Blue-light promotion of flowering is absent in hy4 mutants of Arabidopsis

Planta. 1996;200(2):278-80. doi: 10.1007/BF00208319.


Loss of a blue-light photoreceptor in the hy4 mutants of Arabidopsis thaliana (L.) Heynh substantially delayed flowering (> 100 d to flower vs. 40-50 d), especially with blue light exposure from lamps lacking much red (R) and/or far-red (FR) light. Red night breaks were promotory but flowering was still later for the hy4-101 mutant. However, with exposure to light from FR-rich lamps, flowering of all mutants was early and no different from the wild type. Thus, flowering of Arabidopsis involves a blue-light photoreceptor and other, often more effective photoreceptors. The latter may involve phytochrome photoresponses to R and FR, but with little or no phytochrome response to blue wave-lengths.

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / growth & development*
  • Gene Deletion
  • Light*
  • Photoreceptor Cells / physiology*
  • Photosynthetic Reaction Center Complex Proteins / genetics*


  • Photosynthetic Reaction Center Complex Proteins