Plant Molecular Biology

Sunlight is of utmost importance to plants, not only as energy source but also as an environmental signal regulating growth and development. An important and increasing part of the incident sunlight encompasses a segment of the ultraviolet-B region (UV-B; 280-315 nm) that is not entirely absorbed by the ozone layer in the stratosphere of the Earth. UV-B radiation is potentially harmful for any organism exposed to it, but is also used as an informational signal for which plants have evolved specific and sensitive UV-B perception systems promoting UV-B acclimation and tolerance. Our understanding of this UV-B sensory pathway is presently limited to a small number of major players, and even less is known on their interplay, regulations and mechanisms of action. The major aim of our laboratory is a better understanding of UV-B perception and signalling in plants that leads to UV-B acclimation and survival.

• A constitutively monomeric UVR8 photoreceptor confers enhanced UV-B photomorphogenesis
  Podolec, Roman; Lau, Kelvin; Wagnon, Timothee B.; Hothorn, Michael; Ulm, Roman
  Proceedings Of The National Academy Of Sciences Of The United States Of America   DOI: 10.1073/pnas.2017284118 FEB 9 2021
• Cryptochrome-mediated blue-light signalling modulates UVR8 photoreceptor activity and contributes to UV-B tolerance in Arabidopsis
  Tissot, Nicolas; Ulm, Roman
  Nature Communications, DOI: 10.1038/s41467-020-15133-y  MAR 12 2020
• UVR8-mediated inhibition of shade avoidance involves HFR1 stabilization in Arabidopsis
  Tavridou, Eleni; Schmid-Siegert, Emanuel; Fankhauser, Christian; Ulm, Roman
  Plos Genetics 10.1371/journal.pgen.1008797, MAY 2020
• Degradation of the transcription factors PIF4 and PIF5 under UV-B promotes UVR8-mediated inhibition of hypocotyl growth in Arabidopsis
  Tavridou, Eleni; Pireyre, Marie; Ulm, Roman
  Plant Journal,  DOI: 10.1111/tpj.14556, Published: FEB 2020
• Plant photoreceptors and their signaling components compete for COP1 binding via VP peptide motifs
  Lau, K; Podolec, R; Chappuis, R; Ulm, R; Hothorn, M
  EMBO JOURNAL, 38 (18):10.15252/embj.2019102140 SEP 16 2019
• Arabidopsis RUP2 represses UVR8-mediated flowering in noninductive photoperiods
  Arongaus, AB; Chen, S; Pireyre, M; Glockner, N; Galvao, VC; Albert, A; Winkler, JB; Fankhauser, C; Harter, K; Ulm, R
  GENES & DEVELOPMENT, 32 (19-20):1332-1343; 10.1101/gad.318592.118 OCT 1 2018
• Photoreceptor-mediated regulation of the COP1-SPA E3 ubiquitin ligase complex
  Podolec, Roman and Ulm, Roman
  Curr. Opin. Plant Biol. 45: 18-25, https://doi.org/10.1016/j.pbi.2018.04.018 MAY 2018
• Coping with 'Dark Sides of the Sun' through Photoreceptor Signaling 
  Demarsy, Emilie; Goldschmidt-Clermont, Michel; Ulm, Roman 
  TRENDS IN PLANT SCIENCE, 23 (3):260-271; https://doi.org/10.1016/j.tplants.2017.11.007 MAR 2018
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• UV-B response
• Photomorphogenesis
• MAP kinase phosphatases
• Abiotic stress responses

• Photobiology
• Environmental stress signalling