title: Restoration of stamen development and production of functional pollen in an alloplasmic CMS tobacco line by ectopic expression of the Arabidopsis thaliana SUPERMAN gene.
abstract: The alloplasmic male-sterile tobacco line Nta(rep)S, combining the nucleus of Nicotiana tabacum with the cytoplasm of Nicotiana repanda, exhibits cadastral-type anomalies due to a fusion of several stamens with the pistil. These anomalies share similarities with Arabidopsis superman mutants. SUPERMAN (SUP) is a cadastral gene controlling the boundary between whorls 3 (androecium) and 4 (gynoecium). Thus we hypothesized that the expression of the tobacco SUP orthologue might be impaired in the alloplasmic Nta(rep)S line, and that the deficiency could be complemented by the Arabidopsis SUP gene. Here we show that the ectopic expression of SUP in the alloplasmic male-sterile tobacco line Nta(rep)S significantly increases the frequency of flowers possessing free stamens, inducing the recovery of a proper structure for whorls 3 and 4. Furthermore, flowers of transgenic plants show a significant improvement of the morphology of stamens, and more particularly of the anthers, which are able to produce few but functional pollen. The data show that ectopic expression of Arabidopsis SUP reactivates the regulatory cascade of anther development. The plausible causes of the developmental defects of anthers in the alloplasmic male-sterile tobacco line are discussed in relation to the model of regulation of the Arabidopsis SUP gene.
authors.affiliation: Laboratoire de Biologie Cellulaire et Biotechnologie Végétale, Institut Biologie Végétale Moléculaire, UMR 0619: Université Bordeaux 2-INRA, CR-INRA Bordeaux, BP81, 33883 Villenave d'Ornon Cedex, France.
authors.forename: Agnès
authors.initials: A
authors.lastname: Bereterbide
authors.forename: Michel
authors.initials: M
authors.lastname: Hernould
authors.forename: Isabelle
authors.initials: I
authors.lastname: Farbos
authors.forename: Kristina
authors.initials: K
authors.lastname: Glimelius
authors.forename: Armand
authors.initials: A
authors.lastname: Mouras
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins; D005298:Fertility / Q000502:physiology; D020869:Gene Expression Profiling; D017403:In Situ Hybridization; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics; D018547:Plant Stems / Q000254:growth & development* / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D011058:Pollen / Q000254:growth & development* / Q000648:ultrastructure; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D014157:Transcription Factors; C096661:superman protein, Arabidopsis