume Number | 13 |
| Issue Number | 13 |
| Alternate Webpage(s) | http://www.esalq.usp.br/lepse/imgs/conteudo_thumb/Voltage-dependent-calcium-permeable-channels-in-the-plasma-membrane-of-a-higher-plant-cell.pdf |
| Alternate Webpage(s) | https://doi.org/10.1002/j.1460-2075.1994.tb06595.x |
| Journal | The EMBO journal |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
