Role of Ion Channels in Plants

Hedrich, Rainer; Geiger, Dietmar; Marten, Irene; Roelfsema, M. Rob G.

doi:10.1007/978-4-431-53993-3_19

Cited by 5 publications

(5 citation statements)

References 193 publications

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“…Vacuoles were released by selective osmotic shock and used for patch‐clamp studies within 15 min after liberation from the cellular context of the rice leaf. Patch pipettes were sealed on vacuoles and whole‐vacuole configuration was established by a punch‐through voltage pulse protocol (Hedrich et al ., ). Following access to the vacuole lumen and equilibration with pipette solution, ion species on the cytosolic side of the membrane and voltage protocols were chosen to selectively elicit SV currents.…”

Section: Resultsmentioning

confidence: 97%

On the cellular site of two‐pore channel TPC1 action in the Poaceae

et al. 2013

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SummaryThe slow vacuolar (SV) channel has been characterized in different dicots by patch-clamp recordings. This channel represents the major cation conductance of the largest organelle in most plant cells. Studies with the tpc1-2 mutant of the model dicot plant Arabidopsis thaliana identified the SV channel as the product of the TPC1 gene. By contrast, research on rice and wheat TPC1 suggested that the monocot gene encodes a plasma membrane calcium-permeable channel.To explore the site of action of grass TPC1 channels, we expressed OsTPC1 from rice (Oryza sativa) and TaTPC1 from wheat (Triticum aestivum) in the background of the Arabidopsis tpc1-2 mutant. Cross-species tpc1 complementation and patch-clamping of vacuoles using Arabidopsis and rice tpc1 null mutants documented that both monocot TPC1 genes were capable of rescuing the SV channel deficit.Vacuoles from wild-type rice but not the tpc1 loss-of-function mutant harbor SV channels exhibiting the hallmark properties of dicot TPC1/SV channels. When expressed in human embryonic kidney (HEK293) cells OsTPC1 was targeted to Lysotracker-Red-positive organelles.The finding that the rice TPC1, just like those from the model plant Arabidopsis and even animal cells, is localized and active in lyso-vacuolar membranes associates this cation channel species with endomembrane function.

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Section: Resultsmentioning

confidence: 97%

On the cellular site of two‐pore channel TPC1 action in the Poaceae

et al. 2013

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“…A range of Ca 2+ channels, K + channels, NSCC, and anion channels have been identified previously in Arabidopsis root epidermal PM through patch clamping (e.g., Demidchik et al, 2002; Foreman et al, 2003; Pilot et al, 2003; Diatloff et al, 2004; Demidchik et al, 2007; Demidchik et al, 2009; Hedrich et al, 2012; Laohavisit et al, 2012; Demidchik et al, 2014; Makavitskaya et al, 2018). Using the same experimental conditions as our previous study (which identified the eATP-activated small HACC-like and K + efflux conductances; Wang et al, 2018), 26 out of 113 protoplasts from the elongation zone epidermis were found to have a large time-dependent HACC conductance (Véry and Davies, 2000) under control conditions, which was accompanied by an instantaneous outward current at depolarized voltages ( Figure 1A ).…”

Section: Diverse Conductances In the Plasma Membrane Of Arabidopsis Rmentioning

confidence: 99%

“…The novel finding here of an eATP-activated anion conductance adds another component to eATP signaling. Plant PM anion fluxes can involve slow-activating and rapid-activating anion channels, provided by members of the sl ow a nion c hannel-associated (SLAC) and al uminum-activated m alate t ransporter (ALMT) families, respectively (Hedrich et al, 2012). At this point, an ALMT channel appears the most likely candidate for the eATP-activated anion channel, but members of the ATP-binding cassette superfamily should be considered given that mammalian ABC transporters can function as Cl − channels (Anderson et al, 1991).…”

