Simplified representation of the C4 photosynthesis pathway showing gene expression patterns of C4 pathway-related genes in leaf. PEPC, phosphoenolpyruvate carboxylase; NADP-ME, NADP-dependent malic enzyme; NAD-MDH, NAD-dependent malate dehydrogenase; AlaAT, alanine aminotransferase; NAD-ME, NAD-dependent malic enzyme; NADP-MDH, NADP-dependent malate dehydrogenase; PEPCK, phosphoenolpyruvate carboxykinase; PPDK, pyruvate/orthophosphate dikinase; AspAT, aspartate aminotransferase. The expression levels of C4 pathway-related genes in leaf are colored according to the log2(FPKM + 0.01) values across seven periods. Red indicates candidate C4 pathway-related genes that were highly expressed in seven periods; asterisks indicate genes that were differentially expressed at different developmental stages. The number of genes in each gene family is shown for four closely related species, P. giganteum, P. purpureum, C. americanus, and S. italica.
