title: Genetic interactions between brassinosteroid-inactivating P450s and photomorphogenic photoreceptors in Arabidopsis thaliana.
abstract: Plants use light as a source of information via a suite of photomorphogenic photoreceptors to optimize growth in response to their light environment. Growth-promoting hormones such as brassinosteroids also can modulate many of these responses. BAS1 and SOB7 are brassinosteroid-catabolizing P450s in Arabidopsis thaliana that synergistically/redundantly modulate photomorphogenic traits such as flowering time. The role of BAS1 and SOB7 in photomorphogenesis has been investigated by studying null-mutant genetic interactions with the photoreceptors phyA, phyB, and cry1 with regard to seed germination and flowering time. The removal of BAS1 and/or SOB7 rescued the low germination rate of the phyA-211 phyB-9 double-null mutant. With regard to floral induction, bas1-2 and sob7-1 showed a complex set of genetic interactions with photoreceptor-null mutants. Histochemical analysis of transgenic plants harboring BAS1:BAS1-GUS and SOB7:SOB7-GUS translational fusions under the control of their endogenous promoters revealed overlapping and distinct expression patterns. BAS1's expression in the shoot apex increases during the phase transition from short-to-long-day growth conditions and requires phyB in red light. In summary, BAS1 and SOB7 displayed both simple and complex genetic interactions with the phytochromes in a plant-stage specific manner.
authors.affiliation: Department of Crop and Soil Sciences, Washington State University, Pullman, Washington 99164, USA.
authors.forename: Kulbir Singh
authors.initials: KS
authors.lastname: Sandhu
authors.forename: Katherine
authors.initials: K
authors.lastname: Hagely
authors.forename: Michael M
authors.initials: MM
authors.lastname: Neff
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060406:Brassinosteroids / Q000378:metabolism*; D056931:Cryptochromes / Q000235:genetics / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D035264:Flowers / Q000235:genetics; D017343:Genes, Plant; D018525:Germination / Q000235:genetics; D054464:Peroxiredoxins / Q000235:genetics* / Q000378:metabolism; D055519:Photoreceptors, Plant / Q000235:genetics* / Q000378:metabolism; D051942:Phytochrome A / Q000235:genetics / Q000378:metabolism; D051939:Phytochrome B / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D029681:Arabidopsis Proteins; D060406:Brassinosteroids; C538962:CRY1 protein, Arabidopsis; D056931:Cryptochromes; C497973:PHYA protein, Arabidopsis; C497952:PHYB protein, Arabidopsis; D055519:Photoreceptors, Plant; D051942:Phytochrome A; D051939:Phytochrome B; D003577:Cytochrome P-450 Enzyme System; C500888:CYP72C1 protein, Arabidopsis; C108214:BAS1 protein, Arabidopsis; D054464:Peroxiredoxins
keywords: CYP72C1; CYP734A1; cryptochrome 1; phytochrome A; phytochrome B