DARPA Develops Plants That Could 'Sniff' Out Bio-Weapons
When one thinks of traditional surveillance tools, images of earpieces and stealthy video cameras come to mind. However, the US Defense Advanced Research Projects Agency (aka DARPA) is wanting to take a seemingly nondescript household item and use it for surveillance purposes: plants.
Advanced Plant Technologies
DARPA is developing a project known as the Advanced Plant Technologies program. Engineers once tasked with using traditional gadgets to gather intelligence will now be working with botanists. The biggest feature of the project is using these plants in order to monitor environments, using rigged plants as early warning signs of potential biochemical hazards and weapons. Effectively, the plants would be used as a canary in a coal mine.
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“Plants are highly attuned to their environments and naturally manifest physiological responses to basic stimuli such as light and temperature, but also in some cases to touch, chemicals, pests, and pathogens,” said Blake Bextine, the DARPA Program Manager for APT. “Emerging molecular and modeling techniques may make it possible to reprogram these detection and reporting capabilities for a wide range of stimuli, which would not only open up new intelligence streams, but also reduce the personnel risks and costs associated with traditional sensors.”
DARPA APT researchers won't be creating entirely new plants. They'll just be modifying a few traits to give plants new abilities and possibly enhance their natural stimuli.
The potential uses are widespread, as DARPA noted in its press release. There could be plants developed to "sniff" out explosives -- potentially changing color or wilting should certain chemicals be in the air. They could be used as surveillance to tip off military forces while walking through forested areas. While they won't be as impressive as the Ents from Lord of the Rings, these plants would certainly be able to be an extension of the US military's "eyes and ears" in potentially hazardous situations.
The first steps of the program are being completed in DARPA labs and their corresponding greenhouse facilities. The testing will take place in simulated natural environments. If everything goes as planned, DARPA noted, then the plants would be monitored for real-world use by the U.S. Department of Agriculture's Animal and Plant Health Inspection Service to ensure that they're safe for potential public use.

“Advanced Plant Technologies is a synthetic biology program at heart, and as with DARPA’s other work in that space, our goal is to develop an efficient, iterative system for designing, building, and testing models so that we end up with a readily adaptable platform capability that can be applied to a wide range of scenarios,” said Bextine.
While the project is heavily botany-based, other engineering fields within DARPA are collaborating on the APT project. DARPA is developing corresponding tools to measure the plants' temperatures, their chemical compositions, and body plan from a far distance if remote monitoring is ever a necessity.
Bioweaponry and biochemical weapons have an interesting history when it comes to its on again/off again regulation. The weapons were initially banned from usage after WWI, then used in WWII, and then banned again from 1972 to 1993. Today, biochemical weaponry is strictly monitored, but those restraints might be ignored or eroded given the biotechnological advances in recent years. Clearly, DARPA is erring on the side of caution.