Regulation of CO2 fixation in diatom plastids

• Applicant: Professor Dr. Peter Kroth
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2005 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 13513446

Diatoms are unicellular algae of great ecological importance. So far very little is known about the regulation of photosynthesis in these algae. We have been able to show that in diatoms (in contrast to land plants) several enzymes of the Calvin Cycle are not redox-regulated via thioredoxin. During the annotation of the genome of the diatom Phaeodactylum tricornutum we were able to identify several genes encoding thioredoxins that are targeted into the plastids, surprisingly including a thioredoxin h, which in other organisms is found exclusively in the cytosol. In addition we found that several Calvin cycle enzymes are encoded by multiple (up to four) gene copies. In this project we want to investigate the regulation of the Calvin cycle in diatoms by analysis of gene expression and enzymatic characterization of key enzymes. Furthermore we want to localize individual isoenzymes via expression of GFP-fusion proteins and to identify potential targets of thioredoxin by affinity chromatography.

• DFG Programme: Research Grants