Present address: Lanzhou Institute of Animal Science and Veterinary Pharmaceutics Science, CAAS, Lanzhou 730050, China.
Puccinellia tenuiflora maintains a low Na+ level under salinity by limiting unidirectional Na+ influx resulting in a high selectivity for K+ over Na+
Article first published online: 22 JAN 2009
© 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd
Plant, Cell & Environment
Volume 32, Issue 5, pages 486–496, May 2009
How to Cite
WANG, C.-M., ZHANG, J.-L., LIU, X.-S., LI, Z., WU, G.-Q., CAI, J.-Y., FLOWERS, T. J. and WANG, S.-M. (2009), Puccinellia tenuiflora maintains a low Na+ level under salinity by limiting unidirectional Na+ influx resulting in a high selectivity for K+ over Na+. Plant, Cell & Environment, 32: 486–496. doi: 10.1111/j.1365-3040.2009.01942.x
- Issue published online: 7 APR 2009
- Article first published online: 22 JAN 2009
- Received 29 August 2008; received in revised form 29 October 2008; accepted for publication 23 December 2008
- selective absorption for K+ over Na+;
- selective transport for K+ over Na+;
- unidirectional 22Na+ influx and efflux
Puccinellia tenuiflora is a useful monocotyledonous halophyte that might be used for improving salt tolerance of cereals. This current work has shown that P. tenuiflora has stronger selectivity for K+ over Na+ allowing it to maintain significantly lower tissue Na+ and higher K+ concentration than that of wheat under short- or long-term NaCl treatments. To assess the relative contribution of Na+ efflux and influx to net Na+ accumulation, unidirectional 22Na+ fluxes in roots were carried out. It was firstly found that unidirectional 22Na+ influx into root of P. tenuiflora was significantly lower (by 31–37%) than in wheat under 100 and 150 mm NaCl. P. tenuiflora had lower unidirectional Na+ efflux than wheat; the ratio of efflux to influx was similar between the two species. Leaf secretion of P. tenuiflora was also estimated, and found the loss of Na+ content from leaves to account for only 0.0006% of the whole plant Na+ content over 33 d of NaCl treatments. Therefore, it is proposed that neither unidirectional Na+ efflux of roots nor salt secretion by leaves, but restricting unidirectional Na+ influx into roots with a strong selectivity for K+ over Na+ seems likely to contribute to the salt tolerance of P. tenuiflora.