C4 plants are more efficient in carbon dioxide concentration that results in increased efficiency in water and nitrogen use and improved adaptation to hotter and dryer environments.
In nature, this has occurred more than 50 times in a wide range of flowering plants, indicating that, despite being complex, it is a relatively easy pathway to evolve.
Kranz (C4) anatomy arose before the C4 biochemistry within the bundle sheath cell, in response to photorespiration. Therefore, strategies to engineer C4 photosynthesis should first address the introduction of Kranz anatomy into C3 plants.