title: Expression of rolB in tobacco flowers affects the coordinated processes of anther dehiscence and style elongation.
abstract: The effect of auxin on stamen and pistil development in tobacco flowers was investigated by means of the localized expression of rolB (root loci B), an Agrobacterium oncogene that increases auxin sensitivity in a cell-autonomous fashion. When rolB is driven by the promoter of the meiosis-specific Arabidopsis gene DMC1 (disrupted meiotic cDNA 1), expression occurs earlier in male than in female developing organs, resulting in a delay in anther dehiscence with respect to normal timing of pistil development. As a consequence of this developmental uncoupling, self-pollination is prevented in pDMC1:rolB plants. Histological analysis of pDMC1:GFP plants indicates that in tobacco, this promoter is active not only in meiocytes but also in somatic tissues of the anther. In contrast, simultaneous expression of rolB in anther and pistil somatic tissues, achieved by expressing a construct containing rolB under the control of the promoter of the petunia gene FBP7 (floral binding protein 7), results in a concomitant delay of both anther dehiscence and pistil development without affecting self-pollination of the plants. Analysis of plants harboring the pFBP7:GUS construct shows that in tobacco, this promoter is active not only in the ovules, as described for petunia, but also in pistil and anther somatic tissues involved in the dehiscence program. The delay in anther dehiscence and pistil development could be phenocopied by exogenous application of auxin. Jasmonic acid (JA) could not rescue the delay in anther dehiscence. These results suggest that auxin plays a key role in the timing of anther dehiscence, the dehiscence program is controlled by the somatic tissues of the anther, and auxin also regulates pistil development.
authors.affiliation: Istituto Pasteur Fondazione Cenci Bolognetti, Dipartimento di Genetica e Biologia Molecolare, Università La Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Cecchetti
authors.forename: Mirella
authors.initials: M
authors.lastname: Pomponi
authors.forename: Maria Maddalena
authors.initials: MM
authors.lastname: Altamura
authors.forename: Mario
authors.initials: M
authors.lastname: Pezzotti
authors.forename: Sonia
authors.initials: S
authors.lastname: Marsilio
authors.forename: Simone
authors.initials: S
authors.lastname: D'Angeli
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Tornielli
authors.forename: Paolo
authors.initials: P
authors.lastname: Costantino
authors.forename: Maura
authors.initials: M
authors.lastname: Cardarelli
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics; D003517:Cyclopentanes / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics; D005298:Fertility / Q000235:genetics / Q000502:physiology; D035264:Flowers / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D049452:Green Fluorescent Proteins; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000494:pharmacology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D054883:Oxylipins; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011938:Rec A Recombinases; D014026:Nicotiana / Q000235:genetics* / Q000254:growth & development; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D001617:beta-Glucosidase / Q000235:genetics* / Q000502:physiology
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D003517:Cyclopentanes; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D007210:Indoleacetic Acids; D008164:Luminescent Proteins; D054883:Oxylipins; D010940:Plant Proteins; D014157:Transcription Factors; C097416:floral-binding protein 11, Petunia; D049452:Green Fluorescent Proteins; C011006:jasmonic acid; C513034:ATDMC1 protein, Arabidopsis; D011938:Rec A Recombinases; C092241:RolB protein, Agrobacterium rhizogenes; D001617:beta-Glucosidase