Fig. 4
From: Analysis of codon usage bias of WRKY transcription factors in Helianthus annuus
Analysis of PR2-plot in HaWRKY genome. The mean value of A3/(A3 + T3) is 0.4678, and that of G3/(G3 + C3) is 0.5033. The curves show the center line on 0.5. Note: A3/(A3 + T3), the ratio of A against A + T at the third position of codons; G3/(G3 + C3), the ratio of G against G + C at the third position of codons