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Effect of K+ and Ca2+ on the indole-3-acetic acid- and fusicoccin-induced growth and membrane potential in maize coleoptile cells.

Siemieniuk A, Karcz W - AoB Plants (2015)

Bottom Line: It was also found that in parenchymal cells of maize coleoptile segments, membrane potential (Em) was strongly affected by the medium K(+), independently of Ca(2+).However, lack of Ca(2+) in the incubation medium significantly reduced the IAA- and FC-induced membrane potential hyperpolarization.Verapamil did not change either the Em of parenchymal cells incubated in the control medium or the IAA- and FC-induced membrane hyperpolarization.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28, 40-032 Katowice, Silesia, Poland.

No MeSH data available.


Related in: MedlinePlus

Effect of K+ and Ca2+ channel blockers (TEA-Cl and verapamil, respectively) on the IAA- and FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium with 1 mM K+ and 0.1 mM Ca2+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 60 min; afterwards the channel blockers were added. A total of 110 min after the start of preincubation, a single segment was transferred into an electrophysiological chamber containing the same medium (with channel blockers). Measurements of membrane potential (30 min) were carried out after insertion of a microelectrode into the cell (one cell per one segment) and stabilization of the Em (<10 min) at 2 h (0 min). Indole-3-acetic acid or FC, at a final concentration of 10 and 1 µM, respectively, were added after 2 h of segment preincubation in the indicated medium; for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber. Representative curves are shown. These curves were fitted with least-squares linear regression and subsequently smoothed using Statistica software for Windows (Version 8.0).
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PLV070F8: Effect of K+ and Ca2+ channel blockers (TEA-Cl and verapamil, respectively) on the IAA- and FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium with 1 mM K+ and 0.1 mM Ca2+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 60 min; afterwards the channel blockers were added. A total of 110 min after the start of preincubation, a single segment was transferred into an electrophysiological chamber containing the same medium (with channel blockers). Measurements of membrane potential (30 min) were carried out after insertion of a microelectrode into the cell (one cell per one segment) and stabilization of the Em (<10 min) at 2 h (0 min). Indole-3-acetic acid or FC, at a final concentration of 10 and 1 µM, respectively, were added after 2 h of segment preincubation in the indicated medium; for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber. Representative curves are shown. These curves were fitted with least-squares linear regression and subsequently smoothed using Statistica software for Windows (Version 8.0).

Mentions: Figure 8 and Table 2 show the effects of TEA-Cl and verapamil on either IAA- or FC-induced Em changes in parenchymal cells of maize coleoptile segments incubated in medium with 1 mM K+ and 0.1 mM Ca2+. Indole-3-acetic acid, added at 2 h of segment incubation in medium with 1 mM K+ and 0.1 mM Ca2+ (for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber), caused transient depolarization of the Em followed by a delayed membrane hyperpolarization during which membrane potential became by 9.2 mV more negative than the original potential (−121.0 ± 7.2 mV, mean ± SE, n = 13) (Fig. 8, Table 2). When TEA-Cl, at a final concentration of 30 mM, was added to the medium with 1 mM K+ and 0.1 mM Ca2+, after 1 h of segment incubation (for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber), the Em of cells was hyperpolarized by 16.3 mV. In turn, addition of IAA at this hyperpolarized state of membrane caused additional hyperpolarization of the Em by 25.4 mV at 30 min. Verapamil, added to medium in the same way as TEA-Cl, did not affect the original Em (Fig. 8, Table 2). Administration of IAA in the presence of verapamil induced hyperpolarization by 4.3 mV higher than for auxin alone. Similar dependences were recorded in the presence of FC and both channel blockers (Fig. 8, Table 2). All substances used with FC were added to the incubation medium in the same time protocol as was IAA. Addition of FC produced immediate hyperpolarization of Em, where the Em was by 19.7 mV more negative than the original value (−121.6 ± 6.1 mV, mean ± SE, n = 9). At 30 mM TEA-Cl, FC-induced membrane hyperpolarization was by 30.3 mV more negative than the Em value after 1 h of segment incubation in medium with TEA-Cl. Verapamil did not basically change the original Em (Table 2, column A). Fusicoccin, added at 2 h to the incubation medium with verapamil, after 30 min, caused a 20.4 mV hyperpolarization (from −119.0 ± 4.5 to −139.4 ± 6.1 mV, Table 2).Table 2.


