MIT Researchers Develop Bacteria to Enhance Plant Self-Defence

The development of synthetic biology circuits has taken a significant step forward, thanks to researchers at MIT. They have discovered a way to grow bacteria that can function as signal-senders, enabling plants to "sense and respond to environmental conditions such as drought or attack by pests". This breakthrough could potentially lead to the creation of plants that are more responsive to their surroundings.

Background and Research The study, published in the journal Nature Chemical Biology, outlines a novel approach to designing synthetic biology circuits. These circuits utilize individual cells to send messages, similar to a transistor in technology. Transistors rely on simple on/off mechanisms to send signals and are a fundamental component of modern digital technology. By programming individual cells to respond to specific impulses, the researchers are taking advantage of cellular communication that already occurs.

According to Christopher Voigt, the paper's senior author and head of MIT's Department of Biological Engineering, "this work shows that we can get toward more complicated functions by linking up simpler functions in individual cells". He also noted that "computationally, there's nothing that your iPhone can do that these circuits couldn't do". The researchers used a common bacterium, Pantoea agglomerans, which often grows on the surface of plants, to position cells on a petri dish in a growth medium. The cells detect certain molecules and then turn them "on" or "off", sending messages up a chain.

Potential Applications The team believes that this research could be used to make plants more responsive to environmental factors. If a factor is detected, the plant could be signalled to produce a response. The researchers hope to develop circuits that one day could coat plant leaves or roots, where they could compute to sense and respond to environmental conditions such as drought or attack by pests. Voigt emphasized that "we're not trying to replace computers, but rather put computational control into biology". He noted that while the process takes much longer than the computations done by synthetic computers, it is still effective for certain applications.

Future Developments The researchers are confident that they could create almost any kind of circuit using these building blocks. They have already developed a multi-directional path that allows for the sending of a single signal to multiple different locations. The largest of the circuits contained 24 living bacterial colonies, which can combine two inputs. With further development, this technology could have a significant impact on the field of synthetic biology and beyond. The study was funded in part by the US Defense Advanced Research Projects Agency (DARPA) and by the US Intelligence Advanced Research Projects Activity.