FOR 1261:  Specific Light Driven Reactions in Unicellular Model Algae

• Subject Area: Biology
• Term: from 2009 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 112805507

Light has major impacts on algae: (1) serving as energy source for photosynthesis, (2) triggering behavioural responses under the control of sensory photoreceptors and (3) entraining their circadian clocks by light-dark cycles. The recent sequencing of the genomes of two model organisms, the green alga Chlamydomonas reinhardtii and the diatom Phaeodactylum tricornutum, allow integrated genome and proteome analyses. Moreover, several molecular genetic tools have been developed on an international basis for these two algae in the past years. These efforts provide an efficient platform to perform an in-depth characterisation of relevant proteins involved in light-driven processes.
In C. reinhardtii, one focus will be on the functional and biophysical characterisation of selected photoreceptors, including channel- and enzyme-rhodopsins as well as a plant- and an animal-like cryptochrome (CRY). The second focus is on components of the light-signalling cascade (e.g. a SOUL heme-binding) that are closely connected with its eyespot apparatus. In the diatom P. tricornutum, we also analyse the function and biophysical properties of the CRYs as well as of the diatom aureochromes to highlight different or common features of light perception in these two algal lineages.
Our studies also include the mechanisms of light driven regulation of diatom photosynthesis on different levels, because diatoms contribute up to 20 percent to the primary production on Earth, and little is yet known about their photosynthesis.

• DFG Programme: Research Units

Projects

• Biological function of aureochromes in the diatom Phaeodactylum tricornutum (Applicants Kroth, Peter ;  Wilhelm, Christian )
• Central Project (Applicants Hegemann, Peter ;  Mittag, Maria )
• Central Project (Applicants Hegemann, Peter ;  Mittag, Maria ;  Weber, Andreas P.M. )
• Functional characterization of novel rhodopsins of Chlamydomonas and other algae (Applicant Hegemann, Peter )
• Light harvesting proteins in diatoms - functional heterogeneity and regulation (Applicant Büchel, Claudia )
• Light regulation of carbon fixation in diatoms (Applicant Kroth, Peter )
• Light responses of animal-like cryptochromes and aureochromes from microalgae (Applicant Kottke, Tilman )
• Studies on the structures and mechanisms of algal photoreceptors (Applicant Essen, Lars-Oliver )
• The function of the C-terminal half of Channelrhodopsins and of predicted novel rhodopsins from the green alga Chlamydomonas reinhardtii (Applicant Nagel, Georg )
• The involvement of cryptochromes in the light- and circadian signaling pathways in Chlamydomonas reinhardtii (Applicant Mittag, Maria )

• Spokesperson: Professorin Dr. Maria Mittag