Effect of K+ and Ca2+ on the indole-3-acetic acid- and fusicoccin-induced growth and membrane potential in maize coleoptile cells.

Siemieniuk A, Karcz W - AoB Plants (2015)

Effect of K+ and Ca2+ channel blockers (TEA-Cl and verapamil, respectively) on the IAA- and FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium with 1 mM K+ and 0.1 mM Ca2+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 60 min; afterwards the channel blockers were added. A total of 110 min after the start of preincubation, a single segment was transferred into an electrophysiological chamber containing the same medium (with channel blockers). Measurements of membrane potential (30 min) were carried out after insertion of a microelectrode into the cell (one cell per one segment) and stabilization of the Em (<10 min) at 2 h (0 min). Indole-3-acetic acid or FC, at a final concentration of 10 and 1 µM, respectively, were added after 2 h of segment preincubation in the indicated medium; for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber. Representative curves are shown. These curves were fitted with least-squares linear regression and subsequently smoothed using Statistica software for Windows (Version 8.0).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543891&req=5

PLV070F8: Effect of K+ and Ca2+ channel blockers (TEA-Cl and verapamil, respectively) on the IAA- and FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium with 1 mM K+ and 0.1 mM Ca2+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 60 min; afterwards the channel blockers were added. A total of 110 min after the start of preincubation, a single segment was transferred into an electrophysiological chamber containing the same medium (with channel blockers). Measurements of membrane potential (30 min) were carried out after insertion of a microelectrode into the cell (one cell per one segment) and stabilization of the Em (<10 min) at 2 h (0 min). Indole-3-acetic acid or FC, at a final concentration of 10 and 1 µM, respectively, were added after 2 h of segment preincubation in the indicated medium; for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber. Representative curves are shown. These curves were fitted with least-squares linear regression and subsequently smoothed using Statistica software for Windows (Version 8.0).
Mentions: Figure 8 and Table 2 show the effects of TEA-Cl and verapamil on either IAA- or FC-induced Em changes in parenchymal cells of maize coleoptile segments incubated in medium with 1 mM K+ and 0.1 mM Ca2+. Indole-3-acetic acid, added at 2 h of segment incubation in medium with 1 mM K+ and 0.1 mM Ca2+ (for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber), caused transient depolarization of the Em followed by a delayed membrane hyperpolarization during which membrane potential became by 9.2 mV more negative than the original potential (−121.0 ± 7.2 mV, mean ± SE, n = 13) (Fig. 8, Table 2). When TEA-Cl, at a final concentration of 30 mM, was added to the medium with 1 mM K+ and 0.1 mM Ca2+, after 1 h of segment incubation (for the last 10 min, coleoptile segments were incubated in the electrophysiological chamber), the Em of cells was hyperpolarized by 16.3 mV. In turn, addition of IAA at this hyperpolarized state of membrane caused additional hyperpolarization of the Em by 25.4 mV at 30 min. Verapamil, added to medium in the same way as TEA-Cl, did not affect the original Em (Fig. 8, Table 2). Administration of IAA in the presence of verapamil induced hyperpolarization by 4.3 mV higher than for auxin alone. Similar dependences were recorded in the presence of FC and both channel blockers (Fig. 8, Table 2). All substances used with FC were added to the incubation medium in the same time protocol as was IAA. Addition of FC produced immediate hyperpolarization of Em, where the Em was by 19.7 mV more negative than the original value (−121.6 ± 6.1 mV, mean ± SE, n = 9). At 30 mM TEA-Cl, FC-induced membrane hyperpolarization was by 30.3 mV more negative than the Em value after 1 h of segment incubation in medium with TEA-Cl. Verapamil did not basically change the original Em (Table 2, column A). Fusicoccin, added at 2 h to the incubation medium with verapamil, after 30 min, caused a 20.4 mV hyperpolarization (from −119.0 ± 4.5 to −139.4 ± 6.1 mV, Table 2).Table 2.

Bottom Line: It was also found that in parenchymal cells of maize coleoptile segments, membrane potential (Em) was strongly affected by the medium K(+), independently of Ca(2+).However, lack of Ca(2+) in the incubation medium significantly reduced the IAA- and FC-induced membrane potential hyperpolarization.Verapamil did not change either the Em of parenchymal cells incubated in the control medium or the IAA- and FC-induced membrane hyperpolarization.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28, 40-032 Katowice, Silesia, Poland.

No MeSH data available.


Related in: MedlinePlus