Phylogenetic tree of DOMON-containing proteins from Arabidopsis and rice and AIR12 sequences from diverse higher plants. The unrooted tree was constructed with the ClustalX2 program. Species abbreviations and full names: Al, Arabidopsis lyrata; At, Arabidopsis thaliana; Bc, Brassica carinata; Bn, Brassica napus (rapeseed); Br, Brassica rapa; Cc, Citrus clementina (mandarin); Cs, Citrus sinensis (orange); Gm, Glycine max (soybean); Gh, Gossypium hirsutum (cotton); Hv, Hordeum vulgare (barley); Le, Lycopersicon esculentum (tomato); Md, Malus domestica (apple); Mt, Medicago truncatula; Nt, Nicotiana tabacum (tobacco); Os, Oryza sativa ‘japonica’ group (rice); Pt, Populus trichocarpa (poplar); Rr, Raphanus raphanistrum (wild radish); Rs, Raphanus sativus (radish); Sb, Sorghum bicolor; St, Solanum tuberosum (potato); Vv, Vitis vinifera (grape vine); Zm, Zea mays (maize). For At and Os, the name of each protein in the tree corresponds to the locus number. AIR12 protein IDs from other sequenced genomes (http://genome.jgi-psf.org): Al (Araly1:478059), GmAIR12-1 (Glyma03g22260), GmAIR12-2 (Glyma16g09760), PtAIR12 (Poptr1_1:553231), and SbAIR12 (Sorbi1:4987942). AIR12 sequences accessible in NCBI entrez database (http://www.ncbi.nlm.nih.gov): Bc (ABS30419), Hv (AK248372), Vv (CAN67699), ZmAIR12-1 (ACG26288), and ZmAIR12-2 (ACG46823). AIR12 sequences translated from unigene clusters (http://www.ncbi.nlm.nih.gov/unigene): Bn (Bna14612), Br (Bra5828), Cc (Ccl16205), Cs (Csi4349), GhAIR12-1 (Ghi14385), GhAIR12-2 (Ghi16143), Le (Les20302), Md (Mdo2872), Mt (Mtr11875), Nt (Nta5372), Rr (Rra14385), Rs (Rsa16230), and St (Stu21353). A schematic representation of the organization of conserved domains in each of the four major groups is also indicated based on CD search analyses (http://www.ncbi.nlm.nih.gov/Structure/cdd) and GPI anchor prediction using the GPI-SOM program (http://gpi.unibe.ch). DM13, Domain potentially involved in redox reactions; Cyt b561, cytochrome b561. The F1, F2, and G groups have been defined based on cytochrome b561 phylogeny (Tsubaki et al., 2005). Asterisks indicate proteins belonging to the F1 and F2 groups, but containing a single DOMON domain without the cytochrome b561 domain. [See online article for color version of this figure.]