Cracking the Photosynthesis Code Could Help Feed the World
Scientists are modifying photosynthesis to dramatically increase crop yields and reduce global food shortages.
For many people, "GMO" is a scary word. Genetically modified organisms have been controversial for years, with a major criticism being that they do nothing to significantly increase crop yields. But new research from the University of Illinois shows otherwise.
Researchers found that by boosting the levels of three proteins involved in photosynthesis they could increase plant productivity by up to 20 percent. Stephen Long, plant biology and crop sciences professor at University of Illinois, led the study with postdoctoral researchers Katarzyna Glowacka and Johannes Kromdijik. They used tobacco plants in field trials to confirm that the efficiency of photosynthesis can be increased to produce higher yields of plants, something that many scientists once thought impossible.
Long and has team chose to use tobacco plants because they're so easily modified. That researchers are optimistic the technique will translate to a number of other food crops.
"We expect it to work for all (plants), although we cannot be sure until we will see the same yield increases in seeds. We have started to try cowpea, which is an important vegetable protein source in sub-Saharan Africa, rice and cassava," Long told Seeker.
The field trials focused on a process that plants use to shield themselves from the sun. If crop leaves are exposed to direct sunlight, they will absorb more of it than they can use, which sometimes bleaches the leaves. To avoid this, plants use a process called nonphotochemical quenching (NPQ) which releases all the excess energy as heat.
But when a leaf finds itself in the shade, from a cloud or another plant for example, the process slows down, sometimes taking up to half an hour. The shade limits the photosynthesis and the nonphotochemical quenching wastes light as heat.
Long and his team calculated that, depending on the plant, as much as 30 percent of productivity was being lost.
Krishna Niyogi, a co-author of the study and a Berkeley researcher, and Long found that increasing the level of three proteins the tobacco plant could help speed up recovery.
Field tests proved this to be true. Two of the modified plant lines tested showed 20 percent higher productivity, and the third showed a 14 percent increase, compared to the unaltered tobacco plants.
The research was funded by The Bill and Melinda Gates Foundation on the condition that any agricultural products resulting from the findings be made available to farmers in developing countries in Africa and South Asia.
Long's findings offer some good news in contrast to the grim forecast for global food security. The United Nations predicts that global crop production will need to increase by 70 percent on the land we're currently using by the year 2050 in order to feed the world population.
Another developing approach to increasing crop yields is vertical farming, which is the ability to grow crops indoors in stacked vertical structures, thereby taking up less land. But Long isn't' optimistic.
"It's extremely expensive," he said, "and while you achieve more per acre, the structure casts shadows on the surrounding land and adjacent structures, decreasing their yield. Vertical farming could have a place for high value crops in cities, but would not be a solution to the additional food projected to be needed."
Long points out that farming techniques like altering photosynthesis are important because they don't require additional land. "This is why we and others are undertaking this work to try to provide crop varieties that will deliver this extra food without moving onto more land," he said.
WATCH: Is America Facing a Farming Crisis?