A mathematical model of C4 photosynthesis: The mechanism of concentrating CO2 in NADP-malic enzyme type species

摘要: A computer model comprising light reactions in PS II and I, electron-proton transport mesophyll bundle sheath chloroplasts, all enzymatic most of the known regulatory functions NADP-ME type C4 photosynthesis has been developed as a system differential budget equations for intermediate compounds. Rate-equations were designed on principles multisubstrate-multiproduct enzyme kinetics. Some 275 constants needed (ΔG0′ K m values) available from literature others (V m) estimated reported rates pool sizes. The provided good simulations sizes intermediates under varying light, CO2 O2. basic novelty is coupling NADPH production via with ATP regulation C3 cycle chloroplasts. functional range ATP/NADPH ratio chloroplasts extends 1.5 to 2.1, being energetically efficient around 2. In presence such stoichiometry, concentrating function can be explained basis two processes: (a) extra consumption starch protein synthesis leads faster import compared fixation sheath, (b) residual photorespiratory activity consumes RuBP by oxygenation, causes imported accumulate cells. As wider application, may used predicting results genetic engineering plants.