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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 different concentrations of Ca2+ ions on the FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium without K+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 110 min; afterwards a single segment was transferred into an electrophysiological chamber containing the same medium. 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). Fusicoccin, at a final concentration of 1 µM, was 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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PLV070F7: Effect of different concentrations of Ca2+ ions on the FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium without K+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 110 min; afterwards a single segment was transferred into an electrophysiological chamber containing the same medium. 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). Fusicoccin, at a final concentration of 1 µM, was 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: Results shown in Table 1 indicate that the membrane potential of parenchymal cells of maize coleoptile segments depended on K+ concentration, not on Ca2+ concentration (Table 1, column A). For example, a 10-fold increase in K+ concentration, independently of Ca2+ concentration, caused depolarization by ∼56 mV, which is near the value predicted from the Nernst equation. Addition of IAA to the incubation medium (Table 1, Fig. 6) caused transient depolarization of the Em, followed by a delayed hyperpolarization, during which membrane potential became more negative than the original potential. In the presence of IAA, membrane hyperpolarization was not statistically significant in media without Ca2+ (Table 1, Fig. 6). In contrast to IAA, FC caused an immediate hyperpolarization of the Em, attaining significantly higher values independently of K+ and Ca2+ concentrations. Similarly to IAA, the FC-induced membrane potential hyperpolarization was inhibited in the absence of Ca2+ (Table 1, Fig. 7) and showed a decrease with increasing K+ concentration.Table 1.


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 different concentrations of Ca2+ ions on the FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium without K+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 110 min; afterwards a single segment was transferred into an electrophysiological chamber containing the same medium. 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). Fusicoccin, at a final concentration of 1 µM, was 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

PLV070F7: Effect of different concentrations of Ca2+ ions on the FC-induced changes in the Em measured in maize coleoptile parenchymal cells in a medium without K+. Coleoptile segments were incubated in the indicated medium (the same as in growth experiments) for 110 min; afterwards a single segment was transferred into an electrophysiological chamber containing the same medium. 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). Fusicoccin, at a final concentration of 1 µM, was 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: Results shown in Table 1 indicate that the membrane potential of parenchymal cells of maize coleoptile segments depended on K+ concentration, not on Ca2+ concentration (Table 1, column A). For example, a 10-fold increase in K+ concentration, independently of Ca2+ concentration, caused depolarization by ∼56 mV, which is near the value predicted from the Nernst equation. Addition of IAA to the incubation medium (Table 1, Fig. 6) caused transient depolarization of the Em, followed by a delayed hyperpolarization, during which membrane potential became more negative than the original potential. In the presence of IAA, membrane hyperpolarization was not statistically significant in media without Ca2+ (Table 1, Fig. 6). In contrast to IAA, FC caused an immediate hyperpolarization of the Em, attaining significantly higher values independently of K+ and Ca2+ concentrations. Similarly to IAA, the FC-induced membrane potential hyperpolarization was inhibited in the absence of Ca2+ (Table 1, Fig. 7) and showed a decrease with increasing K+ concentration.Table 1.

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