Glowing cacti

A team of Chinese scientists has developed a method for creating succulents that glow in the dark, offering a potential sustainable alternative to traditional lighting. Unlike previous genetic engineering attempts that introduced genes from bioluminescent organisms (such as fireflies or bacteria) into plants, this new approach relies on a completely different technique. The researchers at South China Agricultural University did not modify the plants’ DNA; instead, they injected a solution of phosphorescent particles into their leaves. These particles, similar to those used in glow-in-the-dark toys, have a special property: they absorb light (from the sun or LED lamps) and then release it slowly over time. The team had to solve a crucial problem: the particles needed to be small enough to travel through plant tissues, but large enough to emit visible light. After several tests, they found the ideal size—comparable to that of a human red blood cell. Why succulents? The success of this experiment was mainly due to a fortunate choice: succulent plants. Scientists injected the particles into different plants, including pothos and Swiss chard, but only succulents produced a strong and uniform luminescence. The reason lies in their particular microstructure. Succulent leaves contain narrow, evenly distributed internal channels, which allowed the particles to spread within seconds, lighting up the entire leaf evenly. By contrast, other plants, with a more “airy” structure, could not distribute the particles effectively. After just a few minutes of exposure to light, these succulents were able to glow for up to two hours, in different colours including green, red and blue, depending on the type of phosphor used.

This innovation goes far beyond aesthetics. Researchers demonstrated the potential of the technology by creating a living wall with 56 glowing plants, emitting enough light to illuminate nearby objects and even allow reading. With production costs as low as less than €2 per plant, this technique paves the way to a series of practical and sustainable applications:

• Urban lighting: imagine avenues and parks lit by luminescent trees, reducing the need for energy-consuming street lamps.
• Sustainable architecture: glowing plant walls could become a design element for interiors, reducing the demand for artificial light in buildings and homes.
• Interior design: providing an ecological and enchanting alternative to traditional lamps for creating a relaxing and unique atmosphere.

Scientists are still studying the long-term safety of the particles for plant health and seeking ways to extend the duration of the glow. Nevertheless, this study represents a fundamental step towards a future where biology and sustainability converge, offering a source of light that is not only low-cost but also entirely natural and captivating.