Reconstruction And Comparative Analysis Of Metabolic Networks For C3and C4Plants

C4plants have50%higher photosynthetic efficiency than C3plants;we explore engineering approach of transition from C3to C4plants whichcan improve the crop yield of C3plants. To identify the possibility oftransition, the systematic comparisons of C3and C4plants metabolism arenecessary.First of all, we improved and compared the genome-scale metabolicnetworks of Arabidopsis （AraGEM） and C4plant （C4GEM）, we found theC3network exhibit more dense topology structure than C4, C4networkhas better robustness and better modularity than C3while the plants havesame basal metabolism. The C4network has also better responses of lightintensity and CO₂concentration in the environment.Secondly, we constructed the C4plants primary metabolic model（C4PMM） while some problems such as large number of redundancy anderror in constraints exist in the genome-scale networks. The proteomicsdata was integrated to C4PMM which can improve the ability of prediction.C3PMM （C3plants primary metabolic model） was also combined withtranscriptome data into constraints.Finally, the systematic comparisons were performed betweenC4PMM and C3PMM. We identified the topological differences andanalysed response mechanism under different environments in wholenetworks and different metabolic pathways. Our simulation results hadgood consistency with experimental results, so that flux balance analysis isa powerful tool to study plant evolution in the systemic level. Metabolic network construction and analysis has great significance tounderstand photosynthesis evolution mechanism. C4PMM will beimportant resource for related research of C4plant primary metabolism.