By embedding specialized nanoparticles
into the leaves of watercress plants,
MIT engineers have been able to induce the plants to give off
a dim light for nearly 4 hours.
And they believe that with further optimization,
such plants will one day be bright enough
to illuminate an entire workspace.
Imagine that instead of switching
on a lamp when it gets dark, you could
read by the light of a glowing plant on your desk.
To create their glowing plants, the MIT team
turned to luciferase, the enzyme that
gives fireflies their glow.
Luciferase acts on a molecule called luciferin,
causing it to emit light.
Another molecule, called coenzyme A,
helps the process along by removing
a reaction byproduct that can inhibit luciferase activity.
The MIT team packaged each of these three components
into nanoparticle carriers of varying size
to help each component get to the right part of the plant.
To get the particles into the plant leaves,
the researchers first suspended the particles into a solution.
Then plants were immersed in the solution
and exposed to high pressure, allowing
the particles to enter the leaves through tiny pores
Once in the leaves, the particles gradually
release luciferin, which then enters the plant cells, where
the luciferase performs the chemical reaction that
makes luciferin glow.
Previous efforts to create light-emitting plants
have relied on genetically engineering plants
to express the gene for luciferase.
But this is a laborious process that
yields extremely dim light and often limited
to one type of plant.
The new method, developed at MIT,
could be used on any type of plant.
So far, they have demonstrated it with arugula, kale, spinach,
In the future, the researchers say
this technology could be used to provide
low-intensity indoor lighting or transform trees
into self-powered streetlights.