Section: Future Directionsmentioning

confidence: 99%

Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process

et al. 2019

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Adenosine 5′-triphosphate (ATP) is an important extracellular signaling agent, operating in growth regulation, stomatal conductance, and wound response. With the first receptor for extracellular ATP now identified in plants (P2K1/DORN1) and a plasma membrane NADPH oxidase revealed as its target, the search continues for the components of the signaling cascades they command. The Arabidopsis root elongation zone epidermal plasma membrane has recently been shown to contain cation transport pathways (channel conductances) that operate downstream of P2K1 and could contribute to extracellular ATP (eATP) signaling. Here, patch clamp electrophysiology has been used to delineate two further conductances from the root elongation zone epidermal plasma membrane that respond to eATP, including one that would permit chloride transport. This perspective addresses how these conductances compare to those previously characterized in roots and how they might operate together to enable early events in eATP signaling, including elevation of cytosolic-free calcium as a second messenger. The role of the reactive oxygen species (ROS) that could arise from eATP’s activation of NADPH oxidases is considered in a qualitative model that also considers the regulation of plasma membrane potential by the concerted action of the various cation and anion conductances. The molecular identities of the channel conductances in eATP signaling remain enigmatic but may yet be found in the multigene families of glutamate receptor-like channels, cyclic nucleotide-gated channels, annexins, and aluminum-activated malate transporters.

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“…The patch-clamp technique has been the electrophysiological system of choice for gaining insight into metabolite and ion transport across the vacuolar membrane (Hedrich et al, 1986(Hedrich et al, , 2012Isayenkov et al, 2010). The ability to control the composition of solutions inside and outside the vacuole is a major advantage of this method.…”

Section: Sv (Tpc1) Channels In Vacuoles Of Intact Root Hair Cell Appementioning

confidence: 99%

“…During expansion, plant cells take up large amounts of ions, which are predominantly stored in the central vacuole (Isayenkov et al, 2010;Martinoia et al, 2012). The transport mechanisms that shuttle ions across the vacuolar membrane have been intensively investigated using the patch-clamp technique (Isayenkov et al, 2010;Hedrich et al, 2012), a method that allows ion transport properties of isolated vacuoles, or protoplasts, to be assessed in detail (Hedrich, 2012). These measurements have shown that the vacuolar membrane exhibits at least three types of calcium-regulated (TPK) channels (Bihler et al, 2005;Gobert et al, 2007;Latz et al, 2007Latz et al, , 2013Voelker et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Cytosolic Ca2+ Signals Enhance the Vacuolar Ion Conductivity of Bulging Arabidopsis Root Hair Cells

Wang

Dindas²,

Rienmüller³

et al. 2015

Molecular Plant

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Plant cell expansion depends on the uptake of solutes across the plasma membrane and their storage within the vacuole. In contrast to the well-studied plasma membrane, little is known about the regulation of ion transport at the vacuolar membrane. We therefore established an experimental approach to study vacuolar ion transport in intact Arabidopsis root cells, with multi-barreled microelectrodes. The subcellular position of electrodes was detected by imaging current-injected fluorescent dyes. Comparison of measurements with electrodes in the cytosol and vacuole revealed an average vacuolar membrane potential of -31 mV. Voltage clamp recordings of single vacuoles resolved the activity of voltage-independent and slowly deactivating channels. In bulging root hairs that express the Ca(2+) sensor R-GECO1, rapid elevation of the cytosolic Ca(2+) concentration was observed, after impalement with microelectrodes, or injection of the Ca(2+) chelator BAPTA. Elevation of the cytosolic Ca(2+) level stimulated the activity of voltage-independent channels in the vacuolar membrane. Likewise, the vacuolar ion conductance was enhanced during a sudden increase of the cytosolic Ca(2+) level in cells injected with fluorescent Ca(2+) indicator FURA-2. These data thus show that cytosolic Ca(2+) signals can rapidly activate vacuolar ion channels, which may prevent rupture of the vacuolar membrane, when facing mechanical forces.

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Role of Ion Channels in Plants

Cited by 5 publications

References 193 publications

On the cellular site of two‐pore channel TPC1 action in the Poaceae

On the cellular site of two‐pore channel TPC1 action in the Poaceae

Early Extracellular ATP Signaling in Arabidopsis Root Epidermis: A Multi-Conductance Process

Cytosolic Ca2+ Signals Enhance the Vacuolar Ion Conductivity of Bulging Arabidopsis Root Hair Cells

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