MIT's plants that glow like fireflies could replace electrical lighting

To create the glow, engineers used the aid of an enzyme called luciferase. The enzyme acts on a molecule called luciferin leading to the emission of lights from the leaves. The whole process was aided by the application of another molecule known as co-enzyme A to neutralise the reaction of a byproduct that affects the activity of luciferase.

They embedded the chemicals into the plant by placing the components into different carriers. Later, they placed the particles inside a solution in which the plant was immersed into. This was then exposed to high pressure which in turn allowed the particles to enter in the leaves through tiny pores called stomata.

https://www.moneycontrol.com/news/science/glow-in-the-dark-plants-developed-by-mit-engineers-2462567.html