Regulation of flowering time by light quality

Nature. 2003 Jun 19;423(6942):881-5. doi: 10.1038/nature01636.


The transition to flowering in plants is regulated by environmental factors such as temperature and light. Plants grown under dense canopies or at high density perceive a decrease in the ratio of red to far-red incoming light. This change in light quality serves as a warning of competition, triggering a series of responses known collectively as the 'shade-avoidance syndrome'. During shade avoidance, stems elongate at the expense of leaf expansion, and flowering is accelerated. Of the five phytochromes-a family of red/far-red light photoreceptors-in Arabidopsis, phytochrome B (phyB) has the most significant role in shade-avoidance responses, but the mechanisms by which phyB regulates flowering in response to altered ratios of red to far-red light are largely unknown. Here we identify PFT1 (PHYTOCHROME AND FLOWERING TIME 1), a nuclear protein that acts in a phyB pathway and induces flowering in response to suboptimal light conditions. PFT1 functions downstream of phyB to regulate the expression of FLOWERING LOCUS T (FT), providing evidence for the existence of a light-quality pathway that regulates flowering time in plants.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis / radiation effects*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • DNA-Binding Proteins / genetics
  • Epistasis, Genetic
  • Flowers / genetics
  • Flowers / growth & development*
  • Flowers / metabolism
  • Flowers / radiation effects*
  • Gene Expression Regulation, Plant
  • Light*
  • Molecular Sequence Data
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phenotype
  • Photoreceptor Cells*
  • Phytochrome / genetics
  • Phytochrome / metabolism
  • Phytochrome A
  • Phytochrome B
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA, Plant / genetics
  • RNA, Plant / metabolism
  • Time Factors
  • Transcription Factors / genetics


  • Arabidopsis Proteins
  • CONSTANS protein, Arabidopsis
  • DNA-Binding Proteins
  • FT protein, Arabidopsis
  • Nuclear Proteins
  • PFT1 protein, Arabidopsis
  • PHYA protein, Arabidopsis
  • PHYB protein, Arabidopsis
  • Phytochrome A
  • RNA, Messenger
  • RNA, Plant
  • Transcription Factors
  • Phytochrome
  • Phytochrome B

Associated data

  • GENBANK/AY170377