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Osmotic sensitivity of Ca2+ and H+ transporters in corn roots: Effect on fluxes and their oscillations in the elongation region

Citation

Shabala, SN and Newman, IA, Osmotic sensitivity of Ca2+ and H+ transporters in corn roots: Effect on fluxes and their oscillations in the elongation region, The Journal of Membrane Biology, 161, (1) pp. 45-54. ISSN 0022-2631 (1998) [Refereed Article]

DOI: doi:10.1007/s002329900313

Abstract

Seedling roots of cam were treated with different concentrations of mannitol-containing solution for 1 to 1.5 hr, and net fluxes of Ca2+ and H+ were measured in the elongation region. H+ fluxes were much more sensitive to osmotic pressure than were Ca2+ fluxes. Oscillations of 7-min period in H+ flux, normally observed in the control, were almost fully suppressed at high osmotic concentrations. Net H+ flux was shifted from average efflux of 25 ± 3 nmol m-2 sec-1 to average influx of 10 ± 5 nmol m-2 sec-1 after the incubation in 100 mM mannitol. The larger the osmotic concentration, the larger was the H+ influx. This flux caused the unbuffered solution of pH 4.85 to change to pH 5.3 after mannitol application, It appears that the osmoticum suppresses oscillatory H+ extrusion at the plasma membrane. Discrete Fourier Transforms of the H+ flux data showed that, apart from suppression of the 7-min oscillations in H+ flux, mannitol also promoted the appearance of faster 2-min oscillations. Ca2+ influx slightly increased after mannitol treatment. In addition the 7-min oscillatory component of Ca2+ flux remained apparent thereby showing independence of H+ flux.

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Other Physical Sciences
Research Field:Biological Physics
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Physical Sciences
Author:Shabala, SN (Professor Sergey Shabala)
Author:Newman, IA (Dr Ian Newman)
ID Code:13569
Year Published:1998
Web of Science® Times Cited:32
Deposited By:Physics
Deposited On:1998-08-01
Last Modified:2011-08-08
Downloads:0

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