Evolutionary profile of XTH in green plants. Phylogenetic tree showing XTH PoGOs in green plants. The topology was obtained by Neighbor-Joining method with genetic distances calculated by p-distance. The bootstrap values higher than 50% are shown for 1000 replicates along with Maximum-likelihood (ML) aLRT values higher than 0.50 (in the figure [NJ/ML]). Each triangle represents a PoGO and the amount of sequences belonging to each PoGO is proportional to triangles' size. The number of genes by species is given (At - Arabidopsis thaliana, Gm - Glycine max, Pt - Populus trichocarpa, Vv - Vitis vinifera, Os - Oryza sativa, Sb - Sorghum bicolor, Sm - Selaginella moellendorffii, Pp - Physcomitrella patens patens, Ot - Ostreococcus tauri, Ol - Ostreococcus lucimarinus, Vc - Volvox carteri, Cr - Chalmydomonas reinhardtii). Outgroup is formed by fungus sequences. Accession numbers for all genes in the tree are described in Additional File 3 and the detailed tree is shown in Additional File 2. * - No genes found within a PoGO that lacks genomic information, only ESTs. ( ) - Given number of different species within a PoGO.