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 C3 crops by modifying photosynthesis to the more efficient C4 pathway. Owing to complex changes associated with C4 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 C4 system and assess how new approaches and knowledge may help achieve this goal.

► Crop yields must increase by 50% by 2030 to meet projected demands for food. ► Crop yield potential can be increased by 50% by raising photosynthetic capacity. ► Photosynthetic capacity could be increased by converting crops from C3 to C4. ► Integration of C4 photosynthesis into C3 crops is an enormous challenge. ► Opportunities exist to overcome these challenges.