Corrected photochemical reflectance index (PRI) is an effective tool for detecting environmental stresses in agricultural crops under light conditions

• Published in: Journal of plant research Vol. 134; no. 4; pp. 683 - 694
• Main Authors: Kohzuma, Kaori, Tamaki, Maro, Hikosaka, Kouki
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.07.2021; Springer Nature B.V
• Subjects: Agricultural equipment; Agricultural production; Agriculture; Biomedical and Life Sciences; Chlorophyll; Corn; Crop yield; Crops; Drought; Environmental indicators; Environmental stress; Fluorescence; Gas exchange; JPR Symposium; Leaves; Life Sciences; Light; Photochemicals; Photosynthesis; Plant Biochemistry; Plant Ecology; Plant Physiology; Plant Sciences; Plant stress; Recovery; Reflectance; Remote monitoring; Remote sensing; Vegetation; Water melons; Xanthophylls; Zea mays; Leaf reflectance; Photosynthesis; Xanthophyll cycle; Photochemical reflectance index; Environmental stress
• ISSN: 0918-9440; 1618-0860
• DOI: 10.1007/s10265-021-01316-1

High-throughput detection of plant environmental stresses is required for minimizing the reduction in crop yield. Environmental stresses in plants have primarily been validated by the measurements of photosynthesis with gas exchange and chlorophyll fluorescence, which involve complicated procedures. Remote sensing technologies that monitor leaf reflectance in intact plants enable real-time visualization of plant responses to environmental fluctuations. The photochemical reflectance index (PRI), one of the vegetation indices of spectral leaf reflectance, is related to changes in xanthophyll pigment composition. Xanthophyll dynamics are strongly correlated with plant stress because they contribute to the thermal dissipation of excess energy. However, an accurate assessment of plant stress based on PRI requires correction by baseline PRI (PRI o ) in the dark, which is difficult to obtain in the field. In this study, we propose a method to correct the PRI using NPQ T , which can be measured under light. By this method, we evaluated responses of excess light energy stress under drought in wild watermelon ( Citrullus lanatus L.), a xerophyte. Demonstration on the farm, the stress behaviors were observed in maize ( Zea mays L.). Furthermore, the stress status of plants and their recovery following re-watering were captured as visual information. These results suggest that the PRI is an excellent indicator of environmental stress and recovery in plants and could be used as a high-throughput stress detection tool in agriculture.