The aim of the C4 Rice Consortium is to add features of C4 photosynthesis to the C3 plant, rice (Oryza sativa). Therefore, it is essential to know whether rice can support the expected increase in metabolite flux between the leaf mesophyll (M) and bundle sheath (BS) cells after all the C4 biochemistry has been installed. The main pathway for metabolite flux is symplastic, i.e. via the plasmodesmata (PD) connecting M and BS cells. This work aims to compare the symplastic transport mechanisms between the C3 monocot crop, rice, and the C4 plant, Setaria viridis, by looking at the PD density and pit field distribution between the M and BS cells. Electron microscopy and 3D immunolocalisation show that Setaria (C4) has higher PD density and higher pit field area coverage on M/BS cell interface than rice (C3). Ongoing fluorescent dye feeding work aims to establish if this difference is reflected in transport rate.