title: BAS1: A gene regulating brassinosteroid levels and light responsiveness in Arabidopsis.
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.
authors.affiliation: Plant Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Neff
authors.forename: S M
authors.initials: SM
authors.lastname: Nguyen
authors.forename: E J
authors.initials: EJ
authors.lastname: Malancharuvil
authors.forename: S
authors.initials: S
authors.lastname: Fujioka
authors.forename: T
authors.initials: T
authors.lastname: Noguchi
authors.forename: H
authors.initials: H
authors.lastname: Seto
authors.forename: M
authors.initials: M
authors.lastname: Tsubuki
authors.forename: T
authors.initials: T
authors.lastname: Honda
authors.forename: S
authors.initials: S
authors.lastname: Takatsuto
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: J
authors.initials: J
authors.lastname: Chory
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols / Q000494:pharmacology; D056931:Cryptochromes; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics; D017343:Genes, Plant; D008027:Light; D009154:Mutation; D010544:Peroxidases / Q000235:genetics*; D054464:Peroxiredoxins; D010786:Photoreceptor Cells; D017956:Photoreceptor Cells, Invertebrate; D010834:Phytochrome / Q000235:genetics; D051939:Phytochrome B; D010840:Phytosterols / Q000096:biosynthesis*; D010947:Plants, Toxic; D043562:Receptors, G-Protein-Coupled; D015398:Signal Transduction; D013260:Steroids, Heterocyclic / Q000494:pharmacology; D013489:Suppression, Genetic; D014026:Nicotiana / Q000235:genetics; D014157:Transcription Factors; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; C538962:CRY1 protein, Arabidopsis; D002777:Cholestanols; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; C497952:PHYB protein, Arabidopsis; D010840:Phytosterols; D043562:Receptors, G-Protein-Coupled; D013260:Steroids, Heterocyclic; D014157:Transcription Factors; C119828:cry protein, Drosophila; D010834:Phytochrome; D051939:Phytochrome B; D010544:Peroxidases; C108214:BAS1 protein, Arabidopsis; D054464:Peroxiredoxins; C023623:brassinolide