Identification and characterization of chloroplast C3 and C4 monocarboxylate and dicarboxylate transporters, and their use in engineering single cell

C4 photosynthesis is a highly efficient form of photosynthesis that depends on cyclical metabolite transport to enhance CO2 concentration inside photosynthetically active chloroplasts. Our understanding of the molecular machinery that facilitate this metabolite cycle in maize, the most important C4 crop, is still incomplete. Specifically, the genes encoding the proteins that facilitate import and export of malate and pyruvate respectively from bundle sheath cell chloroplasts, and the gene encoding the protein that imports pyruvate into the mesophyll cell chloroplast, have yet to be identified or characterised. The first phase of my DPhil project will aim to identify these maize transporters, using a bioinformatic screen, followed by a novel experimental bacterial screen for plant transporter function, to accelerate the discovery process. The second phase of my DPhil project will utilize one of these newly discovered transporters, as well as previously characterized transporters in maize or bacteria, to attempt to engineer a single-cell C4 carbon-concentrating mechanism into the model C3 plant Arabidopsis thaliana. This would represent a significant step forward in the current effort to engineer the enhanced efficiency of C4 photosynthesis into C3 crop plants such as rice and wheat.

BBSRC priority areas:
Data driven biology. Food, nutrition and health. Sustainably enhancing agricultural production. Systems approaches to the biosciences.