title: Separable whorl-specific expression and negative regulation by enhancer elements within the AGAMOUS second intron.
abstract: We analyzed the 4-kb intragenic control region of the AGAMOUS (AG) gene to gain insight into the mechanisms controlling its expression during early flower development. We identified three major expression patterns conferred by 19 AG::reporter gene constructs: the normal AG pattern, a stamen-specific pattern, and a predominantly carpel pattern. To determine whether these three expression patterns were under negative control by APETALA2 (AP2) or LEUNIG (LUG), we analyzed beta-glucuronidase staining patterns in Arabidopsis plants homozygous for strong ap2 and lug mutations. Our results indicated that the stamen-specific pattern was independent of AP2 but dependent on LUG; conversely, the carpel-specific pattern was independent of LUG but dependent on AP2. These results lead to a model of control of AG expression such that expression in each of the two inner whorls is under independent positive and negative control.
authors.affiliation: Biology Department, McGill University, Montreal, Quebec, Canada H3A 1B1.
authors.forename: M K
authors.initials: MK
authors.lastname: Deyholos
authors.forename: L E
authors.initials: LE
authors.lastname: Sieburth
mesh_terms: D026342:AGAMOUS Protein, Arabidopsis; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D018506:Gene Expression Regulation, Plant; D005966:Glucuronidase / Q000235:genetics; D018398:Homeodomain Proteins / Q000378:metabolism; D006720:Homozygote; D007438:Introns; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D030821:Plants, Genetically Modified
chemical_list: D026342:AGAMOUS Protein, Arabidopsis; C499534:APETALA2 protein, Arabidopsis; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D005966:Glucuronidase