Strigolactones inhibit caulonema elongation and cell division in the moss Physcomitrella patens

PLoS One. 2014 Jun 9;9(6):e99206. doi: 10.1371/journal.pone.0099206. eCollection 2014.


In vascular plants, strigolactones (SLs) are known for their hormonal role and for their role as signal molecules in the rhizosphere. SLs are also produced by the moss Physcomitrella patens, in which they act as signaling factors for controlling filament extension and possibly interaction with neighboring individuals. To gain a better understanding of SL action at the cellular level, we investigated the effect of exogenously added molecules (SLs or analogs) in moss growth media. We used the previously characterized Ppccd8 mutant that is deficient in SL synthesis and showed that SLs affect moss protonema extension by reducing caulonema cell elongation and mainly cell division rate, both in light and dark conditions. Based on this effect, we set up bioassays to examine chemical structure requirements for SL activity in moss. The results suggest that compounds GR24, GR5, and 5-deoxystrigol are active in moss (as in pea), while other analogs that are highly active in the control of pea branching show little activity in moss. Interestingly, the karrikinolide KAR1, which shares molecular features with SLs, did not have any effect on filament growth, even though the moss genome contains several genes homologous to KAI2 (encoding the KAR1 receptor) and no canonical homologue to D14 (encoding the SL receptor). Further studies should investigate whether SL signaling pathways have been conserved during land plant evolution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bryophyta / drug effects*
  • Bryophyta / growth & development
  • Flowers / drug effects
  • Flowers / growth & development
  • Lactones / chemistry
  • Lactones / pharmacology*
  • Light
  • Mutation
  • Plant Cells / drug effects*
  • Plant Cells / metabolism
  • Plant Growth Regulators / metabolism
  • Plant Proteins / genetics
  • Plant Proteins / metabolism


  • 5-deoxystrigol
  • GR24 compound
  • Lactones
  • Plant Growth Regulators
  • Plant Proteins

Grants and funding

H.P. was supported by a PhD fellowship from the Ministère de l'Education Nationale, de la Recherche et de la Technologie (MENRT). The authors are grateful to the Agence Nationale de la Recherche (contract ANR-12-BSV6-004-01) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.