Phytosensors: harnessing plants to understand the world around us

Although plants are sessile, their ubiquitous distribution, ability to harness energy from the sun, and ability to sense above and belowground signals make them ideal candidates for biosensor development. Synthetic biology has allowed scientists to reimagine biosensors as engineered devices that are focused on accomplishing novel tasks. As such, a new wave of plant-based sensors, phytosensors, are being engineered as multi-component sense-and-report devices that can alert human operators to a variety of hazards. While phytosensors are intrinsically tied to agriculture, a new generation of phytosensors has been envisioned to function in the built environment and even in austere environments, such as space. In this review, we will explore the current state of the art with regard to phytosensor engineering.