Plant biologists have bumped up crop productivity by as much as 20 percent by increasing the amount of light plants use in photosynthesis, a finding that could be used to help address the world’s future food needs.
In a recent study, researchers used a rapid screening technique that genetically engineers plants–in real time–to investigate how to help plants realize their full potential during this process.
Scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), the University of California, Berkeley (UC Berkeley), and the University of Illinois targeted three genes involved in a process plants use to protect themselves from damage when they get more light than they can safely use. By increasing the expression of those genes, the scientists saw increases of 14-20 percent in the productivity of modified tobacco plants in field experiments.
Tobacco was used as the model crop plant in this study because it is easy to work with.
In photosynthesis, plants use the energy in sunlight to take up carbon dioxide from the atmosphere and convert it into biomass, which we use for food, fuel, and fiber. When there is too much sunlight, the photosynthetic machinery in chloroplasts can be damaged, so plants need photoprotection. Inside chloroplasts, plants have a system called NPQ, or nonphotochemical quenching, for this purpose.
The highly variable levels of light plants receive, particularly in densely planted crop fields, presents a challenge to the efficient use of solar energy. Plants must adapt to intermittent shading from leaves that are higher in the canopy or from passing clouds.
Half of crop photosynthesis occurs in the shade, so any improvement in speeding up recovery from photoprotection could have a big benefit, the researchers said.
The work to boost crop productivity comes as concerns about food shortages rise with the world’s population. The Food and Agriculture Organization of the United Nations estimates that food production will need to nearly double by 2050 to meet increasing demand. Yields of the world’s major staple crops have not been increasing fast enough to meet this projected need.