Histogram of GC content for photosynthetic and genetic system genes for 34 seed plant plastid genomes (see Table 2 for list of genomes). Taxa are arranged phylogenetically following tree in Fig. 8. GC content includes average value for all codon positions, followed by values for the 1st, 2nd, and 3rd codon positions, respectively. A. GC content for 33 photosynthetic genes. B. GC content for 22 genetic system genes.
Cai et al. BMC Evolutionary Biology 2006 6:77 doi:10.1186/1471-2148-6-77