Wheat grain yield on saline soils is improved by an ancestral Na super(+) transporter gene

• Published in: Nature biotechnology Vol. 30; no. 4; pp. 360 - 364
• Main Authors: Munns, Rana, James, Richard A, Xu, Bo, Athman, Asmini, Conn, Simon J, Jordans, Charlotte, Byrt, Caitlin S, Hare, Ray A, Tyerman, Stephen D, Tester, Mark, Plett, Darren, Gilliham, Matthew
• Format: Journal Article
• Language: English
• Published: 01.04.2012
• Subjects: Triticum aestivum; Triticum monococcum; Triticum turgidum
• ISSN: 1087-0156
• DOI: 10.1038/nbt.2120

The ability of wheat to maintain a low sodium concentration ([Na super(+)]) in leaves correlates with improved growth under saline conditions. This trait, termed Na super(+) exclusion, contributes to the greater salt tolerance of bread wheat relative to durum wheat. To improve the salt tolerance of durum wheat, we explored natural diversity in shoot Na super(+) exclusion within ancestral wheat germplasm. Previously, we showed that crossing of Nax2, a gene locus in the wheat relative Triticum monococcum into a commercial durum wheat (Triticum turgidum ssp. durum var. Tamaroi) reduced its leaf [Na super(+)] (ref. 5). Here we show that a gene in the Nax2 locus, TmHKT1; 5-A, encodes a Na super(+)-selective transporter located on the plasma membrane of root cells surrounding xylem vessels, which is therefore ideally localized to withdraw Na super(+) from the xylem and reduce transport of Na super(+) to leaves. Field trials on saline soils demonstrate that the presence of TmHKT1; 5-A significantly reduces leaf [Na super(+)] and increases durum wheat grain yield by 25% compared to near-isogenic lines without the Nax2 locus.