Improved Photosynthesis: Can It Help to Cope with Population Increase and Climate Change?.

A major determinant of yield potential in plants is the efficiency with which incident light energy is used by leaf photosynthesis to fix CO₂ into carbohydrates and biomass. Research into photosynthetic processes over the past four decades has identified limitations to the inherent efficiency of the light conversion process and has suggested specific opportunities for taking genetic strategies which have the potential to improve the photosynthetic process and raise the ceiling of yield potential under various environmental conditions. If the photosynthetic process can be enhanced then solutions can be provided for increasing food production to meet the demands of future world food security and to make crops better adapted to future climate change scenarios.

 Areas which can be targeted to improve the photosynthetic process include:

1. Improving the nature of light harvesting and its interconversion to chemical energy.
2. Changing the efficiency with which light energy is used by CO₂ fixation and carbohydrate production processes.
3. Changing the responsiveness of crops to increasing atmospheric CO₂ , which provides the potential in C₃ plants to improve CO₂ fixation and water-use efficiency
4. Changing the relationship between photosynthesis and stomatal conductance, thus altering water use efficiency.
5. Identifying natural variation which has led to the development of improved photosynthetic traits.

 The specific opportunities which have been identified for achieving gains in the above areas will be discussed in relation to the expected gains, progress made and prospects for the future of improved photosynthesis providing a pathway to a new yield revolution and enhanced adaptation to increased CO₂, temperatures and water deficits.