Bioengineers have proposed a bold new method of food production that could dramatically reshape agriculture, potentially making it more efficient, sustainable, and adaptable to environments like space.

Dubbed 'electro-agriculture', this system would replace traditional photosynthesis – a process that converts only about 1% of absorbed light energy into chemical energy in plants – with a solar-powered reaction that efficiently converts carbon dioxide (CO2) into an organic molecule that plants could use as food. 

Image: Feng Jiao.

“Since electro-agriculture is not dependent on climate conditions and offers greater efficiency than traditional farming, it could serve as a valuable method for producing supplemental food when necessary,” said senior author Feng Jiao. 

“With global climate change affecting agriculture, innovative food production technologies are becoming increasingly vital to stabilise food markets and support a growing population.”

A revolution in food production

Photosynthesis, the process that enables life on Earth by converting sunlight into chemical energy in plants, is notoriously inefficient. According to researchers, only a fraction of the sunlight a plant absorbs – about 1% – is transformed into usable energy. Given the growing demand for food, the limitations of arable land, and the looming climate crisis, improving this efficiency is critical. 

In electro-agriculture, solar panels would be used to power a chemical reaction between CO2 and water, producing acetate, a molecule related to acetic acid (the main component in vinegar). Plants would be genetically engineered to use this acetate as a primary energy source instead of relying on photosynthesis.

If this system were adopted on a large scale, it could reduce the land required for agriculture by a staggering 94%, according to the researchers’ estimates.

Robert Jinkerson, a biological engineer at the University of California, Riverside, and the corresponding author of the paper, sees this technology as a major leap forward. “If we don’t need to grow plants with sunlight any more, then we can decouple agriculture from the environment and grow food in indoor, controlled environments,” he explains in the press release. 

The shift could move agriculture into vertical, multi-storey indoor farms where solar power is harnessed outside the building to drive plant growth inside.

More efficient than photosynthesis

At the heart of this innovation is the effort to improve the efficiency of the energy conversion process. Jiao notes that the current version of electro-agriculture achieves about 4% efficiency – four times higher than photosynthesis.

“Because everything is more efficient with this method, the CO2 footprint associated with the production of the food becomes much smaller,” Jiao points out, emphasising the environmental benefits.

This approach has the potential to address several of the inefficiencies that plague traditional agriculture, such as the vast amounts of water, fertiliser, and land required to grow crops.

Electro-agriculture would produce food in a controlled, indoor environment, allowing for more precise resource management and reducing farming’s environmental impact. Additionally, it could mitigate the impact of climate change by decoupling food production from weather patterns and seasonal changes. 

The science behind acetate-eating plants

To achieve this vision, the researchers are working on re-engineering plants to 'eat' acetate. Plants naturally have a metabolic pathway that allows them to break down food stored in their seeds during germination.

This pathway is deactivated once the plant starts using photosynthesis. The bioengineering team aims to reactivate this process in mature plants so they can use acetate as an energy source.

While the team’s initial research is focused on tomatoes and lettuce, they plan to expand to high-calorie staple crops like cassava, sweet potatoes, and grains. So far, they’ve engineered plants that can use acetate in combination with photosynthesis, but the ultimate goal is to create plants that rely entirely on acetate for energy, eliminating the need for light altogether. 

While plant research is still in its early stages, other organisms, such as mushrooms, yeast, and algae, already naturally use acetate as an energy source. This means the technology could be commercially applied to these food-producing organisms much sooner. 

“We have successfully produced mushrooms entirely from acetate derived from CO2. These mushrooms look and taste just like traditional mushrooms, with no noticeable differences. Other food products are still under development, but they are expected to have a similar taste to conventional options,” said Jiao.

The study has been published in Joule.