Plant Physiology Preview
Published on October 6, 2006; 10.1104/pp.106.086538
Received July 12, 2006
Accepted August 23, 2006
Physiological Characterisation of Two Genes for Na+ Exclusion in Durum Wheat: Nax1 and Nax2
Richard A. James *, Romola J. Davenport , and Rana Munns
Commonwealth Scientific and Industrial Research Organisation, Division of Plant Industry, GPO Box 1600, Canberra 2601, Australia
Department of Plant Sciences, Downing St Cambridge CB2 3EA, UK
* Corresponding author; email: richard.james{at}csiro.au.
Line 149 is a durum wheat (Triticum turgidum ssp. durum) that contains two novel major genes for excluding Na+ from leaf blades, named Nax1 and Nax2. The genes were separated into families containing a single gene, and near-isogenic homozygous lines were selected. Lines containing either Nax1 or Nax2 had lower rates of Na+ transport from roots to shoots than their near-isogenic pairs, due to lower rates of net loading of the xylem, not to lower rates of net uptake from the soil or higher rates of retranslocation in the phloem. Nax1 and Nax2 lines also had higher rates of K+ transport from root to shoot, resulting in an enhanced discrimination of K+ over Na+. Lines containing Nax1 differed from those containing Nax2 by unloading Na+ from the xylem as it entered the shoot, so that Na+ was retained in the base of the leaf, leading to a high sheath:blade ratio of Na+ concentration. Gradients in tissue concentrations of Na+ along the leaf suggested that Na+ was continually removed from the xylem. The Nax2 line did not retain Na+ in the base of the leaf, suggesting that it functioned only in the root. The Nax2 gene therefore has a homoeologous function to Kna1 in bread wheat.
This article has been cited by other articles:
|
|
|
|
 
Widodo, J. H. Patterson, E. Newbigin, M. Tester, A. Bacic, and U. Roessner
Metabolic responses to salt stress of barley (Hordeum vulgare L.) cultivars, Sahara and Clipper, which differ in salinity tolerance
J. Exp. Bot.,
October 1, 2009;
60(14):
4089 - 4103.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. S. Moller, M. Gilliham, D. Jha, G. M. Mayo, S. J. Roy, J. C. Coates, J. Haseloff, and M. Tester
Shoot Na+ Exclusion and Increased Salinity Tolerance Engineered by Cell Type-Specific Alteration of Na+ Transport in Arabidopsis
PLANT CELL,
July 1, 2009;
21(7):
2163 - 2178.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. C. Collins, F. Tardieu, and R. Tuberosa
Quantitative Trait Loci and Crop Performance under Abiotic Stress: Where Do We Stand?
Plant Physiology,
June 1, 2008;
147(2):
469 - 486.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Huang, W. Spielmeyer, E. S. Lagudah, and R. Munns
Comparative mapping of HKT genes in wheat, barley, and rice, key determinants of Na+ transport, and salt tolerance
J. Exp. Bot.,
March 5, 2008;
(2008)
ern033v1.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
H.-C. Jing, D. Kornyukhin, K. Kanyuka, S. Orford, A. Zlatska, O. P. Mitrofanova, R. Koebner, and K. Hammond-Kosack
Identification of variation in adaptively important traits and genome-wide analysis of trait marker associations in Triticum monococcum
J. Exp. Bot.,
October 1, 2007;
58(13):
3749 - 3764.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S.-M. Wang, J.-L. Zhang, and T. J. Flowers
Low-Affinity Na+ Uptake in the Halophyte Suaeda maritima
Plant Physiology,
October 1, 2007;
145(2):
559 - 571.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. S. Byrt, J. D. Platten, W. Spielmeyer, R. A. James, E. S. Lagudah, E. S. Dennis, M. Tester, and R. Munns
HKT1;5-Like Cation Transporters Linked to Na+ Exclusion Loci in Wheat, Nax2 and Kna1
Plant Physiology,
April 1, 2007;
143(4):
1918 - 1928.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Huang, W. Spielmeyer, E. S. Lagudah, R. A. James, J. D. Platten, E. S. Dennis, and R. Munns
A Sodium Transporter (HKT7) Is a Candidate for Nax1, a Gene for Salt Tolerance in Durum Wheat
Plant Physiology,
December 1, 2006;
142(4):
1718 - 1727.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
