Plant salinity tolerance is a polygenic trait with contributions from genetic, developmental, and physiological interactions, in addition to interactions between the plant and its environment. In this study, we show that in salt-tolerant genotypes of barley (Hordeum vulgare), multiple mechanisms are well combined to withstand saline conditions. These mechanisms include: (1) better control of membrane voltage so retaining a more negative membrane potential; (2) intrinsically higher H+ pump activity; (3) better ability of root cells to pump Na+ from the cytosol to the external medium; and (4) higher sensitivity to supplemental Ca2+. At the same time, no significant difference was found between contrasting cultivars in their unidirectional 22Na+ influx or in the density and voltage dependence of depolarization-activated outward-rectifying K+ channels. Overall, our results are consistent with the idea of the cytosolic K+-to-Na+ ratio being a key determinant of plant salinity tolerance, and suggest multiple pathways of controlling that important feature in salt-tolerant plants. © 2007 American Society of Plant Biologists.

Item Type:	Refereed Article
Research Division:	Agricultural and Veterinary Sciences
Research Group:	Crop and Pasture Production
Research Field:	Crop and Pasture Improvement (Selection and Breeding)
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Winter Grains and Oilseeds
Objective Field:	Barley
Author:	Chen, Z (Mr Zhonghua Chen)
Author:	Cuin, TA (Dr Tracey Cuin)
Author:	Zhou, M (Professor Meixue Zhou)
Author:	Newman, IA (Dr Ian Newman)
Author:	Shabala, SN (Professor Sergey Shabala)
ID Code:	49928
Year Published:	2007
Web of Science® Times Cited:	204
Deposited By:	Agricultural Science
Deposited On:	2007-08-01
Last Modified:	2009-08-06
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