A method for the production of plants with altered photorespiration and improved CO2 fixation
Processes and Methods (incl. Screening) : Chemical
Processes and Methods (incl. Screening) : Life Sciences-HTS/HCS
Scientists from the Max-Planck-Institute for Terrestrial Microbiology and the HHU Düsseldorf have developed a method for generating transgenic plants with altered photorespiration.
Their invention applies the ß-hydroxyaspartate cycle (BHAC), a metabolic pathway that they characterized in bacteria, to circumvent the naturally occurring photorespiration pathway in plants. The BHAC is carbon-neutral, while the natural photorespiration pathway of plants is carbon-negative. Furthermore, the BHAC is also more energy-efficient than natural plant photorespiration. Taken together, these properties of the BHAC promise to increase carbon fixation and therefore crop yield in the transgenic plants.
The inventors have successfully integrated four essential genes of the BHAC in plant peroxisomes, where high concentrations of photorespiration-derived glyoxylate is present. These genes encode for enzymes that funnel the photorespiratory glyoxylate efficiently into the central metabolism of the plant.
Gas exchange measurements and metabolic profiling confirmed that the newly developed plants conserve nitrogen and accumulate signature metabolites of the BHAC. At the current stage, the prototype plants did not show any gain in the amount of CO2 assimilated via photosynthesis at the expense of the CO2 released by photorespiration. It was determined that several bottlenecks still mask the full potential of the BHAC, and these will be resolved in future research.
To fully appreciate the gain in carbon fixed and ultimately in yield, the pathway will be further improved, guided by kinetic and genome-scale metabolic models. Prototyping in model plants allows identifying shortcomings before moving to a target crop, thus speeding up the development process. To this end, the inventors and their collaboration partners are currently testing the newly implemented pathway in a set of model organisms of increasing cellular and anatomical complexity before moving to its final target: the sunflower, an important oilseed crop in Europe.
We are now looking for a collaboration partner to further develop this exciting project.
A PCT application was filed on 5.08.2020.
Roell, M.S.; Schada von Borzyskowski, L.; Westhoff, P.; Plett, A.; Paczia, N.; Claus, P.; Schlueter, U.; Erb, T.J.; Weber, A.P.M.: A synthetic C4 shuttle via the β-hydroxyaspartate cycle in C3 plants. Proceedings of the National Academy of Sciences (2021) 118(21) e2022307118. DOI: https://doi.org/10.1073/pnas.2022307118
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