Figure 1.

Phylogenetic tree of Na⁺/H⁺ antiporters. Sequence analysis was performed online using Mobyle (http://mobyle.pasteur.fr/). A multiple sequence alignment of several antiporter protein sequences was generated using ClustalW and the neighbour-joining method was used to calculate evolutionary distances. The unrooted phylogenetic tree was constructed using the FigTree software package (FigTree 1.2.2, http://tree.bio.ed.ac.uk/software/figtree/). Antiporter sequences from the following species were used in the construction of the tree: Atriplex dimorphostegia (AdNHX1, AY211397), Atriplex gmelini (AgNHX1, AB038492), Arabidopsis thaliana (AtNHX1, NM_122597; AtNHX2, NM_111375; AtNHX3, NM_124929; AtNHX4, NM_111512; AtNHX5, NM_104315; AtNHX6, NM_106609), Brassica napus (BnNHX1, AY189676), Chenopodium glaucum (CgNHX1, AY371319), Citrus reticulata (CrNHX1, AY607026), Gossypium hirsutum (GhNHX1, AF515632), Glycine max (GmNHX1, AY972078), Hordeum vulgare (HvNHX1, AB089197), Kalidium foliatum (KfNHX1, AY825250), Limonium gmelinii (LgNHX1, EU780457), Mesembryanthemum crystallinum (McNHX1, AM746985; McNHX2, AM748092), Medicago sativa (MsNHX1, AY456096), Oryza sativa (OsNHX1, AB021878), Populus euphratica (PeNHX2, EU382999), Petunia hybrida (PhNHX1, AB051817), Plantago maritima (PmNHX1, EU233808), Populus tomentosa (PtNHX1, AY660749), Rosa hybrida (RhNHX1, AB199912), Salicornia brachiata (SbNHX1, EU448383), Salicornia europaea (SeNHX1, AY131235), Suaeda japonica (SjNHX1, AB198178), Solanum lycopersicum (SlNHX1, AJ306630; SlNHX2, AJ306631), Suaeda salsa (SsNHX1, AY261806), Tetragonia tetragonioides (TtNHX1, AF527625), Thellungiella halophila (ThNHX1, FJ713100), Triticum aestivum (TaNHX1, AY461512), Vitis vinifera (VvNHX1, AY634283), Zea mays (ZmNHX1, NM_001111751). The shaded area represents halophytic species.