Scientists Hack Photosynthesis to Boost Crop Growth

Scientists say that they have been able to fix a ‘flaw’ in photosynthesis and as a result have boosted plant productivity by an impressive 40 percent. This discovery might sound academic, but it could be a great help to our future food security.

Photosynthesis is an incredible process. It allows plants to use a complex set of chemical reactions to turn energy from sunlight into fuel they can use to grow and develop. That photosynthesis developed at all is a remarkable natural phenomena, and it provides the backbone to human and other animal existence on planet Earth. Without it there would be no vegetation to produce the abundance of oxygen and plant matter we need to survive.

As with many examples of evolution, though, photosynthesis is not a perfect system. During its inexorable forward momentum, evolution sometimes resorts to “workarounds”, for example the misplaced laryngeal nerve in the giraffe. Photosynthesis has a few quirks which, if someone designed it, we would say are flaws.

One such problem comes with a step in photosynthesis known as photorespiration. This hinges on the protein Rubisco, which has a key job during photosynthesis. It grabs carbon dioxide from the air, so that the plant can use that carbon to create sugar molecules. But it turns out that Rubisco isn’t as good at this job as we might have hoped.

A good portion of the time—about 20 percent—Rubisco will grab oxygen instead, and this is a major headache for the plant. The oxygen leads to the formation of toxic compounds that the plant must get rid of. Fortunately, plants do have a way of coping with this via photorespiration. Through a series of transportation and chemical steps they can nix the danger, but all this comes at a real cost: it requires a significant amount of energy to deal with Rubisco’s messiness.

So, scientists thought: is it possible to correct Rubisco’s mistakes? Well there is some evidence in nature that this process can be handled differently. Sugar cane, for example, has an extra step in its process, known as C4 photosynthesis, which reduces interference from oxygen. As a result, the plant has more energy to devote to growth, which in turn usually leads to larger yields.

Can We Fix Photosynthesis to Improve Plant Yields?

Researchers at the University of Illinois embarked upon the Realizing Increased Photosynthetic Efficiency (RIPE) project, utilizing the easy-to-work-with tobacco plant as part of their trials. The aim was to see if they could genetically modify the plant to correct this so-called flaw.

To test this, the team inserted new genes into the plant which effectively shut down the process of detoxification and instead established a new way for the plant to handle oxidation that takes far fewer of the plants resources. In effect, they gave the plant a blueprint for better productivity—and, according to the paper appearing this month in the journal “Science“,  it worked.

The plants performed much better than their non-engineered counterparts in both greenhouse and open-air field tests. Some even grew up to 40 percent bigger. Plant-by-plant that might not seem like a massive boost, but in terms of a whole crop that could be a significant improvement in crop yield.

The researchers are now looking at testing this with plants that are considered food staples which suffer from the Rubisco problem, including soybeans and plants like cowpeas, which are a staple food crop in many impoverished sub-Saharan African nations.

What This Means in Real-World Terms

Professor Donald Ort from the University of Illinois told the Independent that we could feed an additional 200 million people by recouping the lost calories from photorespiration through this process. ”Reclaiming even a portion of these calories across the world would go a long way to meeting the 21st century’s rapidly expanding food demands – driven by population growth and more affluent high-calorie diets,” he adds.

This research is even more important because science shows us that, as the planet warms, climate change is putting new pressures on plants and the process of photosynthesis itself. Indeed, photosynthesis needs extra steps in warmer climates, and some of our major crops do not yet have that capacity, meaning their yields will suffer.

The research also supplements other studies which have shown that genetically modifying plants to take advantage of Rubisco’s key part in the energy production process is not only more widely possible, it may be one of the solutions to ensuring the world does not go hungry.

Of course, there is still more work to do. For this research in particular, the team must now find out whether the increase in plant growth actually translates to a better yield of beans or peas or whatever else a farmer might want to grow or just makes the plants stems more robust and leaves more abundant. The latter may be good for the plant, but it’s not really good for us.

For now, though, this research offers a tantalizing glimpse into how we might improve food security in the face of climate change.

Related at Care2

Photo credit: Getty Images.

81 comments

Anna R
Anna R11 days ago

Thank you

SEND
Shae Lee
Shae Lee19 days ago

Thank you for sharing.

SEND
Richard B
Richard B20 days ago

thank you for posting

SEND
Jan S
Jan S22 days ago

Thank you

SEND
Peggy B
Peggy B22 days ago

Noted

SEND
Janis K
Janis K22 days ago

Thanks for sharing.

SEND
Vincent T
Vincent T24 days ago

thank you for sharing

SEND
Hannah A
Hannah A26 days ago

tyfs

SEND
Ingrid A
Past Member 29 days ago

Thank you

SEND
Daniel N
Past Member about a month ago

thank you for posting

SEND