Active chloride transport in the leaf epidermis of Commelina communis in relation to stomatal activity

Penny, M. G.; Kelday, L. S.; Bowling, D. J. F.

doi:10.1007/bf00387835

Cited by 40 publications

(19 citation statements)

References 8 publications

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“…We can assume that the number of osmotically active particles in the cell is proportional to the number of nondiffusible charges. The linearity found leads to the conclusion that in C. communis, solute content and stomatal aperture are linearly related to each other, much like in guard cells of V. faba for which the same conclusion was reached from results of an investigation employing a method quite different from the one used here (18 (Table I) did not reflect the differences in ionic activities Penny et al (14,15) determined between cells of open and those of closed stomata. So far we attempted to relate vacuolar potentials in the guard cells to ion activities.…”

Section: Vacuolar and Intraceflular Potentials In Relation To Stomatalsupporting

confidence: 69%

“…Ltd., [8][9][10][11][12][13][14][15][16][17][18][19][20][21] Shingikan-Cho, Nishinomiya, Japan). After digestion periods of 0, 1.5, and 3 to 5 h, electrical potential measurements of guard cells were performed in an identical bathing solution minus enzyme, then returned to the enzyme solution for further digestion, if any.…”

Section: Methodsmentioning

confidence: 99%

“…Micropipettes having a tip potential difference greater than 10 mv between immersion in 30 mm and 3.0 M KCI solutions were discarded. Corrections for tip potential changes upon penetrations of guard cells were made assuming that the protoplasm of guard cells from open and closed stomata was approximately equivalent to 500 and 100 mm KCL respectively (14,15 (Table II). The pomential gradient vanished when stomata closed (Table I), and in all epidermal cells the cytoplasmic potentials were then between 2 and 5 mv more negative than the vacuolar potentials.…”

Section: Methodsmentioning

confidence: 99%

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Electrical Potentials in Stomatal Complexes

Saftner

Raschke²

1981

Plant Physiol.

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MATERIALS AND METHODSPlants and Preparation of Epyermal Samples. Plants of C. communis L. were grown in growth chambers (22/20 C day/night; 85% RH; 14.5 h light; 85 w m-2 from fluorescent tubes, General Electric FR96T12-CW-1500). The first and second fully expanded leaves were removed from the tip of a branch and the basal half of each leaf was cut into two longitudinal sections. These sections were floated, with the abaxial side up, on distilled H20 for 3 to 6 h either in the light (85 w m 2 from mercury vapor lamps, General Electric H 400

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Section: Vacuolar and Intraceflular Potentials In Relation To Stomatalsupporting

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Electrical Potentials in Stomatal Complexes

Saftner

Raschke²

1981

Plant Physiol.

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“…

ABSTRACT (4,6). The cell walls of the epidermis may also receive and store inorganic ions, although there is doubt whether their capacity suffices (5).

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confidence: 99%

Release of Malate from Epidermal Strips during Stomatal Closure

Kirk

Raschke²

1978

Plant Physiol.

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(4,6). The cell walls of the epidermis may also receive and store inorganic ions, although there is doubt whether their capacity suffices (5). The fate of the organic anions during stomatal closure has been studied after 14C labeling of guard cell contents (2). Epidermal samples were exposed to 4C02 for 2 min and then subjected to closing treatments. The analysis of the epidermes as well as of the liquid on which they floated indicated that guard cells may dispose of malate in three ways: (a) catabolism in the tricarboxylic acid cycle; (b) decarboxylation followed by gluconeogenesis and starch formation; and (c) release from the guard cells. However, it was estimated that only a small fraction of the total malate pool was labeled in these experiments. To determine the extent to which these three methods are employed by guard cells during stomatal closure, the fate of the whole malate pool must be examined. In particular, the importance of a specific release of malate was to be assessed because this mechanism would enable guard cells to reduce their turgor faster than metabolism of malic acid would allow (2). Changes in malate content were followed during stomatal closure in epidermal samples and in the water on which they floated. In most cases, stomatal closing was induced by addition of ABA to the water. described elsewhere (7). The second, third, and fourth fully expanded leaves were removed, rinsed with distilled H20, and cut into sections of I to 3 x 2 to 4 cm2. These sections were floated lower side up on distilled H20 in the light (85 w m-2 from mercury vapor lamps, General Electric H400 RDX 33-1) and C02-free air for 4 to 5 hr to allow stomata to open. Then the lower epidermis was removed in strips of about 5 x 10 to 15 mm2. Sixty to 80%o of the ordinary epidermal cells ruptured during peeling. The area of each strip was measured with a ruler. In four of five strips/experiment, stomatal apertures were measured under the microscope; then these strips were plunged into boiling 80%o ethanol to extract malate. The other strips were transferred to distilled H20 or solutions containing ABA. After incubation for various times, the strips were put on a microscope slide for the measurement of 20 to 25 stomatal apertures in each strip and then immediately extracted with boiling ethanol. The extracts were evaporated to dryness and analyzed for malate by enzymical oxidation, coupled to the reduction of NAD; the NADH formed was measured fluorimetrically (3; for details see 7). The solutions on which the strips had floated were also evaporated and assayed for malate.RESULTS AND DISCUSSION Epidermal strips of V. faba with open stomata were exposed in the light to a 0.1 mm solution of (±)-ABA for periods of 15 min to 2 hr (Fig. 1)

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“…Guard cell K concentration changes several hundred millimolar during opening (2,10,12,13). Some of the K ion uptake is electrically balanced by chloride influx (12,14,15) but the bulk of it is balanced by release of protons during malate and citrate synthesis (10). Thus, anion synthesis in guard cells plays a key role in stomatal functioning.…”

mentioning

confidence: 99%