Pair-wise comparison of Z. mays and A. thaliana memory and non-memory genes according to different functional, biological process, and cellular component groups. Heat maps follow the percentage-wise distributions of the genes (Table 2, Additional file 7) over various groups according to GO categories from the four memory classes (A) or the non-memory class (B) for Z. mays (ZM) and A. thaliana (AT). Distribution of TFs encoded by memory genes (C) and non-memory genes (D) in Z. mays and A. thaliana. Pitch-black indicates 0%, and red is a linear increase in brightness to a maximum of 60% recalculated to follow the total number of transcription factor genes in the memory or non-memory categories. The heatmap function in MATLAB® was used to generate Figure 6.