Stringent control of cytoplasmic Ca2+ in guard cells of intact plants compared to their counterparts in epidermal strips or guard cell protoplasts

Levchenko V, Guinot DR, Klein M, Roelfsema MRG, Hedrich R, Dietrich P (2008)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2008

Journal

Protoplasma Springer Verlag (Germany)

Book Volume: 233

Pages Range: 61-72

Journal Issue: 1

DOI: 10.1007/s00709-008-0307-x

Abstract

Cytoplasmic calcium elevations, transients, and oscillations are thought to encode information that triggers a variety of physiological responses in plant cells. Yet Ca signals induced by a single stimulus vary, depending on the physiological state of the cell and experimental conditions. We compared Ca homeostasis and stimulus-induced Ca signals in guard cells of intact plants, epidermal strips, and isolated protoplasts. Single-cell ratiometric imaging with the Ca-sensitive dye Fura 2 was applied in combination with electrophysiological recordings. Guard cell protoplasts were loaded with Fura 2 via a patch pipette, revealing a cytoplasmic free Ca concentration of around 80 nM at -47 mV. Upon hyperpolarization of the plasma membrane to -107 mV, the Ca concentration increased to levels exceeding 400 nM. Intact guard cells were able to maintain much lower cytoplasmic free Ca concentrations at hyperpolarized potentials, the average concentration at -100 mV was 183 and 90 nM in epidermal strips and intact plants, respectively. Further hyperpolarization of the plasma membrane to -160 mV induced a sustained rise of the guard cell cytoplasmic Ca concentration, which slowly returned to the prestimulus level in intact plants but not in epidermal strips. Our results show that cytoplasmic Ca concentrations are stringently controlled in guard cells of intact plants but become increasingly more sensitive to changes in the plasma membrane potential in epidermal strips and isolated protoplasts. © 2008 Springer-Verlag.

Authors with CRIS profile

Petra Dietrich Professur für Zellbiologie der Pflanzen

Involved external institutions

Julius-Maximilians-Universität Würzburg DE Germany (DE) University of Zurich / Universität Zürich (UZH) CH Switzerland (CH)

How to cite

APA:

Levchenko, V., Guinot, D.R., Klein, M., Roelfsema, M.R.G., Hedrich, R., & Dietrich, P. (2008). Stringent control of cytoplasmic Ca2+ in guard cells of intact plants compared to their counterparts in epidermal strips or guard cell protoplasts. Protoplasma, 233(1), 61-72. https://doi.org/10.1007/s00709-008-0307-x

MLA:

Levchenko, V., et al. "Stringent control of cytoplasmic Ca2+ in guard cells of intact plants compared to their counterparts in epidermal strips or guard cell protoplasts." Protoplasma 233.1 (2008): 61-72.

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