CAREER: Enhancing heat resistance of carbon fixation via differential Rubisco subunit expression

Plants capture carbon dioxide from the air through photosynthesis, helping to sustain food production and life on Earth. However, variable temperatures, such as heat waves or cold snaps, threaten this process. This is, in part, because the central carbon-fixing enzyme in plants, Rubisco, performs less efficiently under temperature stress. This CAREER project will investigate how plants naturally adjust Rubisco function when temperatures change, focusing on how they do this by changing which small protein subunits are incorporated into the enzyme. Understanding this process could reveal new strategies for improving photosynthesis in crops, supporting long-term goals in agricultural biotechnology and food security. The project will also advance education and public engagement by training undergraduate students, graduate students, and postdoctoral researchers to communicate the long-term promise of fundamental science through science fiction writing. These activities will help broaden public understanding of how basic biological discoveries can lead to future technologies. The research will determine how temperature-responsive Rubisco small subunits influence carbon-fixation kinetics, enzyme stability, and plant growth. The project will first test this mechanism in Arabidopsis thaliana using Rubisco synthetic biology expression systems, biochemical assays, protein-stability measurements, plant transformation, and whole-plant growth analyses. It will then examine whether similar temperature-dependent Rubisco small-subunit responses occur across diverse land plants, including agriculturally important species, by combining gene-expression analysis, protein-level measurements, comparative sequence analysis, and kinetic characterization of engineered Rubisco variants. Finally, the project will test whether activity-stability tradeoffs can explain how different small subunits tune Rubisco function at different temperatures. By linking natural variation, synthetic biology, protein biochemistry, and plant biotechnology, this work will define molecular principles that may guide future engineering of temperature-adapted carbon fixation in crops. The integrated education plan will support undergraduate research training and develop science communication workshops that culminate in a freely available collection of science fiction stories written by scientists. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2542189 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT,01003031DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Laura Gunn | Institution: Cornell University, ITHACA, NY | Award Amount: $1,010,190 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2542189 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2542189.html