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This study assessed the effects of seven combinations of maize (Zea mays) genes phosphoenolpyruvate carboxylase (pepc), pyruvate phosphate dikinase (ppdk), and NADP-malic enzyme (nadp-me), on the photosynthesis of Arabidopsis. The photosynthetic rate, carboxylation efficiency, and shoot-dry-weight of Zmpepc (PC), Zmpepc + Zmppdk (PCK), Zmpepc + Zmnadp-me (PCM), and Zmpepc + Zmppdk + Zmnadp-me (PCKM) were significantly higher than those of the control wild-type (WT), with a trends to be PCKM > PCK > PC and PCM > WT. This indicated that Zmpepc was a prerequisite for improved photosynthetic performance; Zmppdk had a positive effect on Zmpepc , and the triple gene combination had the most significant synergistic effects. PCKM significantly enhanced activity of photosystem (PS)II (K, J phase) and PSI, light energy absorption (ABS/CSm) and conversion (TRo/ABS), and electron transfer (ETo/TRo). PCKM up-regulated 18 photosynthesis-related proteins, among which, 11 were involved in light reaction resulting in improved light-energy absorption and conversion efficiency, electron transfer, activity and stability of PSII and PSI, and the ATP and NADPH production. The remaining seven proteins were involved in dark reaction. The up-regulation of these proteins in PCKM improved the coordinated operation of light and dark reaction, increasing the photosynthesis and dry weight ultimately. These results also provide a promising strategy for the genetic improvement of the photosynthetic performance of C 3 crops by inserting major C 4 photosynthetic genes. • Arabidopsis was transformed with C 4 plant genes (Zmpepc , Zmppdk and Zmnadp-me). • Joint expression of the three C 4 plant genes significantly enhanced photosynthesis. • Eighteen proteins involved in photosynthetic process were up-regulated. • The light-energy absorption, conversion and CO 2 assimilation were all improved. • The overproduction of the metabolites of C 4 process may work as signals. [ABSTRACT FROM AUTHOR]