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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+ ions on the IAA-induced growth rate of maize coleoptile segments. (A) IAA-induced growth rate (µm s−1 cm−1) of coleoptile segments incubated in the medium with 0.0 mM K+ and Ca2+ at 0.0, 0.1 and 1.0 mM. (B) As in A but with 1.0 mM K+. (C) As in A and B but with 10 mM K+ in the medium. The growth rate of five coleoptile segments (10 mm in length) was recorded for 10 h in an intensively aerated incubation medium (5 mL segment−1) by means of an angular position transducer (TWK Electronic). Coleoptile segments were first preincubated for 2 h in a control medium, whereupon IAA was added at a final concentration of 10 µM. Inset shows total elongation growth, calculated as the sum of extensions measured in 3-min intervals for 10 h. All curves are mean values of at least eight independent measurements. Bars indicate ±SE.
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PLV070F2: Effect of K+ and Ca2+ ions on the IAA-induced growth rate of maize coleoptile segments. (A) IAA-induced growth rate (µm s−1 cm−1) of coleoptile segments incubated in the medium with 0.0 mM K+ and Ca2+ at 0.0, 0.1 and 1.0 mM. (B) As in A but with 1.0 mM K+. (C) As in A and B but with 10 mM K+ in the medium. The growth rate of five coleoptile segments (10 mm in length) was recorded for 10 h in an intensively aerated incubation medium (5 mL segment−1) by means of an angular position transducer (TWK Electronic). Coleoptile segments were first preincubated for 2 h in a control medium, whereupon IAA was added at a final concentration of 10 µM. Inset shows total elongation growth, calculated as the sum of extensions measured in 3-min intervals for 10 h. All curves are mean values of at least eight independent measurements. Bars indicate ±SE.

Mentions: When IAA, at a final concentration of 10 µM, was added to the control medium, 2 h after the start of the experiment, a strong increase was observed in the growth rate (Fig. 2). The kinetics of IAA-induced growth could be divided into two phases (biphasic reaction) as previously described (Vanderhoef and Stahl 1975; Kazama and Katsumi 1976; Vanderhoef and Dute 1981; Philippar et al. 1999; Polak 2010); the first phase, very rapid, was followed by a long-lasting one, which began ∼30 min after auxin addition. In the absence of K+ in the incubation medium (Fig. 2A), Ca2+ at 0.1 and 1 mM significantly (F2,22 = 4.83, P = 0.018) diminished IAA-induced elongation growth by 31 %, as compared with IAA-induced growth in medium without Ca2+ and K+ (3357.8 ± 372.5 µm cm−1; mean ± SE, n = 9, Fig. 2A, inset). However, in the presence of 1 mM K+, IAA-induced elongation growth of coleoptile segments was significantly reduced (by 26 %) at 1 mM Ca2+ (F2,25 = 3.757, P = 0.037). When IAA was added to the medium containing 10 mM K+, auxin-induced growth did not depend on Ca2+ concentration (F2,21 = 0.031, P = 0.97) (Fig. 2C). Effects of K+ and Ca2+ were also studied for the growth of maize coleoptile segments incubated in the presence of FC (Fig. 3). This fungal toxin is known to enhance H+-ATPase activity, through phosphorylation of the penultimate Thr, as well as induce elongation growth (Marrè 1979; Kinoshita and Shimazaki 2001). Fusicoccin added to the incubation medium in the same way as IAA, at a final concentration of 1 µM, enhanced the endogenous growth of maize coleoptile segments to a level comparable with growth seen in the presence of IAA (Fig. 2). Independently of the ionic composition of the medium, FC added at 2 h of segment preincubation caused rapid growth with bell-shaped kinetics (Fig. 3). In the absence of K+ in incubation medium (Fig. 3A), Ca2+ at 0.1 and 1 mM significantly inhibited FC-induced elongation growth (F2,23 = 12.79, P < 0.01) by 46 % compared with growth in medium without Ca2+ and K+ (3378.3 ± 338.6 µm cm−1; mean ± SE, n = 8, Fig. 3A, inset). In medium with 1 mM K+ and Ca2,+ at both concentrations, inhibition of FC-induced growth was significant (F2,25 = 4.07, P = 0.029) but did not exceed 25 % (Fig. 3B). As in the case of IAA, FC-induced growth in a medium containing 10 mM K+ did not depend on Ca2+ concentration (F2,24 = 0.215, P = 0.807) (Fig. 3C).Figure 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+ ions on the IAA-induced growth rate of maize coleoptile segments. (A) IAA-induced growth rate (µm s−1 cm−1) of coleoptile segments incubated in the medium with 0.0 mM K+ and Ca2+ at 0.0, 0.1 and 1.0 mM. (B) As in A but with 1.0 mM K+. (C) As in A and B but with 10 mM K+ in the medium. The growth rate of five coleoptile segments (10 mm in length) was recorded for 10 h in an intensively aerated incubation medium (5 mL segment−1) by means of an angular position transducer (TWK Electronic). Coleoptile segments were first preincubated for 2 h in a control medium, whereupon IAA was added at a final concentration of 10 µM. Inset shows total elongation growth, calculated as the sum of extensions measured in 3-min intervals for 10 h. All curves are mean values of at least eight independent measurements. Bars indicate ±SE.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Show All Figures
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PLV070F2: Effect of K+ and Ca2+ ions on the IAA-induced growth rate of maize coleoptile segments. (A) IAA-induced growth rate (µm s−1 cm−1) of coleoptile segments incubated in the medium with 0.0 mM K+ and Ca2+ at 0.0, 0.1 and 1.0 mM. (B) As in A but with 1.0 mM K+. (C) As in A and B but with 10 mM K+ in the medium. The growth rate of five coleoptile segments (10 mm in length) was recorded for 10 h in an intensively aerated incubation medium (5 mL segment−1) by means of an angular position transducer (TWK Electronic). Coleoptile segments were first preincubated for 2 h in a control medium, whereupon IAA was added at a final concentration of 10 µM. Inset shows total elongation growth, calculated as the sum of extensions measured in 3-min intervals for 10 h. All curves are mean values of at least eight independent measurements. Bars indicate ±SE.
Mentions: When IAA, at a final concentration of 10 µM, was added to the control medium, 2 h after the start of the experiment, a strong increase was observed in the growth rate (Fig. 2). The kinetics of IAA-induced growth could be divided into two phases (biphasic reaction) as previously described (Vanderhoef and Stahl 1975; Kazama and Katsumi 1976; Vanderhoef and Dute 1981; Philippar et al. 1999; Polak 2010); the first phase, very rapid, was followed by a long-lasting one, which began ∼30 min after auxin addition. In the absence of K+ in the incubation medium (Fig. 2A), Ca2+ at 0.1 and 1 mM significantly (F2,22 = 4.83, P = 0.018) diminished IAA-induced elongation growth by 31 %, as compared with IAA-induced growth in medium without Ca2+ and K+ (3357.8 ± 372.5 µm cm−1; mean ± SE, n = 9, Fig. 2A, inset). However, in the presence of 1 mM K+, IAA-induced elongation growth of coleoptile segments was significantly reduced (by 26 %) at 1 mM Ca2+ (F2,25 = 3.757, P = 0.037). When IAA was added to the medium containing 10 mM K+, auxin-induced growth did not depend on Ca2+ concentration (F2,21 = 0.031, P = 0.97) (Fig. 2C). Effects of K+ and Ca2+ were also studied for the growth of maize coleoptile segments incubated in the presence of FC (Fig. 3). This fungal toxin is known to enhance H+-ATPase activity, through phosphorylation of the penultimate Thr, as well as induce elongation growth (Marrè 1979; Kinoshita and Shimazaki 2001). Fusicoccin added to the incubation medium in the same way as IAA, at a final concentration of 1 µM, enhanced the endogenous growth of maize coleoptile segments to a level comparable with growth seen in the presence of IAA (Fig. 2). Independently of the ionic composition of the medium, FC added at 2 h of segment preincubation caused rapid growth with bell-shaped kinetics (Fig. 3). In the absence of K+ in incubation medium (Fig. 3A), Ca2+ at 0.1 and 1 mM significantly inhibited FC-induced elongation growth (F2,23 = 12.79, P < 0.01) by 46 % compared with growth in medium without Ca2+ and K+ (3378.3 ± 338.6 µm cm−1; mean ± SE, n = 8, Fig. 3A, inset). In medium with 1 mM K+ and Ca2,+ at both concentrations, inhibition of FC-induced growth was significant (F2,25 = 4.07, P = 0.029) but did not exceed 25 % (Fig. 3B). As in the case of IAA, FC-induced growth in a medium containing 10 mM K+ did not depend on Ca2+ concentration (F2,24 = 0.215, P = 0.807) (Fig. 3C).Figure 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