Laura Gunn, an assistant professor from the School of Integrative Plant Science Plant Biology Section in the College of Agriculture and Life Sciences at Cornell, and her colleagues have made a significant breakthrough in enhancing plant productivity and boosting carbon sequestration. They managed to integrate crucial parts of a highly efficient red algae into a tobacco plant, using bacteria as an intermediary.
This study, which represents a significant step towards improved agricultural efficiency, was recently featured on the cover of Nature Plants.
The study centers on Rubisco, the most abundant protein across every ecosystem on Earth. Rubisco performs the first step of One
“RsRubisco is not very efficient, but it is very closely related to GmRubisco – they’re like cousins – which means that, unlike land-plant Rubisco, it accepts the grafted sequences,” Gunn said. “RsRubisco also doesn’t need any special chaperones for it to fold and assemble in land plants.”
The change increased the carboxylation rate – the speed at which Rubisco starts the carbon fixation process – by 60%, increased carboxylation efficiency by 22%, and improved RsRubisco’s ability to distinguish between carbon dioxide and oxygen by 7%. The authors then transplanted their bacterial mutant into tobacco, where it doubled photosynthesis and plant growth, compared to tobacco grown with unaltered RsRubisco. Tobacco is the easiest land plant in which to manipulate Rubisco and so serves as the test case for developing a more efficient Rubisco that can be transferred to more agronomically relevant species, Gunn said.
“We’re not at the point where we’re outperforming wild-type tobacco, but we’re on the right trajectory,” Gunn said. “We only need fairly modest improvements to Rubisco performance, because even a very small increase over a whole growing season can lead to massive changes in plant growth and yield, and the potential applications span many sectors: higher agricultural production; more efficient and affordable biofuel production; carbon sequestration approaches; and artificial energy possibilities.”
Reference: “Grafting Rhodobacter sphaeroides with red algae Rubisco to accelerate catalysis and plant growth” by Yu Zhou, Laura H. Gunn, Rosemary Birch, Inger Andersson and Spencer M. Whitney, 8 June 2023, Nature Plants.
DOI: 10.1038/s41477-023-01436-7
The research was supported by the Australian Research Council Centre of Excellence for Translational Photosynthesis, Formas Future Research Leaders and the European Regional Development Fund.