Plants have always played a vital role in our lives, providing us with food, clothing, and the very air we breathe. However, researchers at South China Agricultural University are exploring a novel application of plants: aiding us in navigating our surroundings at night. In a groundbreaking study published in the journal Matter, these scientists describe their creation of glow-in-the-dark plants by injecting synthetic materials into the tissues of living succulents.
These innovative bionic botanicals can emit light in various colors and can recharge after exposure to light. While the potential for practical applications is exciting, these glowing plants are not yet ready to illuminate our homes just yet. The transformation took place at the university’s Key Laboratory for Biobased Materials and Energy, a hub for exploring the intersection of technology and plant biology.
In previous projects, researchers have worked on enhancing photosynthesis efficiency using carbon nanoparticles. However, for this specific initiative, the goal was to create “a living, light-charged plant lamp,” according to Shuting Liu, a lab affiliate and the first author of the paper. The concept of glowing plants has been a staple in science fiction and fantasy, but it has only been realized in our world since the 1980s, beginning with the splicing of firefly genes into tobacco plants at the University of California, San Diego.
More recent endeavors have resulted in commercially available glowing plants, such as glowing petunias, which are genetically modified using genes from bioluminescent bacteria and fungi. In contrast, Liu and her team opted to utilize a human-made material called strontium aluminate. This compound is commonly found in glow-in-the-dark stars that adorn bedroom ceilings. Unlike bioluminescence, which relies on continuous chemical reactions to produce light, strontium aluminate exhibits phosphorescence, absorbing energy from external light and releasing it gradually over time.
While strontium aluminate has been used in plants before, Liu aimed to achieve a brighter and longer-lasting glow by utilizing larger particles, approximately the size of a human red blood cell. This endeavor involved “continuous trial and error” as different plants were injected. Many plants, such as bok choy and pothos, experienced uneven results due to the particles becoming trapped in the plant tissue. Ultimately, Liu discovered that the rosette-shaped succulent, Echeveria Mebina, had the ideal intercellular channels to produce a uniform luminescent glow.
After exposure to light, these glowing plants exhibit a brightness comparable to that of a candle and continue to emit light for at least two hours. By experimenting with different materials to create the particles, the researchers produced a spectrum of colors, including red, orange, and multicolored variations, alongside the classic green glow.
Scott Lenaghan, director of the Center for Agricultural Synthetic Biology at the University of Tennessee, praised the aesthetic appeal of the luminescent plants, stating, “The luminescent images are beautiful, and the approach clearly works.” However, he pointed out that the current applications of this technology are somewhat limited, especially when considering the need to enhance the duration of luminescence.
Moreover, the use of synthetic materials raises questions about the ecological impact of these modified plants. While they could potentially serve as low-energy light sources, the long-term effects of the microparticles after the plant’s lifespan remains uncertain. “What happens to the microparticles once the plant dies?” Lenaghan asked, emphasizing the need for careful consideration of any man-made technologies.
Liu acknowledges that there is much work ahead, including reducing the environmental footprint of these innovations. She hopes that other researchers will collaborate to further explore this technology. “At this stage, our priority was to establish the proof of concept,” she said. Liu envisions a future where a plant night light could exist, picturing “a small succulent under a glass dome, quietly glowing on its own in the evening.” She firmly believes that this dream will become a reality.
