BAS1: A gene regulating brassinosteroid levels and light responsiveness in Arabidopsis

Proc Natl Acad Sci U S A. 1999 Dec 21;96(26):15316-23. doi: 10.1073/pnas.96.26.15316.

Abstract

The Arabidopsis bas1-D mutation suppresses the long hypocotyl phenotype caused by mutations in the photoreceptor phytochrome B (phyB). The adult phenotype of bas1-D phyB-4 double mutants mimics that of brassinosteroid biosynthetic and response mutants. bas1-D phyB-4 has reduced levels of brassinosteroids and accumulates 26-hydroxybrassinolide in feeding experiments. The basis for the mutant phenotype is the enhanced expression of a cytochrome P450 (CYP72B1). bas1-D suppresses a phyB-null allele, but not a phyA-null mutation, and partially suppresses a cryptochrome-null mutation. Seedlings with reduced BAS1 expression are hyperresponsive to brassinosteroids in a light-dependent manner and display reduced sensitivity to light under a variety of conditions. Thus, BAS1 represents one of the control points between multiple photoreceptor systems and brassinosteroid signal transduction.

Publication types

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

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / radiation effects
  • Arabidopsis Proteins
  • Brassinosteroids
  • Cholestanols / pharmacology
  • Cryptochromes
  • Dose-Response Relationship, Drug
  • Dose-Response Relationship, Radiation
  • Drosophila Proteins*
  • Eye Proteins*
  • Flavoproteins / genetics
  • Genes, Plant*
  • Light
  • Mutation
  • Peroxidases / genetics*
  • Peroxiredoxins
  • Photoreceptor Cells*
  • Photoreceptor Cells, Invertebrate*
  • Phytochrome / genetics
  • Phytochrome B
  • Phytosterols / biosynthesis*
  • Plants, Toxic
  • Receptors, G-Protein-Coupled
  • Signal Transduction
  • Steroids, Heterocyclic / pharmacology
  • Suppression, Genetic
  • Tobacco / genetics
  • Transcription Factors*
  • Transformation, Genetic

Substances

  • Arabidopsis Proteins
  • Brassinosteroids
  • CRY1 protein, Arabidopsis
  • Cholestanols
  • Cryptochromes
  • Drosophila Proteins
  • Eye Proteins
  • Flavoproteins
  • PHYB protein, Arabidopsis
  • Phytosterols
  • Receptors, G-Protein-Coupled
  • Steroids, Heterocyclic
  • Transcription Factors
  • cry protein, Drosophila
  • Phytochrome
  • Phytochrome B
  • Peroxidases
  • BAS1 protein, Arabidopsis
  • Peroxiredoxins
  • brassinolide