Smith B N
Biosystems. 1976 Apr;8(1):24-32. doi: 10.1016/0303-2647(76)90004-6.
The hypothesis is presented that C4 photosynthesis has evolved at lease in part in response to reduced efficiency of C3 photosynthesis due to increased oxygen partial pressures in our recent atmosphere. Oxygen competition with carbon dioxide for the active site on ribulose diphosphate carboxylase was of little consequence when atmospheric levels of CO2 were high and those of O2 were low. However at the present low CO2 and high O2 partial pressures, adaptations for protecting the enzyme from oxygen have been selected.
C4光合作用的进化至少部分是为了应对由于近代大气中氧分压升高导致的C3光合作用效率降低。当大气中二氧化碳含量高而氧气含量低时，氧气与二氧化碳竞争核酮糖二磷酸羧化酶的活性位点影响不大。然而，在目前低二氧化碳和高氧分压的情况下，已经选择了保护该酶免受氧气影响的适应性机制。
