Can improving photosynthesis be the answer to the world's food shortages?

Can improving photosynthesis be the answer to the world's food shortages?

Improving Photosynthesis
ShutterstockHUANSHENG XU
Scientists at the University of Illinois have discovered that crops can increase their yields by changing their process of photosynthesis. 

Supercomputers and genetic engineering could help boost crops’ ability to convert sunlight into energy and tackle looming food shortages, according to a team of researchers.

Photosynthesis is far from its theoretical maximum efficiency, said the authors of a paper in Cell, published March 26. They say that supercomputing advances could allow scientists to model every stage in the process and identify bottlenecks in improving plant growth. 

But the authors added that far more science spending is needed to increase yields through these sophisticated genetic manipulations, which include refining the photosynthesis process.

“Anything we discover in the lab now won’t be in a farmer’s field for 20 to 30 years,” said lead author Stephen Long, a plant biologist at the University of Illinois at Urbana-Champaign (UIUC). “If we discover we have a crisis then, it’s already too late.”

The paper stated that by 2050, the world is predicted to require 85 percent more staple food crops than were produced in 2013. It warned that yield gains from last century’s Green Revolution are stagnating as traditional approaches to genetic improvement reach biological limits. 

Instead, the group said crops such as rice and wheat, which evolved the more common C3 method of photosynthesis, could be upgraded to the more efficient C4 process found in crops such as maize, sorghum and sugar cane.

Another way to improve photosynthesis would be to widen the spectrum of light crop plants can process, the scientists said. Some algae and bacteria are able to process near infrared light and this capability feasibly could be genetically engineered in crops.

Long’s lab has demonstrated in a soon-to-be-published paper that inserting genes from cyanobacteria, a type of photosynthetic bacteria, into crop plants can make photosynthesis 30 percent more efficient. A project backed by the philanthropic Bill & Melinda Gates Foundation is attempting to convert rice from C3 to C4

The paper identifies two steps necessary to achieve these gains. First, techniques that allow researchers to insert genes into targeted parts of the genome must be translated from microbe biotechnology into plant biotechnology. Second, existing partial computer models of crop plants must be combined into a complete simulation.

Genetic improvements also will have to work alongside improved farming practices, the authors said. Long said that only half of the yield gains from the Green Revolution were the result of improving crops’ genetic potential.

“Another large chunk was getting the agronomy right for those genetic improvements,” said Long.

Evan DeLucia, a plant biologist at UIUC who is not linked with the paper, said the work is promising, but with developing countries likely to be most affected by future food shortages, access to the technology is a concern.

“The work they’re doing is not possible without incredible investment,” said DeLucia. “How that translates to a farmer in sub-Saharan Africa is a very open question.”

Boosting photosynthetic rates also will add pressure on water resources already threatened by global warming, DeLucia added, as the process requires water. “Soon you will hit a water ceiling where the amount of water becomes limiting,” said DeLucia.

Long accepted the approach is unlikely to solve geographical disparities in food production. But he maintained that maximizing yields in areas where water access is not a problem should still help mitigate global food shortages.  

This article originally appeared in SciDevNet.