CIBSS Launchpad Funds Recipients 2022

Dr. Sarah Courbier

Postdoc

Dr. Sarah Courbier

Contact

Dr. Sarah Courbier
Department of Molecular Plant Physiology, University of Freiburg, Faculty of Biology and CIBSS

T +49 761 203 67861
sarah.courbier(at)cibss.uni-freiburg.de

Further Information

Selected publications:

  • Mechanisms of far-red light-mediated dampening of defense against Botrytis cinerea in tomato leaves.
    Courbier S, Snoek BL, Kajala K, Li L, van Wees SCM, Pierik R.
    Plant Physiol. 2021 Nov 3;187(3):1250-1266
  • Far-red light promotes Botrytis cinerea disease development in tomato leaves via jasmonate-dependent modulation of soluble sugars.
    Courbier S, Grevink S, Sluijs E, Bonhomme PO, Kajala K, Van Wees SCM, Pierik R.
    Plant Cell Environ. 2020 Nov;43(11):2769-2781
  • Canopy light quality modulates stress responses in plants.
    Courbier S, Pierik R.
    iScience. 2019 Dec 20;22:441-452.
  • Far-red radiation increases dry mass partitioning to fruits but reduces Botrytis cinerea resistance in tomato.
    Ji Y, Ouzounis T, Courbier S, Kaiser E, Nguyen PT, Schouten HJ, Visser RGF, Pierik R, Marcelis LFM, Heuvelink E
    Environmental and Experimental Botany 2019;168: 103889
  • Genomics analysis of Aphanomyces spp. identifies a new class of oomycete effector associated with host adaptation.
    Gaulin E, Pel MJC, Camborde L, San-Clemente H, Courbier S, Dupouy MA, Lengellé J, Veyssiere M, Le Ru A, Grandjean F, Cordaux R, Moumen B, Gilbert C, Cano LM, Aury JM, Guy J, Wincker P, Bouchez O, Klopp C, Dumas B.
    BMC Biol. 2018 Apr 18;16(1):43.

The emerging role of TARGET OF RAPAMYCIN in the shade-induced susceptibility in plants.

Light is a key parameter for plant growth and survival. Plants absorb blue and red light (R) to fuel photosynthesis and reflect far-red light (FR) back to their surroundings. The reflection and subsequent accumulation of FR leads to a decrease in the ratio between R and FR (low R:FR) in the canopy. Low R:FR is sensed by a set of specialized photoreceptors called phytochromes and constitutes an early warning signal for close neighbouring vegetation (shade). Low R:FR perception by phytochromes triggers strong and rapid growth responses, known as the shade avoidance syndrome, mostly driven by the growth hormone auxin and allowing plants to grow taller than their neighbours. In addition to eliciting growth responses, low R:FR promote plant susceptibility to pathogen attacks. Indeed, shade strongly dampens defence hormone signalling; a process referred to as shade-induced susceptibility. Interestingly, this dampening of plant defence by low R:FR has long been attributed to a direct interplay between light and defence hormone signalling. However, other mechanisms, also affected by shade, have not yet been considered as potential components of the shade-induced susceptibility.

Recently, we found that plants experiencing low R:FR accumulate glucose, which is closely associated with faster lesion development by pathogens. Yet, the molecular mechanism behind how glucose accumulation leads to increased pathogen susceptibility remains elusive. In a recent RNA-sequencing study, we found that TARGET OF RAPAMYCIN (TOR) is upregulated in response to low R:FR. In eukaryotes, TOR is a master growth regulator activated by glucose and auxin, both strongly elevated in shaded plants, too. I am currently investigating if and how shade signals could promote growth at the expense of defence in a TOR-dependent manner. The gained insights will be instrumental for understanding how plants respond to shade to engineer pathogen-resilient crops, which can be grown at higher densities.