By combining high-performance computing and advanced genetic engineering, a team of public sector scientists has taken steps to achieving agriculture’s Holy Grail: boosting the photosynthetic efficiency of plants. Plant biologist Stephen P. Long and colleagues at the University of Illinois and the Institute for Computational Biology, Shanghai, have put a gene from cyanobacteria into plants that has boosted photosynthetic rate by 30 percent, according to a paper recently published in Cell. “We now know every step in the processes that drive photosynthesis in C3 plants such as soybeans and C4 plants such as maize.” said Long, a world-renowned expert on photosynthesis. Long notes that computer models enable the team to understand and determine where the bottlenecks in photosynthesis are, and “advances in genetic engineering will help us augment or circumvent those steps that impede efficiency.”
Photosynthetic microbes offer other clues to improving photosynthesis in plants, the researchers report in Cell. Some bacteria and algae contain pigments that utilize more of the solar spectrum than plant pigments do. If added to plants, those pigments could bolster the plants’ access to solar energy.
Meanwhile, the U of I team reports that computer analyses of the way plant leaves intercept sunlight have revealed other ways to improve photosynthesis. Many plants intercept too much light in their topmost leaves and too little in lower leaves. A team led by the University of Illinois’ Donald Ort aims to make plants’ upper leaves lighter, allowing more sunlight to penetrate to the light-starved lower leaves.
The next step is to create an in silico plant to simulate the interactions among biological scales. While many hurdles remain for the project, Long says the work should be undertaken now. In the Cell paper, Long and his team argue that improving photosynthetic efficiency offers the best hope of increasing crop yields enough to feed a planet expected to have 9.5 billion people on it by 2050.
“If we have a success today, it won’t appear in farmers’ fields for 15 years at the very earliest,” Long said. “We have to be doing today what we may need in 30 years.”
Since 1013, Long has lead RIPE (Realizing Improved Photosynthetic Efficiency for Increased Productive Potential of Food Crops), a $25-million project supported by the Bill and Melinda Gates Foundation to guide improvement of crop photosynthetic efficiency of key food crops, including rice and cassava.
For more on the paper, please read the University of Illinois’s release “Report: Photosynthetic “Hack” is Needed to Feed World by 2050.” And for more on Long, and his work to optimize photosynthetic efficiency, listen to this interview on the “People Behind the Science” podcast.