title: HKT1;5-like cation transporters linked to Na+ exclusion loci in wheat, Nax2 and Kna1.
abstract: 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.
authors.affiliation: Commonwealth Scientific and Industrial Research Organization Plant Industry, Canberra, Australian Capital Territory 2601, Australia. caitlin.byrt@csiro.au
authors.forename: Caitlin S
authors.initials: CS
authors.lastname: Byrt
authors.forename: J Damien
authors.initials: JD
authors.lastname: Platten
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Spielmeyer
authors.forename: Richard A
authors.initials: RA
authors.lastname: James
authors.forename: Evans S
authors.initials: ES
authors.lastname: Lagudah
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Dennis
authors.forename: Mark
authors.initials: M
authors.lastname: Tester
authors.forename: Rana
authors.initials: R
authors.lastname: Munns
mesh_terms: D000483:Alleles; D001483:Base Sequence; D027682:Cation Transport Proteins / Q000378:metabolism*; D002412:Cations; D017931:DNA Primers; D017343:Genes, Plant; D014644:Genetic Variation; D017136:Ion Transport; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism*; D011123:Polyploidy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012964:Sodium / Q000378:metabolism*; D027981:Symporters / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism*
chemical_list: D027682:Cation Transport Proteins; D002412:Cations; D017931:DNA Primers; C088864:HKT1 protein, plant; D010940:Plant Proteins; D027981:Symporters; D012964:Sodium