title: Three redundant brassinosteroid early response genes encode putative bHLH transcription factors required for normal growth.
abstract: Brassinosteroids (BRs) are a class of polyhydroxylated steroids that are important regulators of plant growth and development. We have identified three closely related basic helix-loop-helix (bHLH) transcription factors, BEE1, BEE2, and BEE3, as products of early response genes required for full BR response. Comparison of the phenotypes of plants that overexpress BEE1 with bee1 bee2 bee3 triple-knockout mutant plants suggests that BEE1, BEE2, and BEE3 are functionally redundant positive regulators of BR signaling. Expression of BEE1, BEE2, and BEE3 is also regulated by other hormones, notably abscisic acid (ABA), a known antagonist of BR signaling. Reduced ABA response in plants overexpressing BEE1 suggests that BEE proteins may function as signaling intermediates in multiple pathways.
authors.affiliation: Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
authors.forename: Danielle M
authors.initials: DM
authors.lastname: Friedrichsen
authors.forename: Jennifer
authors.initials: J
authors.lastname: Nemhauser
authors.forename: Takamichi
authors.initials: T
authors.lastname: Muramitsu
authors.forename: Julin N
authors.initials: JN
authors.lastname: Maloof
authors.forename: José
authors.initials: J
authors.lastname: Alonso
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Ecker
authors.forename: Masaki
authors.initials: M
authors.lastname: Furuya
authors.forename: Joanne
authors.initials: J
authors.lastname: Chory
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D060406:Brassinosteroids; D002777:Cholestanols / Q000494:pharmacology; D018257:Helix-Loop-Helix Motifs; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D013256:Steroids / Q000378:metabolism*; D013260:Steroids, Heterocyclic / Q000494:pharmacology; D014157:Transcription Factors / Q000187:drug effects / Q000235:genetics*
chemical_list: D060406:Brassinosteroids; D002777:Cholestanols; D010937:Plant Growth Regulators; D013256:Steroids; D013260:Steroids, Heterocyclic; D014157:Transcription Factors; D000040:Abscisic Acid; C023623:brassinolide