U.S. Military Wants to Use Plants as Spies in War—Here's How

Plants—as in vegetation—could make ideal spies, according to the U.S. military, which now has a plan to use them for exactly this purpose. That's right: Military defense is going green.

The Defense Advanced Research Projects Agency, or DARPA, is the branch of the U.S. Department of Defense tasked with developing new technology for the military. Earlier this month, DARPA published a press release outlining its vision to genetically modify plants in order to help detect danger.

Plants respond physiologically to various stimuli, such as light, chemicals, pathogens and radioactivity. DARPA wants to edit the DNA of some plants so that stimuli that represent danger can easily be read by humans. The project is called the Advanced Plant Technologies, or APT, program.

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The benefits of editing the genes of plants so they can serve as spies are multifold. The complexity of nature is hard to replicate in a lab, so it may be easier to use things that grow naturally and tailor them according to need. The gene-editing technique has already been proven to work in plants, so DARPA just needs to figure out exactly what they are going to change in the genome. They know that they want plants to display bolder physiological responses to shifts in the environment, so that the military can see what plants see: poison, radioactivity or biohazards in the air.

Take land mines as an example. If plants were to, say, change color in their presence, we could easily see where the explosive devices were and either avoid or destroy them from afar. DARPA already has hardware that can detect a plant's temperature, chemical composition and other traits from the ground, air and space. The military could potentially use that information to determine danger. They would just have to scatter the plant seeds in an area and wait for them to take root and grow.

Past gene-editing experiments with plants have resulted in vegetation that didn't live very long, however. They dedicated more of their internal resources to the genetic changes, and didn't survive well. The new program hopes to address that issue.

DARPA will hold an event for scientists who want to propose their idea for the APT program on December 12 in Arlington, Virginia, for those who want to contribute.

As the agency says in its description of the new project, "Few military requirements are as enduring as the need for timely, accurate information." And what better way to get that information than through a harmless-looking plant.