title: Aryl hydrocarbon receptor (AhR)-mediated reporter gene expression systems in transgenic tobacco plants.
abstract: In mammals, the aryl hydrocarbon receptor (AhR) mediates expression of certain genes, including CYP1A1, in response to exposure to dioxins and related compounds. We have constructed a mouse AhR-mediated gene expression systems for a beta-glucuronidase (GUS) reporter gene consisting of an AhR, an AhR nuclear translocator (Arnt), and a xenobiotic response element (XRE)-driven promoter in transgenic tobacco plants. On treatment with the AhR ligands 3-methylcholanthrene (MC), beta-naphthoflavone (betaNF), and indigo, the transgenic tobacco plants exhibited enhanced GUS activity, presumably by inducible expression of the reporter gene. The recombinant AhR (AhRV), with the activation domain replaced by that of the Herpes simplex virus protein VP16, induced GUS activity much more than the wild-type AhR in the transgenic tobacco plants. Plants carrying AhRV expressed the GUS reporter gene in a dose- and time-dependent manner when treated with MC; GUS activity was detected at 5 nM MC on solid medium and at 12 h after soaking in 25 microM MC. Histochemical GUS staining showed that this system was active mainly in leaf and stem. These results suggest that the AhR-mediated reporter gene expression system has potential for the bioassay of dioxins in the environment and as a novel gene expression system in plants.
authors: Graduate School of Science and Technology, Kobe University, Kobe, Hyogo, Japan.
authors: Susumu
authors: S
authors: Kodama
authors: Kumiko
authors: K
authors: Okada
authors: Hideyuki
authors: H
authors: Inui
authors: Hideo
authors: H
authors: Ohkawa
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D015870:Gene Expression / Q000187:drug effects; D005966:Glucuronidase / Q000235:genetics* / Q000378:metabolism; D007203:Indigo Carmine; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology; D008748:Methylcholanthrene / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D015394:Molecular Structure; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics* / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D005966:Glucuronidase; D007203:Indigo Carmine; D007211:Indoles; D008748:Methylcholanthrene; D018336:Receptors, Aryl Hydrocarbon; C484722:Ahr protein, mouse