title: Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis.
abstract: Jasmonates induce plant-defence responses and act to regulate defence-related genes including positive feedback of the lipoxygenase 2 (LOX2) gene involved in jasmonate synthesis. To identify jasmonate-signalling mutants, we used a fusion genetic strategy in which the firefly luciferase (FLUC) and Escherichia coli beta-glucuronidase (GUS) reporters were expressed under control of the jasmonate-responsive LOX2 promoter. Spatial and temporal patterns of reporter expression were determined initially, and revealed that JA-responsive expression from the LOX2 promoter required de novo protein synthesis. Reporter activity was also induced by the protein kinase inhibitor staurosporine and antagonized by the protein phosphatase inhibitor okadaic acid. FLUC bio-imaging, RNA gel-blot analysis and progeny analyses identified three recessive mutants that underexpress the FLUC reporter, designated jue1, 2 and 3, as well as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition, reporter induction and endogenous LOX2 expression by staurosporine was absent in joe2.
authors.affiliation: Institute of Molecular Biology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen K, Denmark.
authors.forename: Anders B
authors.initials: AB
authors.lastname: Jensen
authors.forename: Dora
authors.initials: D
authors.lastname: Raventos
authors.forename: John
authors.initials: J
authors.lastname: Mundy
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008084:Lipoxygenase / Q000235:genetics*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008163:Luminescent Measurements; D009154:Mutation; D019319:Okadaic Acid / Q000494:pharmacology; D054883:Oxylipins; D010641:Phenotype; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000235:genetics; D010937:Plant Growth Regulators / Q000494:pharmacology*; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D029681:Arabidopsis Proteins; C112279:COI1 protein, Arabidopsis; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D019319:Okadaic Acid; C011006:jasmonic acid; D008084:Lipoxygenase; D008156:Luciferases; D011494:Protein Kinases; D010744:Phosphoric Monoester Hydrolases; D005966:Glucuronidase; D019311:Staurosporine