Scientists pioneer nanosensor to decode climate change stressors in crops

29 Apr 2024 --- Researchers have developed the first nanosensor to monitor salicylic acid (SA) in real-time during the early stages of stress response. This plant hormone is crucial for plant growth, development and stress responses to pathogens, temperature, drought, salinity, metals, UV light and osmotic stress. The team also pioneered a method to combine (or multiplex) the sensor with others for simultaneous and real-time tracking of multiple plant hormone profiles and chemical signals. 

These new insights are vital in cultivating crops that are resilient to stressors such as climate change. Traditional stress detection methods rely on time-consuming and labor-intensive lab tests, which are destructive and disruptive to plant growth. Emerging technologies focus on metabolic changes after the initial stress perception and signaling when there are limited options for reparative measures. 

The research was conducted by scientists from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) Interdisciplinary Research Group of Singapore-MIT Alliance for Research and Technology (SMART) — Massachusetts Institute of Technology’s (MIT) research enterprise in Singapore — in collaboration with Temasek Life Sciences Laboratory. 

“This sensor for SA gives us insights into a new signaling language within living plants. Now, farmers can understand in real-time the specific types of stress and stressors affecting the crops,” shared Professor Michael Strano, corresponding author, DiSTAP co-lead principal investigator and Carbon P. Dubbs professor of Chemical Engineering at MIT.

Plant stress 
The researchers published their findings in plant health monitoring in Nature Communications. The research and technology build on SMART DiSTAP’s work with innovative plant sensors. 

After developing the SA-detecting nanosensor, the researchers validated it in planta in living pak choi, Chinese cabbage. Combining the sensor with others enables earlier diagnosis and helps improve plant stress tolerance and mitigate crop losses due to environmental stress. 

“Fluctuations in SA levels serve as early indicators of plant stress,” explains Jolly Saju, research officer at Temasek Life Sciences and co-lead author of the paper. 

“By harnessing the power of plant nanobionic sensors designed specifically for detecting SA, farmers can proactively measure plant stress levels long before visible signs manifest. This invaluable data empowers farmers with the foresight needed to pre-emptively intervene and implement targeted measures to mitigate crop loss.”

Last year, researchers indicated that acute climate change impact on cereal crops, without adaptive measures, resulted in 7% to 23% of crop yield losses. Meanwhile, a harmful fungal blast disease is thriving under climate change conditions in tropical regions, which could reduce global wheat production by 13% before 2050. 

The researchers envision using multiplexed nanosensors in plants to give farmers real-time data on crop health.Sensor multiplexing 
The researchers paired the SA sensor with another designed to detect hydrogen peroxide and evaluate the power of multiplexed sensors. They found that different stressors trigger a distinct pattern in the plants’ SA and hydrogen peroxide production.

This offers a deeper understanding of how plants communicate and combat different stresses, paving the way for developing crops with enhanced resilience and, ultimately, contributing to more secure global food supplies. 

The researchers exposed plants, like pak choi, to different stressors, such as light fluctuations, extreme heat, pathogen attacks and physical plant damage to mimic insect bites, and measured the resulting pattern of SA and hydrogen peroxide in plants. 

“The ability to examine the activation and coordination of different signaling molecules simultaneously during plant stress responses will truly enhance our understanding of how plants react to stress and the mechanisms involved,” comments co-author Dr. Rajani Sarojam, senior principal investigator at Temasek Life Sciences Laboratory, and principal investigator at DiSTAP.

“The nanosensors are species-agnostic and can be used to study any commercial crop, providing new approaches to increase plant stress resilience in the face of climate change.” 

Farmer support 
SMART DiSTAP combines various sensors to create a more comprehensive overview of plant stress. Potential applications include integrating multiplexed nanosensors into specific plants within a batch of crops to turn these into “sentinels” for the entire batch. They could monitor environmental variables, pathogens and stress, giving farmers real-time data on crop health. 

“This groundbreaking technology represents a significant leap forward in plant stress detection and diagnosis,” says Dr. Mervin Chun-Yi Ang, principal research scientist at SMART DiSTAP and co-lead author of the paper. 

“By unlocking its full potential through sensor multiplexing, comprehensive data analysis and computational modeling, we envision a future where on-farm diagnostics can empower farmers to optimize crop health and resilience. This technology could revolutionize urban agriculture, fostering a more secure and sustainable global food supply.”

By Jolanda van Hal