The amino acid content increases substantially in salt-stressed plants. The physiological relevance of this phenomenon remains largely unknown. Using the MIFE ion flux measuring technique, we studied the effects of physiologically relevant concentrations of 26 amino acids on NaCl-induced K+ flux from barley root epidermis. We show that 21 (of 26) amino acids caused a significant mitigation of the NaCl-induced K+ efflux, while valine and ornithine substantially enhanced the detrimental effects of salinity on K+ homeostasis. Our results suggest that physiologically relevant concentrations of free amino acids might contribute to plant adaptive responses to salinity by regulating K+ transport across the plasma membrane, thus enabling maintenance of an optimal K+/Na+ ratio as opposed to being merely a symptom of plant damage by stress. Investigating the specific mechanisms of such amelioration remains a key issue for future studies. © 2006 Springer-Verlag.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant physiology
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Grains and seeds
Objective Field:	Barley
UTAS Author:	Cuin, TA (Dr Tracey Cuin)
UTAS Author:	Shabala, SN (Professor Sergey Shabala)
ID Code:	39839
Year Published:	2007
Web of Science® Times Cited:	112
Deposited By:	Agricultural Science
Deposited On:	2007-08-01
Last Modified:	2009-09-22
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