Integrating C4 photosynthesis into C3 crops to increase yield potential

The growth rate of the human population is faster than improvements in crop yields. To feed people in the future, multiple strategies are required. One proposed approach is to raise the yield potential of C-3 crops by modifying photosynthesis to the more efficient C-4 pathway. Owing to complex changes associated with C-4 photosynthesis, it is no understatement to define this conversion as one of the Grand Challenges for Biology in the 21st Century. Here we outline the challenges of installing a C-4 system and assess how new approaches and knowledge may help achieve this goal.