HKT1;5-Like Cation Transporters Linked to Na + Exclusion Loci in Wheat, Nax2 and Kna1

作者：Caitlin Siobhan Byrt, John Damien Platten, Wolfgang Spielmeyer, Richard A. James, Evans S. Lagudah, Elizabeth S. Dennis, Mark A. Tester, Rana Munns · 发表于：PLANT PHYSIOLOGY · 年份：2007 · DOI：10.1104/pp.106.093476 · 被引用次数：411 · 研究领域：Plant nutrient uptake and metabolism、Plant Stress Responses and Tolerance、Plant Micronutrient Interactions and Effects

Bread wheat (Triticum aestivum) has a greater ability to exclude Na+ from its leaves and is more salt tolerant than durum wheat (Triticum turgidum L. subsp. durum [Desf.]). A novel durum wheat, Line 149, was found to contain a major gene for Na+ exclusion, Nax2, which removes Na+ from the xylem in the roots and leads to a high K+-to-Na+ ratio in the leaves. Nax2 was mapped to the distal region on chromosome 5AL based on linkage to microsatellite markers. The Nax2 locus on 5AL coincides with the locus for a putative Na+ transporter, HKT1;5 (HKT8). The Nax2 region on 5AL is homoeologous to the region on chromosome 4DL containing the major Na+ exclusion locus in bread wheat, Kna1. A gene member of the HKT1;5 family colocates to the deletion bin containing Kna1 on chromosome 4DL. This work provides evidence that Nax2 and Kna1 are strongly associated with HKT1;5 genes.