| Project Detail |
Proteomic characterisation of endosymbiotic chloroplasts in eukaryotic algae
Ocean photosynthesis is performed by cyanobacteria and eukaryotic algae. These eukaryotic algae originate via the endosymbiotic acquisition of chloroplasts, and many of the most prominent marine algal groups possess chloroplasts derived from the secondary or higher endosymbiotic uptake of eukaryotic red algae. The EU-funded ChloroMosaic programme aims to understand the fundamentals of the evolution and future ecology of the planet, explaining the success of the secondary red chloroplasts in the modern ocean. The secondary red chloroplasts are evolutionary mosaics and supported by nucleus-encoded proteins of the symbiont. ChloroMosaic will perform proteomic analysis of the dinoflagellate chloroplasts to identify proteins, enabling the dominant contribution of secondary red chloroplasts to marine production and defining potential biomarkers of the resilience of algal communities to anthropogenic climate change.
"Photosynthesis in the ocean is as significant as that of land plants, and is performed by a wide range of cyanobacteria and eukaryotic algae, the most abundant of which have originated through the secondary endosymbioses of red algae. Previously, I have shown that these ""secondary red chloroplasts"" are evolutionary mosaics, supported by nucleus-encoded proteins of symbiont, host and horizontally acquired origin; and that the most successful of these groups (diatoms, haptophytes and dinoflagellates) are connected to one another via chloroplast endosymbioses.
My research programme will answer a question of fundamental importance to the evolutionary history, and future ecology of the planet: why is the secondary red chloroplast so successful in the modern ocean? I will perform next-generation proteomic (LOPIT) characterisation of the dinoflagellate chloroplast, whose composition remains unknown; phylogenomic and spatial reconstruction of the pan-secondary red chloroplast proteome, using environmental sequence data from the Tara Oceans expedition; and phenotyping of proteins via CRISPR/Cas9 mutagenesis in the model diatom Phaeodactylum. I will focus on defining the proteins that underpin the dominant contributions of secondary red chloroplasts to marine primary production; and their unique success in high oceanic latitudes.
Thus far, I have characterised a mitochondria-associated transporter that facilitates photo-acclimation in secondary red chloroplasts under Fe limitation; and a complete glycolytic pathway that regulates diatom chloroplast metabolism in polar oceans. The phylogenetically-grounded insights from this project will connect a defining event in eukaryotic evolution, the endosymbiotic evolution of chloroplasts, to the functional biology of marine ecosystems; identify new proteins for optimising photosynthetic production in cultivable species; and define new biomarkers for the resilience of algal communities to anthropogenic climate change. |
