“Probably not, but a guy can dream.”
That’s what I thought when I saw this paper in PLoS ONE this week outlining a “Programmable Ligand Detection System.” The research, financed in large part by the DoD & DHS, aims to “adapt plants to sense and respond to specific substances for use as environmental monitors.” Antunes et al made use of a special “de-greening circuit” wherein specially-designed proteins, specific for a particular compound (TNT in this case), activate a transcription pathway that blanches the plant’s leaves.
The system works, but is far from practical, taking 24-48 hours to produce a visible response (though, as other frequent flyers will tell you, this may actually be fast enough). That’s because whenever you’re dealing with transcription, you have to wait for mRNA and protein products to be manufactured – or if you’re turning genes off, you have to wait for their products to be degraded. The major finding, other than proof-of-concept, is that these plant-based detection systems will potentially be hundreds of times more sensitive than bomb-sniffing dogs (plus they won’t get snot on you).
Researchers ultimately hope to design plants able to detect a number of environmental particles simultaneously. In my opinion, that poses a significant challenge that may make these systems impossible to implement in the real world. There’s the possibility for cross-reactions and false alarms, especially when designing a system to detect multiple compounds. The researchers believe they can have these systems meet the sensitivity and signal speed goals within 5-7 years.
Personally, I’m all for airport security that doesn’t talk back.
Update: You can read the NYTimes review of the research here.