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Oscillations in plant membrane transport: model predictions, experimental validation, and physiological implications


Shabala, SN and Shabala, L and Gradmann, D and Chen, Z and Newman, IA and Mancuso, S, Oscillations in plant membrane transport: model predictions, experimental validation, and physiological implications, Journal of Experimental Botany, 57, (1) pp. 171-184. ISSN 0022-0957 (2006) [Refereed Article]

DOI: doi:10.1093/jxb/erj022


Although oscillations in membrane-transport activity are ubiquitous in plants, the ionic mechanisms of ultradian oscillations in plant cells remain largely unknown, despite much phenomenological data. The physio logical role of such oscillations is also the subject of much speculation. Over the last decade, much experimental evidence showing oscillations in net ion fluxes across the plasma membrane of plant cells has been accumulated using the non-invasive MIFE technique. In this study, a recently proposed feedback-controlled oscillatory model was used. The model adequately describes the observed ion flux oscillations within the minute range of periods and predicts: (i) strong dependence of the period of oscillations on the rate constants for the H + pump; (ii) a substantial phase shift between oscillations in net H + and K + fluxes; (iii) cessation of oscillations when H + pump activity is suppressed; (iv) the existence of some 'window' of external temperatures and ionic concentrations, where non-damped oscillations are observed: outside this range, even small changes in external parameters lead to progressive damping and aperiodic behaviour; (v) frequency encoding of environmental information by oscillatory patterns; and (vi) strong dependence of oscillatory characteristics on cell size. All these predictions were successfully confirmed by direct experimental observations, when net ion fluxes were measured from root and leaf tissues of various plant species, or from single cells. Because oscillatory behaviour is inherent in feedback control systems having phase shifts, it is argued from this model that suitable conditions will allow oscillations in any cell or tissue. The possible physiological role of such oscillations is discussed in the context of plant adaptive responses to salinity, temperature, osmotic, hypoxia, and pH stresses. © The Author [2005]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Microbiology
Research Field:Microbial ecology
Objective Division:Health
Objective Group:Public health (excl. specific population health)
Objective Field:Food safety
UTAS Author:Shabala, SN (Professor Sergey Shabala)
UTAS Author:Shabala, L (Associate Professor Lana Shabala)
UTAS Author:Chen, Z (Mr Zhonghua Chen)
UTAS Author:Newman, IA (Dr Ian Newman)
ID Code:36719
Year Published:2006
Web of Science® Times Cited:66
Deposited By:Agricultural Science
Deposited On:2006-08-01
Last Modified:2007-04-18

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