Scientists create glow-in-the-dark plants which could be used as street lights

Luminous plants bright enough to light up entire streets might sound like something from a science fiction story.

But scientists in China say this could become a reality sooner than you’d think, after creating what they say are the world’s first multi-coloured and rechargeable glow-in-the-dark succulents.

Researchers had already made plants that emit a greenish glow by transferring genes from luminous mushrooms back in 2020.

However, constrained by the plant’s natural colour, scientists could only make them produce an eerie green glow.

Now, researchers at South China Agricultural University in Guangzhou have gone one step further, using a different technique that allows the plants to shine even brighter and in a range of colours.

“Picture the world of Avatar, where glowing plants light up an entire ecosystem,” said Shuting Liu, a biologist and co-author of the study published in the journal Matter.

A green wall of glowing plants produced enough light to allow researchers to see text and images in the dark. / Credit: CNN/Shuting Liu

“We wanted to make that vision possible using materials we already work with in the lab. Imagine glowing trees replacing streetlights,” she added.

The team’s new method marks a departure from the traditional gene-editing technique that scientists use to achieve this effect, following a model pioneered by a team at the Massachusetts Institute of Technology.

Injecting a plant with nanoparticles instead of editing its genes allowed the researchers to create plants that glow red, blue and green.

Liu and her fellow researchers injected the leaves of the succulent Echeveria “Mebina” with strontium aluminate, a material often used in glow-in-the-dark toys that absorbs light and gradually releases it over time.

“We were particularly inspired by inorganic afterglow materials that can be ‘charged’ by light and then release it slowly as afterglow,” Liu told ITV News’ American partner CNN.

She said her team’s goal was to “move beyond the usual colour limits of plant luminescence” and “provide a photosynthesis-independent way for plants to store and release light – essentially, a light charged, living plant lamp”.

The research team attempted to show the practical application of their idea by constructing a green wall made of 56 plants that produced enough light to see text, images and a person located up to ten centimetres away, according to the study.

Once injected and placed under direct sunlight for a couple of minutes, the plants continued to glow for up to two hours.

While the brightness of the afterglow gradually weakened during that time period, “plants can be recharged repeatedly by exposure to sunlight,” Liu said.

This replenishes the plants’ stored energy, “allowing the plants to continue glowing after the sunlight is removed”.

The Echeveria ‘Mebina’ plants were injected with strontium aluminate, allowing them to be ‘recharged’ by sunlight. / Credit: CNN/Shuting Liu

The plants maintain the ability to emit the afterglow effect 25 days after treatment, Liu said, and older leaves injected with the afterglow particles continue to emit light under UV stimulation “even after wilting”.

While strontium aluminate can readily decompose in plants, posing harm to plant tissue, Liu said, the scientists developed a chemical coating for the material that acts as a protective barrier.

The researchers said in the paper that they see their findings as highlighting “the potential of luminescent plants as sustainable and efficient lighting systems, capable of harvesting sunlight during the day and emitting light at night”.

However, other scientists are sceptical about the real-world application of these glowing plants.

“I like the paper, it’s fun, but I think it’s a little beyond current technology, and it might be beyond what plants can bear,” said John Carr, a professor of plant sciences at the University of Cambridge.

“Because of the limited amount of energy that these plants can emit, I don’t really see them as streetlights anytime soon,” he added.

Liu acknowledged that the plants “are still far from providing functional illumination, as their luminescence intensity remains too weak for practical lighting applications”.

“Additionally, the safety assessment of afterglow particles for both plants and animals is still ongoing,” the researcher added.

She said the luminescent plants currently “can primarily serve as decorative display pieces or ornamental night lights” – but she believes their use can be expanded in the future.

“Looking ahead, if we can significantly enhance the brightness and extend the duration of luminescence – and once safety is conclusively demonstrated– we could envision gardens or public spaces being softly illuminated at night by glowing plants.”