Project Details
Projekt
The evolution and role of photorespiration in C4 photosynthesis
Applicant
Professor Dr. Peter Westhoff
Subject Area
Plant Biochemistry and Biophysics
Term
from 2009 to 2016
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 91564084
The C4 photosynthetic pathway is an adaptation to cope with the high photorespiratory losses of CO2 which are caused by the oxygenase activity of ribulose bisphosphate carboxylase/oxygenase (Rubisco). C4 photosynthesis functions essentially as a CO2 pump that concentrates CO2 at the site of Rubisco thereby reducing the apparent photorespiration drastically. Nevertheless, photorespiration is still found in C4 plants, but is compartmentalised in the bundle-sheath cells. C4 plants evolved many times independently within the angiosperms indicating that in genetic terms it must have been relatively simple to evolve a C4 from a C3 species. It is commonly believed that the compartmentation of photorespiration in bundle-sheath cells occurred relatively early during C4 evolution and that the establishment of this photorespiratory CO2 pump was an essential, intermediate step in the evolutionary scenario. The goal of this project is (1) to understand the sequence of evolutionary events leading to this compartmentation of photorespiration in C4 plants and (2) to gain insight into the metabolic function of this pathway in C4 species. To pursue these goals the genus Flaveria serves as the model system. Flaveria was chosen because it contains C3 and C4 species, but also a whole range of C3-C4 intermediates allowing a fine mapping of the steps taken in the evolutionary trajectory towards C4 photosynthesis. In addition, the C4 species F. bidentis is transformable, thus reverse genetic approaches are feasible.
DFG Programme
Research Units
