Assistant Professor

Department of Plant Biology
berkley@msu.edu

Research: Resolving photosynthetic fluxes in a changing world

Photosynthesis drives life on this planet by providing the oxygen, food and energy required to support “higher” life forms – including us humans. With increasing population, and accompanying changes in consumption and climate, it is vital to understand how photosynthesis will respond to these greater challenges and explore opportunities to hack it to produce more food, fuel and fiber more sustainably. Research in our lab therefore focuses on resolving the biochemical, cellular and canopy-level mechanisms that determine photosynthetic fluxes of carbon and oxygen with the end goal to better model plant response to climate change and engineer more efficient crops.

If we can’t model or measure it, we don’t understand it

For many years, we have been able to use classic methods in gas and energy exchange to understand on a net level how much carbon dioxide a plant takes up or how much oxygen it produces from water splitting under a given condition. These measurements helped produce elegant models that connect plant ecophysiology with biochemistry and are currently used to estimate how ecosystems or crop yields respond to future changes in temperature or carbon dioxide concentration. While these models are good, they rely on many assumptions which have not yet been validated – especially under increased temperatures. Our lab challenges these assumptions using next-generation advances in metabolic flux analysis and isotopic gas exchange analysis to understand how the models can be improved to better represent plant responses to increased temperature.

If we don’t understand it, we can’t make it better

As we develop improved models of carbon dioxide fixation and related metabolic fluxes, we identify targets for improving photosynthesis. We then implement these targets in silico or in living plants to see if the results are improved photosynthesis. We can also use these refined models to determine if we can make more accurate predictions about the response of plants to changing conditions.

Feel free to contact us with any questions about what we do.

Key Publications

1. Berkley J. Walker, Andy VanLoocke, Rebecca A. Slattery, Darren Drewry and Donald R. Ort. Chlorophyll can be reduced in crop canopies with little penalty to crop photosynthesis. Accepted. Plant Physiology
2. Berkley Walker, Andy VanLoocke, Carl J. Bernacchi and Donald R. Ort. (2016) The costs of photorespiration to food production now and in the future. Annual Review of Plant Biology 67, 107-129.
3. Berkley Walker and Donald R. Ort. (2015) Improved method for measuring the apparent CO₂ photocompensation point resolves the impact of multiple internal conductances to CO₂ to net gas exchange. Plant Cell & Environment 38 (11), 2462-2474.