Histogram of GC content for 34 seed plant plastid genomes, including the gymnosperm Pinus and 33 angiosperms (see Table 2 for list of genomes). Taxa are arranged phylogenetically following tree in Fig. 8. A. Overall GC content of complete genomes. B. GC content for 66 protein-coding genes, including average value for all codon positions, followed by values for the 1st, 2nd, and 3rd codon positions, respectively.
Cai et al. BMC Evolutionary Biology 2006 6:77 doi:10.1186/1471-2148-6-77