Ca2+ Effects on K+ Fluxes in Arabidopsis Seedlings Exposed to Al3+ |
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Authors: | Olga Babourina Konstantin Voltchanskii Ian Newman Zed Rengel |
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Affiliation: | University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia;University of Tasmania, GPO Box 252–21, Hobart TAS 7001, Australia |
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Abstract: | Potassium transport was investigated in the root elongation zone of Arabidopsis seedlings during the first minutes of Al3+ exposure, using the non-invasive MIFE microelectrode technique. To prevent pH changes during Al3+ application, and to separate aluminium from acidic stress, plants were pre-treated with 5 mM homoPIPES before addition of AlCl3 (pH 4.2). The 30-min treatment with 50 or 500 μM AlCl3 led to a significant increase in K+ efflux in solutions containing 100 μM CaCl2. This efflux was suppressed by high concentrations of Ca2+ (10 mM) in the bathing solution. Our results suggest that elevated external Ca2+ activities can sustain K+ influx in the root elongation zone during Al3+ exposure either by maintaining [Ca2+]cyt or by affecting Al3+ uptake across the plasma membrane. |
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Keywords: | acid stress Al3+ Arabidopsis Ca2+ K+ |
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