A gradient of cytoplasmic free calcium a in growing rhizoid cells of Fucus serratus

Brownlee, Colin; Wood, John

doi:10.1038/320624a0

Cited by 172 publications

(65 citation statements)

References 20 publications

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“…4). We were unable to investigate the distribution of free Ca2+, but by extrapolation from recent work with pollen tubes and Fucus (Nobiling & Reiss, 1987;Brownlee & Wood, 1986) we would expect that to exhibit a similar distribution. The question is whether such gradients play a causal role in polarized extension, and the effects of A23187 supply a hint.…”

Section: Discussionmentioning

confidence: 97%

“…Key findings include the uptake of Ca2+ into the apex of pollen tubes and fucoid rhizoids (Jaffe et al, 1975a, b;Robinson & Jaffe, 1975); the dependence of extension on Ca2+ and its inhibition by reagents thought to block Ca2+ uptake (Picton & Steer, 1983Reiss & Herth, 1985;Kropf & Quatrano, 1987); and the demonstration of cytoplasmic Ca2+ gradients, maximum apically (Jaffe et al, 1975 b;Reiss & Herth, 1978, 1979Brownlee & Wood, 1986: Kropf & Quatrano, 1987Nobiling & Reiss, 1987). Ca2+ ions are thought to play a central role in regulating apical extension.…”

Section: Introductionmentioning

confidence: 99%

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Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Schmid

Harold

1988

Microbiology

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We report initial attempts to define the role of Ca2+ in the polarized extension of Neurospora crassa. Growth of the organism was diminished in media containing less than 1 mM-Ca2+; extension was more severely impaired than biomass synthesis, resulting in the formation of stubby, bulbous hyphae, even of spherical cells. Reduced extension and abnormal morphology were correlated with the loss of surface-bound Ca2+, probably associated with the cell wall. Intracellular Ca2+ may be represented by material that fluoresces brightly in the presence of chlortetracycline. Punctate fluorescent bodies and diffuse fluorescence were both arrayed in a longitudinal gradient, maximum apically. Addition of the calcium ionophore A23 187 induced dissipation of the fluorescence; concurrently, the hyphae lost as much as one half of their Ca2+ content. Extension continued almost unabated, but multiple branches quickly emerged from the apex. The observations suggest that a cytoplasmic Ca2+ gradient is not required for polarized extension, but may play a role in ensuring the dominance of the apex.

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Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Schmid

Harold

1988

Microbiology

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“…In addition, the rapid activation by H 2 O 2 of nonselective plasma membrane cation channels in cell-attached recordings strongly suggests that the initial action of external ROS production is mediated via Ca 2ϩ influx through these channels. It remains to be determined whether the production of ROS at the growing rhizoid apex also underlies the Ca 2ϩ gradient associated with rhizoid germination and growth (Brownlee and Wood, 1986;Taylor et al, 1996;Pu and Robinson, 1998). The concentrations of H 2 O 2 that elicited increases in Ca 2ϩ cyt (0.1 to 1.0 mM) are comparable to those shown to cause Ca 2ϩ increases and increased Ca 2ϩ current in stomatal guard cell protoplasts (Pei et al, 2000).…”

Section: Discussionmentioning

confidence: 99%

Spatiotemporal Patterning of Reactive Oxygen Production and Ca²⁺ Wave Propagation in Fucus Rhizoid Cells

et al. 2002

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“…Seals up to 5 GQ were obtained Figure 1E illustrates channel activity recorded on plasma membrane exposed at the tip region of a rhizoid cell. With the electrode clamped to 0 mV, the only major permeant ion that would carry the outward currents at the assumed transmembrane potential of -80 mV, based on recordings from intact zygotes (2,23), is K+. The outward currents represented by downward deflections in the cell-attached configuration are likely to be due to K+ channel activity.…”

Section: Electrophysiologymentioning

confidence: 99%

Localized Patch Clamping of Plasma Membrane of a Polarized Plant Cell

Taylor¹,

Brownlee²

1992

Plant Physiol.

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We used an ultraviolet laser to rupture a small region of cell wall of a polarized Fucus spiralis rhizoid cell and gained localized access to the plasma membrane at the growing apex. Careful control of cell turgor enabled a small portion of plasma membranebound cytoplasm to be exposed. (1,11,17,19,21), and more recently, the technique has been used to investigate their regulation (7,10,15,16,18,20).Removal of the cell wall to expose plasma membrane suitable for patch recording was predicted to be a major problem in the advancement of single-channel studies in plant cells by Takeda and coworkers (22). In all but a few cases, removal of the cell wall is achieved by enzymic treatment to produce a spherical protoplast. the low success rates have often proved unsuccessful (6), although recent improvements to the procedure of enzymically isolating protoplasts may increase the number of successful GU seals (4).Plant cell protoplasts do not retain the structural order or polarity of the parent cell. This problem is of particular importance in the study of ion channel activity, distribution, and regulation in polarizing and polarized plant cells. In Fucus zygotes, the plant cell wall is required for the axis of polarity to develop (13); protoplasts from young Fucus zygotes are, therefore, of limited use in a single-channel study of polarity because localized cell wall removal and exposure of the underlying plasmalemma is required. Furthermore, the extraction and purification of the enzymes required for cell wall removal in Fucus are complex and time consuming (12). Although mechanical or surgical techniques have been used to gain access to the plasmalemma of Chara (3, 14), these are not suitable for smaller and less robust cells.In this report, we describe a novel technique for localized removal of the cell wall of Fucus rhizoid cells using a UV laser. Under appropriate conditions of turgor, the tip of the rhizoid cell is exposed, enabling high resistance GO seals to be obtained on the plasmalemma. MATERIALS AND METHODS Growth of ZygotesThallus tips bearing mature conceptacles of the dioecious marine alga Fucus spiralis were collected, washed, and stored at 40C in the dark for 1 to 3 d before they were placed in FSW2 at 180C to release zygotes. Zygotes were washed and transferred into small plastic chambers with a glass coverslip base. Dishes were placed in unilateral white fluorescent light (50 ,Em-2 s-1) at 180C to promote polarization, and zygotes were used 2 to 3 d after release. Preparation of ZygotesDishes were placed on the stage of an inverted microscope (Nikon Diaphot, Nikon, Tokyo, Japan) and treated with

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A gradient of cytoplasmic free calcium a in growing rhizoid cells of Fucus serratus

Cited by 172 publications

References 20 publications

Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Spatiotemporal Patterning of Reactive Oxygen Production and Ca²⁺ Wave Propagation in Fucus Rhizoid Cells

Localized Patch Clamping of Plasma Membrane of a Polarized Plant Cell

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A gradient of cytoplasmic free calcium a in growing rhizoid cells of Fucus serratus

Cited by 172 publications

References 20 publications

Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Dual Roles for Calcium Ions in Apical Growth of Neurospora crassa

Spatiotemporal Patterning of Reactive Oxygen Production and Ca2+ Wave Propagation in Fucus Rhizoid Cells

Localized Patch Clamping of Plasma Membrane of a Polarized Plant Cell

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Product

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Spatiotemporal Patterning of Reactive Oxygen Production and Ca²⁺ Wave Propagation in Fucus Rhizoid Cells