Location: Plant Physiology and Genetics ResearchTitle: Chlorophyll fluorescence imaging captures photochemical efficiency of grain sorghum (Sorghum bicolor) in a field setting
|MOCKLER, TODD - Danforth Plant Science Center|
|PAULI, WILLIAM - University Of Arizona|
Submitted to: Plant Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2020
Publication Date: 8/10/2020
Publication URL: https://handle.nal.usda.gov/10113/7070008
Citation: Herritt, M.T., Mockler, T.C., Pauli, W.D., Thompson, A.L. 2020. Chlorophyll fluorescence imaging captures photochemical efficiency of grain sorghum (Sorghum bicolor) in a field setting. Plant Methods. 16. Article 109. https://doi.org/10.1186/s13007-020-00650-0.
Interpretive Summary: The fluorescence imaging system integrated with the TERRA-REF field scanalyzer can provide high-throughput fluorescence data from field grown crops. The deployment of a fluorescence imaging system in a field setting is novel and requires validation. An experiment was conducted to verify the system by comparing data collected from the imaging system and a hand held fluorometer on leaves treated with an herbicide that inhibits photosystem II. This study found that the imaging system was highly correlated with the hand held fluorometer and was able to track the decrease in photochemical efficiency due to the herbicide over a seven-day period. With the validation of the fluorescence imaging system, physiological and genetic studies can be undertaken that leverage the fluorescence imaging capabilities and throughput of the field scanalyzer.
Technical Abstract: Photosynthesis is one of the most important biological reactions and forms the basis of crop productivity and yield on which a growing global population relies. However, to develop improved plant cultivars that are capable of increased productivity, methods that can accurately and quickly quantify photosynthetic efficiency in large numbers of genotypes under field conditions are needed. Chlorophyll fluorescence imaging is a rapid, non-destructive measurement that can provide insight into the efficiency of the light-dependent reactions of photosynthesis. To test and validate a field-deployed fluorescence imaging system on the TERRA-REF field scanalyzer, leaves of potted sorghum plants were treated with a photosystem II inhibitor, DCMU, to reduce photochemical efficiency (FV/FM). The ability of the fluorescence imaging system to detect changes in fluorescence was determined by comparing the image-derived values with a handheld fluorometer. This study demonstrated that the imaging system was able to accurately measure photochemical efficiency (FV/FM) and was highly correlated (r = 0.92) with the handheld fluorometer values. Additionally, the fluorescence imaging system was able to track the decrease in photochemical efficiency due to treatment of DCMU over a seven-day period. This indicates the system’s ability to capture the temporal dynamics of the plants response to this induced stress, which has comparable dynamics to abiotic and biotic stressors found in field environments. With the validation of the fluorescence imaging system, physiological and genetic studies can be undertaken that leverage the fluorescence imaging capabilities and throughput of the field scanalyzer.