Abstract

C4 photosynthesis is a suite of biochemical, ultrastructural, and anatomical modifications that serve to concentrate CO2 around the enzyme RuBisCO. These modifications are typically associated with the partitioning of photosynthetic reactions between mesophyll and bundle sheath cells. Currently while a significant amount of fundamental C4 research is being carried out using dicot models, there is a humanitarian incentive to apply our understanding in monocots. For this reason and to expand upon basic scientific understanding it has been suggested Setaria viridis is utilised as a new monocot model of C4 photosynthesis. Since maize is currently the best studied C4 monocot I intend to extend our understanding of maize promoters by exploring how they perform in Setaria. Simultaneously I intend on examining the orthologus Setaria promoters to enable a comparison. To study cis elements I have established a vector system to place maize and Setaria PEPC and PPDK promoter regions upstream of GUS , and improved an infiltration protocol to transiently transform Setaria. To complement this and study trans factors I have isolated two complexes in maize that bind the PEPC promoter. In the future I intend to test whether protein complexes that bind Setaria promoters can be isolated. With these two aspects of my project I aim to use Setaria viridis as a new model to understand C4 gene regulation.