‘Smart plants’ could soon detect deadly radon and mold in your home

Your favorite succulent just got a little more succulent. Inspired by smoke detectors and smart home monitors, scientists are genetically engineering houseplants to sense harmful chemicals from mold and other kinds of fungi—and alert homeowners to their presence. If they can figure out how houseplants respond to other threats, such as radon and airborne pathogens, researchers could one day engineer “smart plants” to tackle a whole host of problems.

The idea has already been tested on the farm, researchers write in a review published today in Science. From 2012 to 2013, plant scientists modified tobacco plants (Nicotiana tabacum) to produce excessive amounts of orange fluorescent protein when they encountered disease-causing bacteria. To do so, researchers first identified the genes in the tobacco plant genome that were likely to react to harmful airborne chemicals known as volatile organic compounds. Then, they inserted synthetic “promoters” into the plants’ DNA to crank those reactions up to 10. When the engineered plants sensed the bacteria, their cells reacted by pumping out the orange fluorescent protein. To detect the signal, farmers simply had to put on light-filtering goggles and see whether the plants glowed orange under a green light, the researchers reported previously in Plant Biotechnology Journal.

That technology could soon move inside the home, say reviewers, where “living walls” of genetically modified plants could be installed near air vents, where they might one day be able to sense toxic mold growth and airborne viruses, like the flu. Right now, just like the tobacco plant, they would have to be illuminated to see the signal, in this case with ultraviolet light. Scientists hope to soon discover proteins in houseplants that could produce a signal visible to the naked human eye.

But before they can do that, scientists will need to analyze the DNA of several houseplant species to figure out what kinds of reactions can be manipulated—and what kinds of signals can be made. That’s because, unlike crops and many popular flowering plants, little is known about the genes of houseplants. Once researchers zero in on the genes they can manipulate, though, be on the lookout for your new, whole-house “check engine” light.

*Correction, 20 July, 9:55 a.m.: An earlier version of this story misstated the Latin name for the tobacco plant.