Ecophysiology of Photosynthesis

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Plants can live, thrive, and survive in nearly every environment imaginable: from low altitude swamps to high altitude deserts, from the Antarctic peninsula to the Saharan Desert. Ecological physiology (ecophysiology) is about understanding the mechanisms behind how plants live and persist in their environment.

My research focuses on photosynthesis – the process by which plants convert carbon dioxide into sugars using light energy – and the physiological mechanisms behind plant stress tolerance. Extreme temperatures can cause photosynthesis to become dysfunctional: high temperatures can cause proteins to denature and lose function, while low temperatures can cause energy imbalances as enzyme function slows down. However, some plant species have special adaptations to adjust the machinery of photosynthesis to handle high and/or low temperature stress. My goal is to understand how these adaptations work and the timescales involved in acquiring stress tolerance (e.g. can the plant inherently tolerate high temperatures, or does it require an acclimation period to adjust). I address my research questions using techniques ranging from biochemistry and elemental analysis to gas exchange and modeling.

Recently, I started combining gas exchange with thermal and chlorophyll fluorescence imaging to understand photosynthetic responses in two dimensions. Part of this work has involved developing software for combining images and performing calculations across the ~20,000 pixels of each image. Below are GIFs showing the light response of non-photochemical quenching (NPQ), which is a method by which plant dissipate excess light energy as heat, and linear photosynthetic electron transport (J), which is used to provide energy for carbon fixation. The leaf patch is a 6 by 6 cm sector of a sunflower leaf.

NPQ
Light response of non-photochemical quenching (NPQ). Note the spatial heterogeneity across the leaf surface, and the increase in NPQ as absorbed light energy (upper left) increases.
ETR
Light response of photosynthetic electron transport (J). Note the relative spatial homogeneity compared to NPQ, and how J saturates at higher light intensities.

You can read more about my gas exchange mapping project here.

I am currently open and looking for collaborative opportunities. If you wish to contact me regarding opportunities or questions about my research, you can find my contact information here.

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Ecophysiology of Photosynthesis

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