Researchers in the US have genetically engineered a way of shortcutting photosynthesis to increase the size of tobacco plants by up to 40%.
They say the development could be applied to increase the yield of other important crops, as a way of boosting food productivity for a growing population in the face of climate change. The research was published today in the journal Science.
Estimates suggest that, compared with 2005, worldwide demands on the agricultural system will increase by 60 to 120% by the middle of the century. However, crop yields are currently only increasing by less than 2% per year, suggesting there will be a significant shortfall in meeting this demand.
Although the use of pesticides, fertilisers and mechanization have improved yields over recent decades, these approaches are limited in terms of their potential for future growth.
Now, researchers are looking at ways to manipulate the process of photosynthesis as a way of boosting yields.
In photosynthesis, the chemical steps involved in converting carbon dioxide and water into sugar produce toxins that limit a crop’s potential to grow.
The plant recycles these chemicals in a process called photorespiration, but this uses up valuable energy that could otherwise have been used to boost the plant’s growth.
Now, Dr. Paul South from the US Agricultural Research Service and colleagues have found a way around this problem by engineering a way to shortcut this energy-expensive process.
One important holdback is that the photosynthesis glitch becomes more prevalent under the conditions of higher temperature and drought.
Co-author Amanda Cavanagh says: "Our goal is to build better plants that can take the heat today and in the future, to help equip farmers with the technology they need to feed the world.”
The scientists used tobacco plants for their experiment because they are quick and easy to modify, but they hope the approach could be used to significantly boost the yield of other important crops such as wheat, rice, soybean, potato and tomato.
However, the team acknowledges that the controversy surrounding genetic engineering will mean a lengthy review process will be needed to show that crops grown using this technology will be accepted by farmers and consumers.