Plant Photoreceptor-Mediated Signal Transduction

Both genetic and environmental factors influence growth and development of any living organism. Plant development is very plastic and is constantly modulated by environmental fluctuations. Being photoautotrophic plants are particularly sensitive to their light environment. Light affects all aspects of the plant life cycle. To optimize growth according to ambient light conditions plants evolved several classes of photoreceptors including the UV-A/blue light sensing cryptochromes and phototropins and the phytochromes maximally absorbing red/far-red light. The coordinated action of all these light receptors allows plants to fine-tune their development.

We focus our attention on two characteristic plant responses to light: phototropism which is the ability of plant stems to reorient their growth towards a unilateral source of light and shade avoidance which in shade intolerant plants such as Arabidopsis triggers elongation growth responses enabling the plant to reach unfiltered sunlight. Both light-responses contribute to the maximization of plant growth in particular in low light conditions that are typical in dense plant populations.

• Focus on circadian rhythms
  Harmer, Stacey L.; Fankhauser, Christian; Webb, Alex A. R.
  Plant Physiology 10.1093/plphys/kiac353  SEP 28 2022
• Shade suppresses wound-induced leaf repositioning through a mechanism involving PHYTOCHROME KINASE SUBSTRATE (PKS) genes.
  Fiorucci A.S., Michaud O., Schmid-Siegert E., Trevisan M., Allenbach Petrolati L., Çaka Ince Y., Fankhauser C.
  PLoS genetics, 18 (5) pp. https://doi.org/10.1371/journal.pgen.1010213   2022
• Phototropin-mediated perception of light direction in leaves regulates blade flattening
  Legris, Martina; Szarzynska-Erden, Bogna Maria; Trevisan, Martine; Petrolati, Laure Allenbach; Fankhauser, Christian
  Plant Physiology, 10.1093/plphys/kiab410  NOV 2021
• Architecture and plasticity: optimizing plant performance in dynamic environments
  Pierik, Ronald; Fankhauser, Christian; Strader, Lucia C.; Sinha, Neelima
  Plant Physiology, 10.1093/plphys/kiab402  NOV 2021
• AT the Onset of DNA Replication in Arabidopsis.
  Fiorucci A.S.,
  Plant physiology, 183 (1) pp. 19-20.  https://doi.org/10.1104/pp.20.00411  2020
• Low Blue Light Enhances Phototropism by Releasing Cryptochrome1-Mediated Inhibition of PIF4 Expression
  Boccaccini, Alessandra; Legris, Martina; Krahmer, Johanna; Allenbach-Petrolati, Laure; Goyal, Anupama; Galvan-Ampudia, Carlos; Vernoux, Teva; Karayekov, Elizabeth; Casal, Jorge J; Fankhauser, Christian
  Plant Physiology 10.1104/pp.20.00243, AUG 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
• A light-dependent molecular link between competition cues and defence responses in plants
  Fernandez-Milmanda, Guadalupe L.; Crocco, Carlos D.; Reichelt, Michael; Mazza, Carlos A.; Koellner, Tobias G.; et al.
  Nature Plants   DOI: 10.1038/s41477-020-0604-8, Published: MAR 2020
• PHYTOCHROME INTERACTING FACTOR 7 is important for early responses to elevated temperature in Arabidopsis seedlings
  Fiorucci, Anne-Sophie; Galvao, Vinicius Costa; Ince, Yetkin Caka; Boccaccini, Alessandra; Goyal, Anupama; et al.
  New Phytologist 226 (1): 50-58 DOI: 10.1111/nph.16316 APR 2020
• Molecular mechanisms underlying phytochrome-controlled morphogenesis in plants
  Legris, Martina; Ince, Yetkin Caka; Fankhauser, Christian
  Nature Communications, doi: 10.1038/s41467-019-13045-0   OCT 20129
• PIF transcription factors link a neighbor threat cue to accelerated reproduction in Arabidopsis
  Galvao, VC; Fiorucci, AS; Trevisan, M; Franco-Zorilla, JM; Goyal, A; Schmid-Siegert, E; Solano, R; Fankhauser, C
  NATURE COMMUNICATIONS, 10 10.1038/s41467-019-11882-7 SEP 5 2019
• Changes in resource partitioning between and within organs support growth adjustment to neighbor proximity in Brassicaceae seedlings
  de Wit, M; George, GM; Ince, YC; Dankwa-Egli, B; Hersch, M; Zeeman, SC; Fankhauser, C
  PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 115 (42):E9953-E9961; 10.1073/pnas.1806084115 OCT 16 2018
• 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
• A phosphorylation switch turns a positive regulator of phototropism into an inhibitor of the process
  Schumacher, P; Demarsy, E; Waridel, P; Petrolati, LA; Trevisan, M; Fankhauser, C
  NATURE COMMUNICATIONS, 9 10.1038/s41467-018-04752-1 JUN 19 2018

• Responses of plants to their light environment
• Plant photoreceptors and signal transduction mechanisms
• Phototropism
• Shade avoidance
• Role of the circadian clock in plant growth responses

• NCCR “Plant Survival” chloroplast responses to changing light conditions.
• SystemsX.ch “Plant growth in a changing environment”. Effects of the biotic and abiotic (e.g. light) environment on plant growth.
• Modeling of photoreceptor-mediated growth responses in collaboration with mathematicians and bio-informatitians.
• Development of imaging systems to record plant growth with high temporal and spatial resolution
• Genome-wide regulation of gene expression