Figure 7.

Phylogenetic tree based on the nucleotide sequences and the alignment of expansins presented in Figure 6. The third position of each codon was excluded, because it is likely to be saturated with mutations. The tree was produced by the MEGA program using the neighbor-joining method, with Kimura two-parameter distances with the complete deletion option. Bootstrap values are given above the branches and confidence probability values are indicated below. The tree was rooted using Phleum pollen allergen (PHL P1). Accession numbers are given after the gene names. The names are given according to our current naming convention, in which the letters EXP designate expansin and the first two letters indicate the genus and species: AT for Arabidopsis, CS for cucumber (Cucumis sativus), LE for tomato (Lycopersicon esculentum), NT for tobacco (Nicotiana tabacum), OS for rice (Oryza sativa), and PS for pea (Pisum sativum). Lengths of the branches represent nucleotide distances.