Photosynthesis – turning carbon dioxide, water, and light into oxygen and sugars – is the natural process by which plants sustain themselves. It’s what has allowed life to flourish on this earth by transforming the atmosphere into an oxygen-rich environment. Besides pumping out oxygen, these beautiful leafy organisms have also provided food for all creatures, therefore, we have a lot to thank plants for.

Climate change and a growing global population have put a strain on plant numbers and capabilities here on Earth. To tackle this issue, a group of scientists from Cornell University came up with an enzyme-based solution.

Rubisco: the most important enzyme on Earth

Rubisco is the most abundantly found protein on Earth and it has been estimated that for every person there is 5kg of it. This makes sense when you consider rubisco makes up around half of the protein in plant leaves as a key enzyme that catalyzes photosynthesis.

Novel computational techniques allowed the researchers to design a modified protein most suited to increase crop yields by making photosynthesis more efficient. “We were able to identify predicted ancestral enzymes that do have superior qualities compared to current-day enzymes,” Maureen Hanson explained, lead author of the paper.

The group was able to come to this conclusion by observing the evolutionary history of rubisco. Ancient versions of this enzyme were well adapted to work in environments with high levels of CO2, as the Earth’s atmosphere was rich in the gas 20-30 million years ago.

Rapidly rising temperatures and levels of CO2 in our current climate are creating an atmosphere closer to that of ancient times. Using an enzyme that is more suited to this environment increases its efficiency, helping produce more food for the world and decreasing the number of greenhouse gasses in the air.

The future of ancient Rubisco

In the next phase of experiments, the scientists are going to put their theory into practice by genetically modifying crops and reviewing plant yields. This biotechnology is going to first be tested on tobacco plants, before being applied to a multitude of others such as tomatoes, rice, and soybeans.

“We want to replace the genes for the existing rubisco enzyme in tobacco with these ancestral sequences using CRISPR [gene-editing] technology, and then measure how it affects the production of biomass,” Hanson said. “We certainly hope that our experiments will show that by adapting Rubisco to present-day conditions, we will have plants that will give greater yields.”

Source study: Science Advances – Improving the Efficiency of Rubisco by Resurrecting Its Ancestors in the Family Solanaceae