Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Light-induced, dark-reversible color shifts in petals of Phlox

  • G S Björn
  • W Braune
  • Lars Olof Björn
Publishing year: 1985
Language: English
Pages: 445-448
Publication/Series: Physiologia Plantarum
Volume: 64
Issue: 4
Document type: Journal article
Publisher: Wiley Online Library

Abstract english

Flowers of some Phlox (Phlox x paniculata L.) varieties undergo daily colour shifts, being blue in the early morning, turning red during the day, and returning to blue in the evening. The colour shift, which occurs only in the upper (adaxial) petal surfaces, is due to the daily changes in ambient light. In the laboratory, colour shifts could be induced by 2.5 h of ultraviolet, visible or far-red light and recorded by reflectance spectrophotometry.

There are indications that irradiations with different kinds of light cause qualitatively different colour shifts, and that thus more than one photoreceptor pigment and more than one primary light reaction may be involved. The presence of phytochrome was demonstrated in petals of white Phlox flowers by in vivo transmission spectrophotometry. It is therefore possible that colour shifts in coloured Phlox flowers are mediated by phytochrome. Possibly the movement of ions (e.g. hydrogen ions) into or out of the vacuole (where the visible pigments are located) is affected by light absorption in a pigment in the tonoplast.


  • Biological Sciences


  • ISSN: 0031-9317
Lars Olof Björn
E-mail: lars_olof [dot] bjorn [at] biol [dot] lu [dot] se

Professor emeritus

Molecular Cell Biology

+46 46 222 72 53