Japanese researchers have developed a portable optical scanner that can non-invasively measure environmental stress-induced changes in plants’ internal structures, offering a breakthrough tool for timely detection of pollution damage and improved crop management.
An international team led by Associate Professor Tatsuo Shiina and Dr. Hayate Goto from Chiba University’s Graduate School of Science and Engineering developed the optical coherence tomography scanner device that enables non-invasive, non-destructive evaluation of internal plant structures. Their work was published in Scientific Reports on October 31, 2025.
The research team included Assistant Professor Jumar Cadondon from the University of the Philippines Visayas and Professor Maria Cecilia Galvez and Professor Edgar Vallar from De La Salle University Manila. According to Dr. Shiina, “By using OCT, the internal structure can be non-destructively quantified layer by layer.”
Environmental pollutants such as ozone can damage the internal structure of plants and impair their growth and productivity. Conventional assessments requiring sample processing may not accurately reflect internal damage, while methods like visual inspections and microscopic examinations require invasive analysis.
The researchers performed OCT measurements on white clover leaves, an indicator plant highly sensitive to environmental pollutants. At high concentrations, ozone enters leaves through their stomata and destroys the palisade tissue, thereby changing its optical properties. The team exposed potted indicator plants to high ozone concentrations and monitored temporal changes in the same leaves over 14 days.
Experiments revealed that ozone exposure attenuated light scattering within the palisade layer, indicating structural disruption and damage to cell walls and intercellular boundaries. The researchers noted a gradual increase in palisade tissue thickness consistent with the observed decrease in OCT signal intensity and ozone-induced structural damage.
The researchers then sampled indicator plants from four different regions in Chiba Prefecture, Japan, with varying ozone concentrations ranging from 0.04 to 0.16 parts per million. They noted a similar trend in the OCT parameters of the sampled leaves, suggesting that internal structural characteristics of leaves reflect the level of ozone exposure.
The findings demonstrate the feasibility of OCT in evaluating environmental stress in plants, especially at the cellular level prior to the onset of symptoms. OCT scanning offers a non-invasive, faster and simpler alternative to conventional methods that require chemical fixation and staining, allowing evaluation of the same living leaves over longer periods.
Timely assessments with portable OCT scanning can improve disease monitoring and facilitate early detection of deficiencies or stress-induced changes, allowing early intervention to minimize losses. The technique can aid better plant management and improve crop productivity as pollution and contamination of water and soil emerge as serious threats to plant growth.
Dr. Shiina noted that continued research could expand OCT’s utility in optimizing crop environments and improving agricultural productivity. The ability to estimate atmospheric and soil conditions on-site from a single OCT measurement provides a promising approach to advancing crop management and environmental monitoring.
Additional studies can help validate the technology’s effectiveness in different environmental conditions including varying humidity, temperature and light intensities. Ozone concentrations are particularly high in urban and industrial regions and have been reported to inhibit plant growth and reduce crop yields.
The research was funded by Japan Science and Technology Agency under the program for the establishment of university fellowships towards the creation of science technology innovation.
