title: ABI3 affects plastid differentiation in dark-grown Arabidopsis seedlings.
abstract: The Arabidopsis ABSCISIC ACID-INSENSITIVE3 (ABI3) protein has been identified previously as a crucial regulator of late seed development. Here, we show that dark-grown abi3 plants, or abi3 plants returned to the dark after germination in the light, developed and maintained an etioplast with a prominent prolamellar body at developmental stages in which the wild type did not. Overexpression of ABI3 led to the preservation of the plastid ultrastructure that was present at the onset of darkness. These observations suggest that ABI3 plays a role in plastid differentiation pathways in vegetative tissues. Furthermore, the analysis of deetiolated (det1) abi3 double mutants revealed that DET1 and ABI3 impinge on a multitude of common processes. During seed maturation, ABI3 required DET1 to achieve its full expression. Mature det1 abi3 seeds were found to be in a highly germinative state, indicating that germination is controlled by both DET1 and ABI3. During plastid differentiation in leaves of dark-grown plants, DET1 is required for the action of ABI3 as it is during seed development. Together, the results suggest that ABI3 is at least partly regulated by light.
authors.affiliation: Vakgroep Moleculaire Genetica, Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Rohde
authors.forename: R
authors.initials: R
authors.lastname: De Rycke
authors.forename: T
authors.initials: T
authors.lastname: Beeckman
authors.forename: G
authors.initials: G
authors.lastname: Engler
authors.forename: M
authors.initials: M
authors.lastname: Van Montagu
authors.forename: W
authors.initials: W
authors.lastname: Boerjan
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000528:radiation effects; D029681:Arabidopsis Proteins; D003624:Darkness; D017343:Genes, Plant; D018525:Germination; D047908:Intracellular Signaling Peptides and Proteins; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D010641:Phenotype; D063245:Plant Development; D010940:Plant Proteins / Q000235:genetics*; D010944:Plants / Q000235:genetics / Q000528:radiation effects; D018087:Plastids / Q000235:genetics; D014157:Transcription Factors
chemical_list: C091601:ABI3 protein, Arabidopsis; D029681:Arabidopsis Proteins; C088435:DET1 protein, Arabidopsis; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D014157:Transcription Factors