The C 4 Ppc promoters of many C 4 grass species share a common regulatory mechanism for gene expression in the mesophyll cell

Summary C 4 photosynthetic plants have evolved from C 3 ancestors and are characterized by differential expression of several hundred genes. Strict compartmentalization of key C 4 enzymes either to mesophyll (M) or bundle sheath cells is considered a crucial step towards the evolution of C 4 photosynthesis. In this study, we demonstrate that the 5′‐flanking sequences of the C 4 type phospho enol pyruvate carboxylase ( Ppc ) gene from three C 4 grass species could drive M‐cell‐specific expression of a reporter gene in rice. In addition to that, we identified about 450 bp (upstream of their transcription start site) of the analyzed C 4 Ppc promoters contain all the essential regulatory elements for driving M‐cell‐specific expression in rice leaves. Importantly, four motifs of conserved nucleotide sequences ( CNSs ) were also determined, which are essential for the activity of the promoter. A putative interaction between the CNS s and an unknown upstream element(s) is required for driving M‐cell‐specific expression. This work identifies the evolutionary conservation of C 4 Ppc regulatory mechanisms of multiple closely related C 4 grass species.