Suppression of the plasma membrane H+-conductance on the background of high H+-pump activity in dithiothreitol-treated Chara cells

Dodonova, S.O.; Krupenina, Natalia A.; Булычев, А. А.

doi:10.1134/s1990747810040094

Cited by 7 publications

(4 citation statements)

References 26 publications

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“…4 of Beilby and Casanova 2014 ). As described in the “ Introduction ”, ROS signaling is implicated (Eremin et al 2013 ; Dodonova et al 2010 ; Li et al 2007 ; Beilby et al 2014 ). The random distribution of the alkaline spots over the cell surface (Figs.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, exposure of Chara cell to DTT (dithiothreitol) diminished the alkaline regions. A closure of H + /OH − channels by the reduction of disulfide bonds was assumed (Dodonova et al 2010 ). The pretreatment of Chara cells in potent antioxidant melatonin delayed the appearance of the saline noise upon exposure to saline stress (Beilby et al 2014 ).…”

Section: Introductionmentioning

confidence: 99%

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Surface pH changes suggest a role for H+/OH− channels in salinity response of Chara australis

Absolonova

Beilby²,

Hoepflinger

et al. 2017

Protoplasma

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To understand salt stress, the full impact of salinity on plant cell physiology has to be resolved. Electrical measurements suggest that salinity inhibits the proton pump and opens putative H+/OH− channels all over the cell surface of salt sensitive Chara australis (Beilby and Al Khazaaly 2009; Al Khazaaly and Beilby 2012). The channels open transiently at first, causing a characteristic noise in membrane potential difference (PD), and after longer exposure remain open with a typical current-voltage (I/V) profile, both abolished by the addition of 1 mM ZnCl2, the main known blocker of animal H+ channels. The cells were imaged with confocal microscopy, using fluorescein isothiocyanate (FITC) coupled to dextran 70 to illuminate the pH changes outside the cell wall in artificial fresh water (AFW) and in saline medium. In the early saline exposure, we observed alkaline patches (bright fluorescent spots) appearing transiently in random spatial distribution. After longer exposure, some of the spots became fixed in space. Saline also abolished or diminished the pH banding pattern observed in the untreated control cells. ZnCl2 suppressed the alkaline spot formation in saline and the pH banding pattern in AFW. The osmotic component of the saline stress did not produce transient bright spots or affect banding. The displacement of H+ from the cell wall charges, the H+/OH− channel conductance/density, and self-organization are discussed. No homologies to animal H+ channels were found. Salinity activation of the H+/OH− channels might contribute to saline response in roots of land plants and leaves of aquatic angiosperms.Electronic supplementary materialThe online version of this article (10.1007/s00709-017-1191-z) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Surface pH changes suggest a role for H+/OH− channels in salinity response of Chara australis

Absolonova

Beilby²,

Hoepflinger

et al. 2017

Protoplasma

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“…The pH banding system is transiently suppressed by passage of an action potential. The conductance in alkaline zones decreases, with recovery between 15–30 min ( Bulychev and Krupenina 2009 , Dodonova et al 2010 , for review see Beilby and Bisson 2012 ). Smith and Beilby (1983) measured transient decrease of conductance after an action potential (averaged over the whole cell).…”

Section: Introductionmentioning

confidence: 99%

“…What activates the OH − transporters at low pH o of 7? Reactive oxygen species (ROS) signalling might be involved ( Eremin et al 2013 ; Dodonova et al 2010 ; Li et al 2007 ). Pre-treatment of cells in antioxidant melatonin postponed the membrane PD noise upon the exposure to saline ( Beilby et al 2014 ).…”

Section: Introductionmentioning

confidence: 99%

The molecular identity of the characean OH− transporter: a candidate related to the SLC4 family of animal pH regulators

et al. 2021

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Characeae are closely related to the ancient algal ancestors of all land plants. The long characean cells display a pH banding pattern to facilitate inorganic carbon import in the acid zones for photosynthetic efficiency. The excess OH−, generated in the cytoplasm after CO2 is taken into the chloroplasts, is disposed of in the alkaline band. To identify the transporter responsible, we searched the Chara australis transcriptome for homologues of mouse Slc4a11, which functions as OH−/H+ transporter. We found a single Slc4-like sequence CL5060.2 (named CaSLOT). When CaSLOT was expressed in Xenopus oocytes, an increase in membrane conductance and hyperpolarization of resting potential difference (PD) was observed with external pH increase to 9.5. These features recall the behavior of Slc4a11 in oocytes and are consistent with the action of a pH-dependent OH−/H+ conductance. The large scatter in the data might reflect intrinsic variability of CaSLOT transporter activation, inefficient expression in the oocyte due to evolutionary distance between ancient algae and frogs, or absence of putative activating factor present in Chara cytoplasm. CaSLOT homologues were found in chlorophyte and charophyte algae, but surprisingly not in related charophytes Zygnematophyceae or Coleochaetophyceae.

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Membrane Excitation and Cytoplasmic Streaming as Modulators of Photosynthesis and Proton Flows in Characean Cells

Булычев

2012

Plant Electrophysiology

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Suppression of the plasma membrane H+-conductance on the background of high H+-pump activity in dithiothreitol-treated Chara cells

Cited by 7 publications

References 26 publications

Surface pH changes suggest a role for H+/OH− channels in salinity response of Chara australis

Surface pH changes suggest a role for H+/OH− channels in salinity response of Chara australis

The molecular identity of the characean OH− transporter: a candidate related to the SLC4 family of animal pH regulators

Membrane Excitation and Cytoplasmic Streaming as Modulators of Photosynthesis and Proton Flows in Characean Cells

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