The role of chloroplast movement in C4 photosynthesis: A theoretical analysis using a 3-D reaction-diffusion model for maize

Chloroplast movement within mesophyll (M) cells in C4 plants is hypothesized to enhance the CO2 concentrating mechanism (CCM), but this is difficult to verify experimentally. A three-dimensional (3-D) leaf model can help analyze how chloroplast movement influences the operation of CCM. The first volumetric reaction-diffusion model of C4 photosynthesis that incorporates: detailed 3-D leaf anatomy, light propagation, ATP and NADPH production and CO2, O2 and bicarbonate concentration driven by diffusional and assimilation/emission processes, was developed and implemented for maize leaves to simulate various chloroplast movement scenarios within M cells: the movement of all M chloroplasts towards bundle-sheath (BS) cells (aggregative movement) and movement of only those of interveinal M cells towards BS cells (avoidance movement). Light absorbed by bundle-sheath (BS) chloroplasts relative to M chloroplasts increased in both cases. Avoidance movement decreased light absorption by M chloropla..., , The program is written in Matlab R2017b (The MathWorks, USA). It requires Matlab 2011 or newer versions to run the program.