Figure 1. A number of routes are being studied to improve photosynthesis in crop plants.
These include (1) improving the efficiency of the primary CO 2-fixing enzyme Rubisco, (2) optimizing elements of the Calvin-Benson cycle, (3) introducing the carboxysome-based carbon concentrating mechanism (CCM) from cyanobacteria, (4) introducing an algal pyrenoid CCM, and (5) improving the photochemical response of photosynthesis to rapid changes in light conditions. Further studies are also related to attempts to convert C 3 crops such as rice to the more efficient C 4-type photosynthesis.