Aktionsstr�me der Blasen vonUtricularia vulgaris

Diannelidis, Themistokles; Ümrath, Karl

doi:10.1007/bf01248655

Cited by 13 publications

(11 citation statements)

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“…Dianne1idis (1948) also showed that the inside of the bladder of U. vulgaris was electrically positive with respect to the external medium. Diannelidis and Umrath (1953) measured a potential difference (p.d.) of 104 m V between the interior and exterior of the bladder of U. vulgaris, and a p.d.…”

Section: Introductionmentioning

confidence: 99%

The Rapid Movement of the Bladder of Utricularia Sp

Sydenham¹,

Findlay²

1973

Aust. Jnl. Of Bio. Sci.

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The changes which occur in the internal pressure, volume, membrane potential difference (p.d.), and membrane resistance during the firing of bladders of Utricularia sp. are described.Firing of a bladder leads to an increase in the internal hydrostatic pressure from about -17 kPa to about -5 kPa and an increase in luminal volume of more than 40 %. Application of the Nernst equilibrium equation indicates that in a set bladder sodium and potassium ions are actively transported into the lumen from the outside solution and that chloride ions are actively transported in the reverse direction. Furthermore, sodium and potassium ions must be actively transported from the cells of the bladder wall into the lumen and probably chloride ions are actively transported in the opposite direction.Although it has generally been considered that the firing process is a purely mechanical one there is some evidence for the existence of an excitatory step. Various aspects of this process are discussed.

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Section: Introductionmentioning

confidence: 99%

The Rapid Movement of the Bladder of Utricularia Sp

Sydenham¹,

Findlay²

1973

Aust. Jnl. Of Bio. Sci.

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“…As probably the most extreme embodiment of the carnivorous syndrome [3], all species are completely rootless, and at least all aquatic species feature a suction trap mechanism that relies on a release of stored elastic energy in the trap body. Entailing a cascade of fast motions [6][7][8][9][10][11][12][13][14][15], the whole trapping action is too fast to be followed with the naked eye. Yet there are no detailed camera recordings available, and the exact motion pattern has been unclear until now.…”

Section: Introductionmentioning

confidence: 99%

Ultra-fast underwater suction traps

et al. 2011

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Carnivorous aquatic Utricularia species catch small prey animals using millimetre-sized underwater suction traps, which have fascinated scientists since Darwin's early work on carnivorous plants. Suction takes place after mechanical triggering and is owing to a release of stored elastic energy in the trap body accompanied by a very fast opening and closing of a trapdoor, which otherwise closes the trap entrance watertight. The exceptional trapping speed-far above human visual perception-impeded profound investigations until now. Using high-speed video imaging and special microscopy techniques, we obtained fully time-resolved recordings of the door movement. We found that this unique trapping mechanism conducts suction in less than a millisecond and therefore ranks among the fastest plant movements known. Fluid acceleration reaches very high values, leaving little chance for prey animals to escape. We discovered that the door deformation is morphologically predetermined, and actually performs a buckling/unbuckling process, including a complete trapdoor curvature inversion. This process, which we predict using dynamical simulations and simple theoretical models, is highly reproducible: the traps are autonomously repetitive as they fire spontaneously after 5 -20 h and reset actively to their ready-to-catch condition.

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“…The existence of static cell transmembrane potentials in higher plants is well established (4,6,12). The static transmembrane potential is the resting potential of a polarized cell which for large cells can be measured across the membrane by means of a high impedance voltmeter.…”

Section: Introductionmentioning

confidence: 99%

“…The existence of static cell transmembrane potentials in higher plants is well established (4,6,12 where Es, is the transmembrane potential, R the gas-constant, T the absolute temperature, z the charge on the ions in question, F the Faraday constant, and C, and Ci the ion concentrations outside and inside the cell membrane, respectively. However, it is impossible by means of this technique to measure short term variations such as the action potentials generated by the cell depolarization-repolarization process.…”

mentioning

confidence: 99%

“…This stimulus may be a simple one such as simply punching a hole in the cell (1) or sending an electrical current through the cell. Also, stimulated action potential generation in higher plants by means of an electrical current passing through the tissue has been investigated (12).The existence of static cell transmembrane potentials in higher plants is well established (4,6,12). The static transmembrane potential is the resting potential of a polarized cell which for large cells can be measured across the membrane by means of a high impedance voltmeter.…”

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confidence: 99%

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Nonrandom Bioelectrical Signals in Plant Tissue

Karlsson¹

1972

Plant Physiol.

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The results of investigations on nonevoked bioelectrical activity in the India-rubber tree (Ficus elastica) are presented. Metal electrodes inserted into the plant issue were used as the ionic-to-electronic conduction converting elements. Nonevoked pulse bursts were observed with amplitudes in the 10 to 200 microvolts range. An upper limit value of the cell refractory period has been estimated from the maximum pulse frequency observed.The existence of evoked action potentials in plants due to a stimulation of the cell depolarization-repolarization process is well established. The concept of stimulation covers a broad range of interactions between the cell and its environment. In some cases the act of observation might be considered a stimulation in itself because of the interaction present during the observation. The general bioelectrical measurement situation is influenced by the not negligible interaction between the measurement apparatus and the object under investigation.In the present work, measurements have been made of nonevoked bioelectrical signals in the tissue of the India-rubber tree (Ficus elastica). Nonevoked in this case means that no stimulus was applied to the plant except for the presence of the electrodes in the petioles and the bias current of the amplifiers which is less than 10" amp. Bursts of pulses with well defined and rather constant amplitudes have been found to be produced by bioelectrical generators located in the plant tissue. Pulse burst lengths ranging from 30 sec to 25 min have been observed. The frequency of occurrence of the pulses within the burst is in the 0.5 to 200 pulses per minute range. Great effort was made to ensure that pulses generated by sources external to the plant were not mistaken for signals generated in the plant. Because of the electrode arrangement used, the pulses observed are assumed to represent the cellular action potential produced by groups of cells, analogous to the extracellular action potential as defined in medical electrophysiology (3). This assumption is substantiated by the fact that, while the single plant cell polarization-depolarization action potential has an amplitude of about 70 mv (6,14), the potentials measured in the course of the present work were all in the 10 to 200 /tv range. A difference in amplitude of the same order of magnitude between the intra-and extra-cellular action potentials is also found in medical electrophysiology (1 1).As in animal tissue, the electrical activity in plant tissue is based on ion transport mechanisms (8). Due to this circumstance, it is necessary to make a conversion from the ionic conduction present in the tissue to the electronic conduction which occurs in the measuring circuit, in order to measure electrical effects in the plant tissue. This conversion is accomplished at the tissue-electrode interface. The electrodes should preferably perform this conversion without disturbing the ionic concentrations or permanently damaging the plant tissue. In the present work, metal electrodes made of stai...

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Aktionsstr�me der Blasen vonUtricularia vulgaris

Cited by 13 publications

References 2 publications

The Rapid Movement of the Bladder of Utricularia Sp

The Rapid Movement of the Bladder of Utricularia Sp

Ultra-fast underwater suction traps

Nonrandom Bioelectrical Signals in Plant Tissue

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