Out in the wild, it's often every creature for itself—even plants. Left to their own devices, most wild species of plants only create enough energy to put down roots and produce leaves and seeds. But humans wanted more.
People have now been breeding and tweaking plants for millennia—making them bug resistant and helping them grow sweeter, larger fruits and vegetables. Now, new research suggests that we may be able to get plants to work even harder, radically improving crop production in the future, reports Justin Gillis for The New York Times.
Crop sciences professor Stephen Long and his team at the University of Illinois, Urbana-Champaign, inserted the genes for three proteins involved in photosynthesis into tobacco plants, which caused them to grow 14 to 20 percent more than the non-altered plants, according to the study published recently in the journal Science.
How does this work?
When plant leaves are exposed to sunlight, they absorb some of the light energy to drive photosynthesis. But the sun produces more light than the leaf can handle. In fact, so much energy hits the leaves that it can bleach or crisp up the leaf if it is not dealt with. So plants have mechanisms that switch on in bright sunlight to dissipate that extra energy as heat, a process which is called non-photochemical quenching (NPQ).
The problem is, it can take half an hour for the NPQ to switch off if clouds or other shadows temporarily staunch the glaring rays of sunlight. Instead of ratcheting up photosynthesis and ratcheting down NPQ, the plant continues to waste lots of this energy as heat. Over the course of a day, Long and his team calculated that the slow NPQ process reduced crop productivity by 7.5 to 30 percent.
To make the plants switch off NPQ more quickly, the team transferred genes for three proteins from a plant known as thale cress to the tobacco plants—chosen for their ease of manipulation. They grew the manipulated crops and got impressive results. One strain of tobacco yield increased 13.5 percent, 19 percent in another and 20 percent in a third variety of tobacco, Gillis reports.
The researchers believe that their methods will translate to food crops with the eventual goal of improving crop yields. Much of their research was funded by the philanthropic Gates Foundation, which funds many projects with the goal of improving food production around the world, reports Gillis. There are plans to next test the concept in food crops like cowpeas, rice and cassava, which are important in food-insecure areas of Africa.
“The United Nations predicts that by 2050 we’re going to need to produce about 70 percent more food on the land we're currently using,” Long says in a press release. “My attitude is that it is very important to have these new technologies on the shelf now because it can take 20 years before such inventions can reach farmer's fields. If we don't do it now, we won't have this solution when we need it.”
Not everybody is completely convinced by the tobacco results, especially since tobacco is a leaf and does not produce seeds or grains. “How does it look in rice or corn or wheat or sugar beets?” L. Val Giddings, a senior fellow at the Information Technology and Innovation Foundation in Washington asks Gillis. “You’ve got to get it into a handful of the important crops before you can show this is real and it’s going to have a huge impact. We are not there yet.”
But there are signs that technology is positioning humanity on the edge of a Second Green Revolution, in which new types of supercharged crops—able to withstand drought, salinity and poor fertility—will bring nutrition and food security to impoverished nations around the world.
Recently, researchers sequenced the genomes of 3,000 varieties of rice, which may help them find the genes controlling pesticide resistance and increased yield. Researchers have even developed a synthetic version of photosynthesis, which may help them figure out ways to make the process more efficient in food crops and could also help take some carbon dioxide out of the atmosphere.