title: The tobacco A-type cyclin, Nicta;CYCA3;2, at the nexus of cell division and differentiation.
abstract: Although most of the components of the cell cycle machinery are conserved in all eukaryotes, plants differ strikingly from animals by the absence of a homolog of E-type cyclin, an important regulator involved in G1/S-checkpoint control in animals. By contrast, plants contain a complex range of A-type cyclins, with no fewer than 10 members in Arabidopsis. We previously identified the tobacco A-type cyclin Nicta;CYCA3;2 as an early G1/S-activated gene. Here, we show that antisense expression of Nicta;CYCA3;2 in tobacco plants induces defects in embryo formation and impairs callus formation from leaf explants. The green fluorescent protein (GFP)-Nicta;CYCA3;2 fusion protein was localized in the nucleoplasm. Transgenic tobacco plants overproducing GFP-Nicta;CYCA3;2 could not be regenerated from leaf disc transformation, whereas some transgenic Arabidopsis plants were obtained by the floral-dip transformation method. Arabidopsis plants that overproduce GFP-Nicta;CYCA3;2 showed reduced cell differentiation and endoreplication and a dramatically modified morphology. Calli regenerated from leaf explants of these transgenic Arabidopsis plants were defective in shoot and root regeneration. We propose that Nicta;CYCA3;2 has important functions, analogous to those of cyclin E in animals, in the control of plant cell division and differentiation.
authors: Institut de Biologie Moléculaire des Plantes, Centre National de la Recherche Scientifique, Université Louis Pasteur de Strasbourg, 67084 Strasbourg, France.
authors: Yu
authors: Y
authors: Yu
authors: Andre
authors: A
authors: Steinmetz
authors: Denise
authors: D
authors: Meyer
authors: Spencer
authors: S
authors: Brown
authors: Wen-Hui
authors: WH
authors: Shen
mesh_terms: D016375:Antisense Elements (Genetics) / Q000235:genetics; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D002453:Cell Cycle / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D048429:Cell Size; D046508:Culture Techniques; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins; D006657:Histones / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D014026:Nicotiana / Q000166:cytology / Q000196:embryology / Q000235:genetics*
chemical_list: D016375:Antisense Elements (Genetics); D016213:Cyclins; D006657:Histones; D008164:Luminescent Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D018844:Cyclin-Dependent Kinases