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Effect of calcium on root development and root ion fluxes in salinised barley seedlings

Citation

Shabala, SN and Shabala, L and Van Volkenburgh, E, Effect of calcium on root development and root ion fluxes in salinised barley seedlings, Functional Plant Biology, 30, (5) pp. 507-514. ISSN 1445-4408 (2003) [Refereed Article]

DOI: doi:10.1071/FP03016

Abstract

The effects of various Na/Ca ratios on root growth, development, and ion acquisition patterns were studied in hydroponic experiments with barley (Hordeum vulgare L.) plants. In total, interactions between three different levels of salinity (1, 50 and 100 mM NaCl) and three different levels of Ca2+ (0.1, 1 and 10 mM) were studied (a full factorial experiment). Growth rate and biomass accumulation were significantly lower in salinised roots. In addition to reduction in extension growth, salinity also significantly affected plant developmental processes (for example reduced root hair density and root thickening). Supplemental Ca2+ significantly ameliorated those detrimental effects of salinity. Non-invasive, microelectrode ion-flux (MIFE) measurements showed that the onset of salt stress caused rapid and prolonged efflux of H+, K+ and NH4 + from the root epidermis. This efflux could be significantly reversed, or completely prevented, by the presence of high Ca2+ concentration in the bath solution, even after several days of salt stress. Membrane potential measurements in root epidermal cells showed that high Ca2+ levels in the bath were able to restore (otherwise depolarised) membrane potential back to control level (-120 to -130 mV). At the same time, no significant impact of Ca2+ on net Na+ uptake in plant roots was found. Some limitations of the MIFE technique for study of Na+ uptake kinetics under saline conditions, as well as possible ionic mechanisms underlying the ameliorating Ca2+ effects on ion fluxes in roots of salt-stressed plants, are discussed.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Plant Biology
Research Field:Plant Physiology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Shabala, SN (Professor Sergey Shabala)
Author:Shabala, L (Dr Lana Shabala)
ID Code:26896
Year Published:2003
Web of Science® Times Cited:131
Deposited By:Agricultural Science
Deposited On:2003-08-01
Last Modified:2004-04-21
Downloads:0

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