Cluster of Excellence –
University of Freiburg

Prof. Andreas Hiltbrunner

Prof. Andreas Hiltbrunner

Department of Botany, Institute of Biology II, University of Freiburg

+49 761 203 2709

Light Perception and Signalling in Plants

Phytochromes are red/far-red photoreceptors in plants, which are important to adapt growth and development to the environment. They localise to the cytosol in the dark and translocate into the nucleus in plants exposed to light. Phytochrome interacting factors (PIFs), COP1 and SPA proteins act downstream of phytochromes and actively suppress photomorphogenic development. After transport into the nucleus, light activated phytochromes target PIFs for degradation and inactivate the COP1/SPA complex to promote photomorphogenesis. Understanding how phytochrome nuclear transport is regulated, how it is linked to downstream signalling and how downstream signalling results in regulation of gene expression are major topics in our research.

Phytochromes are ubiquitous in the plant kingdom and also present in green algae, mosses and ferns, i.e. in cryptogams. Both in seed plants and cryptogams the phytochrome families consist of several members, which have overlapping but also specific functions. Using Arabidopsis thaliana and Physcomitrella patens as model systems for seed plants and cryptogams, we also investigate how species-specific light signalling pathways evolved.

10 selected publications:

  • High-level expression and phosphorylation of phytochrome B modulates flowering time in Arabidopsis.
    Hajdu A, Adam E, Sheerin DJ, Dobos O, Bernula P, Hiltbrunner A, Kozma-Bognar L, Nagy F (2015).
    Plant J 83: 794-805
  • Light-Activated Phytochrome A and B Interact with Members of the SPA Family to Promote Photomorphogenesis in Arabidopsis by Reorganizing the COP1/SPA Complex.
    Sheerin DJ, Menon C, Zur Oven-Krockhaus S, Enderle B, Zhu L, Johnen P, Schleifenbaum F, Stierhof YD, Huq E, Hiltbrunner A (2015).
    Plant Cell. 27(1):189-201. 
  • An evolutionarily conserved signaling mechanism mediates far-red light responses in land plants.
    Possart A, Hiltbrunner A (2013)
    Plant Cell 25:102-114.
  • Interaction with plant transcription factors can mediate nuclear import of phytochrome B.
    Pfeiffer A, Nagel M-K, Popp C, Wüst F, Bindics J, Viczian A, Hiltbrunner A, Nagy F, Kunkel T, Schäfer E (2012).
    Proc Natl Acad Sci USA 109:5892-5897.
  • Nuclear phytochrome A signaling promotes phototropism in Arabidopsis.
    Kami C, Hersch M, Trevisan M, Genoud T, Hiltbrunner A, Bergmann S, Fankhauser C (2012).
    Plant Cell 24:566-576.
  • Photoconversion and nuclear trafficking cycles determine phytochrome A’s response profile to far-red light.
    Rausenberger J, Tscheuschler A, Nordmeier W, Wüst F, Timmer J, Schäfer E, Fleck C*, Hiltbrunner A* (2011).
    Cell 146:813-825.
    * corresponding authors
  • FHY1 mediates nuclear import of the light-activated phytochrome A photoreceptor.
    Genoud T, Schweizer F, Tscheuschler A, Debrieux D, Casal JJ, Schäfer E, Hiltbrunner A*, Fankhauser C* (2008).
    PLoS Genet 4:e1000143.
    corresponding authors
  • FHY1 and FHL act together to mediate nuclear accumulation of the phytochrome A photoreceptor.
    Hiltbrunner A, Tscheuschler A, Viczián A, Kunkel T, Kircher S, Schäfer E (2006).
    Plant Cell Physiol 47:1023-1034.
  • Nuclear accumulation of the phytochrome A photoreceptor requires FHY1.
    Hiltbrunner A, Viczián A, Bury E, Tscheuschler A, Kircher S, Tóth R, Honsberger A, Nagy F, Fankhauser C, Schäfer E (2005).
    Curr Biol 15:2125-2130.
  • The major protein import receptor of plastids is essential for chloroplast biogenesis.
    Bauer J*, Chen K*, Hiltbrunner A*, Wehrli E, Eugster M, Schnell DJ, Kessler F (2000)
    Nature 403:203-207.
    * equally contributing first authors