B008-03
Quantifying high-temperature stress on canopy photosynthesis at the Temperature Free-Air Controlled Enhancement (T-FACE) experiment: the unique role of sun-induced chlorophyll fluorescence in capturing plant physiological stress

Monday, 7 December 2020: 07:08
Virtual
Hyungsuk Kimm, University of Illinois at Urbana Champaign, College of Agricultural, Consumer and Environmental Sciences, Urbana, United States, Kaiyu Guan, University of Illinois at Urbana Champaign, College of Agricultural, Consumer and Environmental Sciences, Urbana, IL, United States, Charles H Burroughs, University of Illinois at Urbana Champaign, Department of Plant Biology, Urbana, IL, United States, Bin Peng, University of Illinois at Urbana Champaign, National Center for Supercomputing Applications, Urbana, IL, United States, Elizabeth A. Ainsworth, University of Illinois at Urbana-Champaign, Department of Plant Biology and Carl. R. Woese Institute for Genomic Biology, Urbana, IL, United States, Carl Bernacchi, University of Illinois at Urbana-Champaign, Department of Plant Biology, Urbana, IL, United States, Caitlin Moore, University of Illinois at Urbana Champaign, Urbana, IL, United States, Etsushi Kumagai, Tohoku Agricultural Reseach center, National Agriculture and Food Research Organization, Morioka, Japan, Xi Yang, University of Virginia, Charlottesville, VA, United States, Genghong Wu, University of Illinois at Urbana Champaign, College of Agricultural, Consumers, and Environmental Sciences, Urbana, IL, United States and Joseph A Berry, Carnegie Institution for Science, Global Ecology, Stanford, CA, United States
Recorded Presentation
Abstract:
Major stress factors in the U.S. Corn Belt, high-temperature and accompanying high vapor pressure deficit, often affect plants without causing distinctive changes in plant canopy structure or canopy spectral signatures. Sun-induced chlorophyll fluorescence (SIF), because of its mechanistic link with photosynthesis, may better detect such stress than remote sensing techniques relying on spectral reflectance signature of canopy structural changes. However, our understanding of the physiological mechanisms and implications of SIF remains unclear. In this study, we measured SIF at a uniquely designed canopy-warming experiment, Temperature Free-Air Controlled Enhancement (T-FACE), to explore physiological mechanisms associated with SIF and the potential of SIF to detect temperature stress. The experiment provided a gradient of stress conditions with multiple plots where soybean canopy temperature was increased from 1.5 to 6 °C above ambient to enable an in-depth exploration of SIF response to increased temperature. We found that SIF yield, which is normalized by radiation and canopy structure from SIF, effectively captured dynamic plant responses to high-temperature conditions. Here, SIF yield directly indicated plant responses due to its tight correlation with light use efficiency of photosynthesis (R2=0.8). Then, we attributed SIF yield variability to canopy structural and plant physiological information and confirmed a substantial contribution of physiological information to SIF yield (partial correlation r=0.60 and -0.23, respectively). However, no comparable physiological information was found from an advanced vegetation index, NIRv,rad (partial correlation r=0.60 and -0.02, respectively for canopy structural and plant physiological information). Our findings suggest that SIF contains unique information about plant physiology and confirms the potential of SIF for physiological investigations and agricultural applications.
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