Productivity in many crops is limited by CO2 availability and water use. The CAPP project aims to overcome those limitations by transferring a performance-enhancing Carbon Concentrating Mechanism (CCM) from green algae to higher plants. This project will yield significant advances in our understanding in the function of CCMs, which remain mysterious even though nearly all algae use them to assimilate CO2. If successful, the project will be a key step towards significant increases in crop productivity. More generally, this project represents one of the first attempts at transplanting a complex system from one organism to another, and thus will present many opportunities for learning general principles that will be useful as mankind increasingly attempts to engineer biology.
CAPP2 will focus on understanding the pyrenoid, an organelle at the core of the algal CCM, and re-creating its key features in the C3 plant Arabidopsis. Structure, assembly and regulation of the pyrenoid will be studied in the green alga Chlamydomonas, using mutants, light and electron microscopy, and biochemistry. Components will be introduced into Arabidopsis, and the impact on productivity will be modeled and measured. Additionally, a Förster Resonance Energy Transfer (FRET) nanosensor will be developed to measure concentrations of bicarbonate with sub-cellular resolution in vivo; the sensor will be applied to characterize the CCM in both Chlamydomonas and Arabidopsis.
