Researchers from MIT and the Singapore-MIT Alliance for Research and Technology (SMART) have developed sensors made from carbon nanotubes that can detect signals revealing when plants are experiencing stress such as heat, light, or attack from insects or bacteria. The sensors can detect two signaling molecules plants use to coordinate their response to stress: hydrogen peroxide and salicylic acid, which can serve as an early warning system for farmers looking to intervene before their crops are lost. The sensors produce distinctive patterns of chemical changes in plants that rise and fall in response to different types of stress.
The sensors consist of tiny carbon nanotubes wrapped in polymers that emit a fluorescent signal when the target molecule is present. By changing the three-dimensional structure of the polymers, the sensors can be tailored to detect different molecules. In this study, the researchers developed sensors that can detect salicylic acid, a molecule involved in regulating plant growth, development, and response to stress. The sensors are applied to the underside of plant leaves, and the signal can be easily detected using an infrared camera when activated.
Using pak choi plants, the researchers observed distinct responses to different types of stress, including heat, intense light, insect bites, and bacterial infection. Each type of stress led to the production of hydrogen peroxide within minutes, reaching maximum levels within an hour before returning to normal. Salicylic acid production occurred within two hours, at distinct time points for heat, light, and bacterial infection, but not for insect bites. These findings represent a communication “language” that plants use to coordinate their responses to different stresses, ultimately aiding in their survival.
The research team is now working on creating sentinel plants that can be monitored to provide farmers with early warnings when their crops are under stress. This technology offers real-time information from a wide range of plants, providing a faster intervention option than existing sensors that are plant-specific, limiting their application. The sensors can also trigger responses such as adjusting greenhouse temperature or light levels, further aiding in crop management strategies.
This breakthrough technology offers a new way to monitor plant health in real-time, allowing farmers to intervene before irreparable damage occurs to crops. By incorporating this technology into diagnostics, farmers can receive immediate information faster than any other sensor system, enabling quick interventions to protect crop health. Additionally, the researchers are continuing to develop sensors to detect other plant signaling molecules to gain more insights into plant responses to stress and other stimuli, further enhancing crop management strategies. The research was supported by the National Research Foundation of Singapore under its CREATE program through SMART and the USDA National Institute of Food and Agriculture.
