Modulation of Ambient Temperature-Dependent Flowering in Arabidopsis thaliana by Natural Variation of FLOWERING LOCUS M

PLoS Genet. 2015 Oct 22;11(10):e1005588. doi: 10.1371/journal.pgen.1005588. eCollection 2015 Oct.


Plants integrate seasonal cues such as temperature and day length to optimally adjust their flowering time to the environment. Compared to the control of flowering before and after winter by the vernalization and day length pathways, mechanisms that delay or promote flowering during a transient cool or warm period, especially during spring, are less well understood. Due to global warming, understanding this ambient temperature pathway has gained increasing importance. In Arabidopsis thaliana, FLOWERING LOCUS M (FLM) is a critical flowering regulator of the ambient temperature pathway. FLM is alternatively spliced in a temperature-dependent manner and the two predominant splice variants, FLM-ß and FLM-δ, can repress and activate flowering in the genetic background of the A. thaliana reference accession Columbia-0. The relevance of this regulatory mechanism for the environmental adaptation across the entire range of the species is, however, unknown. Here, we identify insertion polymorphisms in the first intron of FLM as causative for accelerated flowering in many natural A. thaliana accessions, especially in cool (15°C) temperatures. We present evidence for a potential adaptive role of this structural variation and link it specifically to changes in the abundance of FLM-ß. Our results may allow predicting flowering in response to ambient temperatures in the Brassicaceae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing / genetics
  • Arabidopsis / genetics*
  • Arabidopsis / growth & development
  • Arabidopsis Proteins / biosynthesis
  • Arabidopsis Proteins / genetics*
  • Flowers / genetics*
  • Gene Expression Regulation, Plant
  • Global Warming
  • MADS Domain Proteins / biosynthesis
  • MADS Domain Proteins / genetics*
  • Mutagenesis, Insertional / genetics*
  • Polymorphism, Genetic
  • Seasons
  • Temperature


  • Arabidopsis Proteins
  • FLM protein, Arabidopsis
  • MADS Domain Proteins

Grant support

Research in the laboratory of CS and MS is supported by the SPP1530 of the Deutsche Forschungsgemeinschaft. CS and KFXM acknowledge financial support from the SFB924 of the Deutsche Forschungsgemeinschaft. MS and DW receive financial support from the SFB1101 of the Deutsche Forschungsgemeinschaft. DW is also supported by the Max-Planck-Society, MS also receives financial support from ERA-CAPS and ERA-PG. UL receives support from the Graduate School of the Wissenschaftszentrum Weihenstephan at the Technische Universität München. CS receives support from Nirit and Michael Shaoul Fund for Visiting Scholars and Fellows. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.