Regulation and Evolution of C4 Photosynthesis

C 4 photosynthesis evolved multiple times independently from ancestral C 3 photosynthesis in a broad range of flowering land plant families and in both monocots and dicots. The evolution of C 4 photosynthesis entails the recruitment of enzyme activities that are not involved in photosynthetic carbon fixation in C 3 plants to photosynthesis. This requires a different regulation of gene expression as well as a different regulation of enzyme activities in comparison to the C 3 context. Further, C 4 photosynthesis relies on a distinct leaf anatomy that differs from that of C 3 , requiring a differential regulation of leaf development in C 4 . We summarize recent progress in the understanding of C 4 -specific features in evolution and metabolic regulation in the context of C 4 photosynthesis.