Fig. 1From: Identification and evolution of C4 photosynthetic pathway genes in plantsPhylogenetic tree established for the NADP-ME gene family in 25 species (A branch). The A branch was further diverged into subfamilies A1 and A2. For the branch model, a1-a7 were assigned to be the front branches in the selective pressure analysis. C4 plants are marked with green circlesBack to article page