Calcium-regulated anion channels in the plasma membrane of Lilium longiflorum pollen protoplasts
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.
| Publié dans: | The New phytologist. - 1979. - 192(2011), 1 vom: 01. Okt., Seite 45-60 |
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| Auteur principal: | |
| Autres auteurs: | , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2011
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Anions Chlorides Ion Channels Nitrates Nitrobenzoates Water 059QF0KO0R 5-nitro-2-(3-phenylpropylamino)benzoic acid plus... |
| Résumé: | © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust. • Currents through anion channels in the plasma membrane of Lilium longiflorum pollen grain protoplasts were studied under conditions of symmetrical anionic concentrations by means of patch-clamp whole-cell configuration. • With Cl(-) -based intra- and extracellular solutions, three outward-rectifying anion conductances, I(Cl1) , I(Cl2) and I(Cl3) , were identified. These three activities were discriminated by differential rundown behaviour and sensitivity to 5-nitro-2-(phenylpropylamino)-benzoate (NPPB), which could not be attributed to one or more channel types. All shared strong outward rectification, activated instantaneously and displayed a slow time-dependent activation for positive potentials. All showed modulation by intracellular calcium ([Ca(2+) ](in) ), increasing intensity from 6.04 nM up to 0.5 mM (I(Cl1) ), or reaching a maximum value with 8.50 μM (I(Cl2) and I(Cl3) ). • After rundown, the anionic currents measured using NO(3) (-) -based solutions were indistinguishable, indicating that the permeabilities of the channels for Cl(-) and NO(3) (-) are similar. Additionally, unitary anionic currents were measured from outside-out excised patches, confirming the presence of individual anionic channels. • This study shows for the first time the presence of a large anionic conductance across the membrane of pollen protoplasts, resulting from the presence of Ca(2+) -regulated channels. A similar conductance was also found in germinated pollen. We hypothesize that these putative channels may be responsible for the large anionic fluxes previously detected by means of self-referencing vibrating probes |
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| Description: | Date Completed 30.12.2011 Date Revised 23.04.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/j.1469-8137.2011.03780.x |