A role for brassinosteroids in light-dependent development of Arabidopsis.
Although steroid hormones are important for animal development, the physiological role of plant steroids is unknown. The Arabidopsis DET2 gene encodes a protein that shares significant sequence identity with mammalian steroid 5 alpha-reductases. A mutation of glutamate 204, which is absolutely required for the activity of human steroid reductase, abolishes the in vivo activity of DET2 and leads to defects in light-regulated development that can be ameliorated by application of a plant steroid, brassinolide. Thus, DET2 may encode a reductase in the brassinolide biosynthetic pathway, and brassinosteroids may constitute a distinct class of phytohormones with an important role in light-regulated development of higher plants.
Li
J
J
Plant Biology Laboratory, Salk Institute, La Jolla, CA 92037, USA.
Nagpal
P
P
Vitart
V
V
McMorris
T C
TC
Chory
J
J
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols / Q000378:metabolism* / Q000494:pharmacology; D002874:Chromosome Mapping; D017343:Genes, Plant; D006801:Humans; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D010641:Phenotype; D010937:Plant Growth Regulators / Q000096:biosynthesis / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics*; D051381:Rats; D016415:Sequence Alignment; D015398:Signal Transduction; D013260:Steroids, Heterocyclic / Q000378:metabolism* / Q000494:pharmacology
D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D002777:Cholestanols; C098907:DET2 protein, Arabidopsis; D010937:Plant Growth Regulators; D010940:Plant Proteins; D013260:Steroids, Heterocyclic; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase; C023623:brassinolide