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Image credit: Seon-Yeong Kwak

Reading by the light of your plant

Elke Bunge
14 December 2017 | updated 15 December 2017

MIT researchers have engineered a plant that glows so brightly in the dark you can read a book next to it. By embedding nanoparticles into the plant leaves, their technology could one day replace desk lamps or even turn trees into self-powered streetlights.

Trees that replace streetlights or offices illuminated by plants – it sounds like something out of a science fiction novel. In such a utopian world, houseplants would no longer be mere decoration but rather a part of the necessary furnishings. Tree-lined avenues would have value not only for their beauty but also their utility as they illuminate the street and pedestrian path at night.

To make such a vision a reality, a team led by Michael Strano, a professor of chemical engineering at MIT, is pushing the boundaries of plant nanobionics. This new field of research, which is being pioneered in Strano’s lab, aims to give plants novel features by embedding them with different types of nanoparticles.

Copying fireflies

“The vision is to make a plant that will function as a desk lamp – a lamp that you don’t have to plug in. The light is ultimately powered by the energy metabolism of the plant itself,” said Strano.

To create their glowing plants, the MIT team implanted luciferase – the same enzyme that gives fireflies their glow – into the leaves of a watercress plant.

Luciferase acts on a molecule called luciferin, causing it to emit light. Another molecule called co-enzyme A helps the process along by removing a reaction by-product that can inhibit luciferase activity.

As with a desk lamp or streetlight, the system consists of a biological light bulb (the luciferin), an on-switch (the luciferase) and an off-switch (co-enzyme A). The researchers then packaged each of these three components into a different type of nanoparticle carrier to introduce them into the plant.  

Their research results have now been published in the latest issue of the journal Nano Letters.

Ideal substitute for lighting

The MIT researchers succeeded in inducing the plants to give off dim light for nearly four hours, bright enough to read a book by. At the start of the project the plants could only glow for about 45 minutes.

The researchers are confident that they can boost both the light emitted and the duration of the light even further. This would make their technology an ideal substitute for lighting, which accounts for around 20 per cent of worldwide energy consumption.

“Plants self-repair, they have their own energy, and they are already adapted to the outdoor environment,” said Strano.

Nanobionics have great potential

The field of plant nanobionics has set itself the task of creating new capabilities for plants by means of nanoparticles. 

Just recently the research group created sensors that can be printed onto plant leaves and which send out an electronic SOS to warn when the plants are short of water. This technology could be developed for use on crops to notify farmers when the harvest is in jeopardy.

“It could have big implications for farming, especially with climate change, where you will have water shortages and changes in environmental temperatures,” said Volodymyr Koman, an MIT postdoc in Strano’s lab.