Researchers Design Sensors to Quickly Identify Plant Hormonal Agents

Scientists from the Disruptive and Sustainable Technologies for Agricultural Precision (DiSTAP) interdisciplinary research study team of the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research study enterprise in Singapore, and their local partners from Temasek Life Sciences Laboratory (TLL) and Nanyang Technological University (NTU) have developed the first-ever nanosensor to allow quick testing of artificial auxin plant hormones. The unique nanosensors are safer and less laborious than existing methods for testing plants’ response to substances such as herbicides. They can be transformative in improving agricultural production and our understanding of plant growth.

The researchers created sensors for two plants hormones, 1-naphthalene acetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4 D), used widely in the farming industry to regulate the plant’s growth and also as herbicides, respectively. Current methods to find NAA and 2,4-D damage the plants and are incapable of giving real-time in vivo monitoring and information.

The developed sensor can identify the existence of NAA and 2,4-D in alive plants at a fast pace, giving plant information in real-time without harming it. The sensor was developed based on the concept of corona phase molecular recognition (CoPhMoRe) spearheaded by the Strano Lab at SMART DiSTAP and MIT. The team successfully tested the sensors on various common crops such as spinach, pak choi, and rice across different planting mediums such as soil, hydroponic, and plant tissue culture.

The study can facilitate much more efficient use of synthetic auxins in agriculture and possess significant potential to advance plant biology research, as explained in a paper titled “Nanosensor Detection of Synthetic Auxins In Planta using Corona Phase Molecular Recognition” published in ACS Sensors.

“Our CoPhMoRe technique has formerly been utilized to detect compounds such as hydrogen peroxide and heavy-metal contaminants like arsenic-but this is the first successful instance of CoPhMoRe sensors developed for spotting plant phytohormones that regulate plant growth and also physiology, such as sprays to prevent premature blooming and production of fruits,” says DiSTAP co-lead principal investigator Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT. “This technology can substitute existing advanced sensing methods which are tiresome, destructive, and hazardous.”

Of both sensing units created by the research team, the 2,4 D nanosensor likewise revealed the capability to detect herbicide susceptibility, allowing farmers as well as agricultural scientists to quickly learn just how vulnerable or resistant different plants are to herbicides without the demand to observe the plant or weed growth over days. “This could be extremely beneficial in revealing the mechanism behind how 2,4 D works within plants as well as why crops grow herbicide resistance,” states DiSTAP and TLL Principal Investigator Rajani Sarojam.

” Our study can assist the industry in accumulating an improved understanding of plant growth dynamics and can potentially alter completely how the industry screens for herbicide resistance, eliminating the need to observe the crop or weed growth over days,” states Mervin Chun-Yi Ang, a research scientist at DiSTAP. “It can be applied to a wide variety of plant species and also planting mediums, and could easily be utilized in commercial setups for fast herbicide sensitivity testing, such as urban farms.”

NTU Professor Mary Chan-Park Bee Eng states, “Utilizing nanosensors for in planta detection discards the need for extensive extraction and filtration processes, which conserves money and time. They also make use of extremely low-cost electronics, which makes them easily adaptable for commercial setups.”

The team says their study can lead to the future advancement of real-time nanosensors for other dynamic plant hormones and metabolites in live plants.

The development of the nanosensor, optical detection system, and image processing algorithms for this study was done by SMART, NTU, and MIT. At the same time, TLL validated the nanosensors and supplied an understanding of plant biology and plant signaling mechanisms. The study is carried out by SMART and sustained by NRF under its Campus for Research Excellence And Technological Enterprise (CREATE) program.

Originally published on MIT NEWS. Read the original article.

Reference: Mervin Chun-Yi Ang et al, Nanosensor Detection of Synthetic Auxins In Planta using Corona Phase Molecular Recognition, ACS Sensors (2021). DOI: 10.1021/acssensors.1c01022