Nanoscale sensing technology promising for water regulation in plants

A new technology is allowing researchers to measure the water status inside a plant leaf’s surface. This could ultimately help with water regulation, something that is crucial to plant health.

Developed by a team from Cornell University (Ithaca, NY), with the new technology, which employs nanoscale sensors and fiber optics, the researchers injected nanoparticles that are formed of a soft synthetic hydrogel to measure a maize plant leaf’s water potential; this hydrogel swells and shrinks based on water availability in a leaf. According to the researchers, the hydrogel occupies the interstitial spaces between cells in a plant’s mesophyll, where much of its photosynthesis and water stress occur.

The hydrogel contains dyes whose interactions allow it to fluoresce at different wavelengths depending on how close the dye molecules are to each other. Specifically, the hydrogel was injected “in multiple places along meters-long maize leaves and then measured the water gradients both along the length of the leaves and through the mesophyll.” With these measurements, the team developed a model of the tissue response to water stress and was able to accurately predict the dynamics observed in the field. Additionally, using fiber optics, the researchers have been able to shine a light and get a spectrum back, which “provides a measurement of water potential inside the leaf.”

The new technology will ultimately help plant biologists better understand water stress, which could in turn lead to more drought-resistant, water-efficient crops. Commercially, it shows potential for applications in research and production agriculture. Reference: P. Jain et al., Proc. Nat. Acad. Sci., 118, 23, e2008276118 (Jun. 8, 2021); doi.org/10.1073/pnas.2008276118.