title: Inactivation of the phloem-specific Dof zinc finger gene DAG1 affects response to light and integrity of the testa of Arabidopsis seeds.
abstract: We show here that seeds from the knockout mutant of the Arabidopsis DAG1 gene encoding a Dof zinc finger transcription factor have an altered response to red and far-red light. Mutant dag1 seeds are induced to germinate by much lower red light fluence rates, and germination reaches more quickly a point where it is independent of phytochrome signaling. Moreover, although microscopic analysis reveals no obvious structural alterations in the seed coat (testa) of dag1 seeds, staining assays with different dyes point to an abnormal fragility of the testa. By extensive in situ mRNA hybridization analysis we show here that the gene, which is not expressed in the embryo, is specifically expressed in the phloem of all organs of the mother plant.
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: Maura
authors.initials: M
authors.lastname: Papi
authors.forename: Sabrina
authors.initials: S
authors.lastname: Sabatini
authors.forename: Maria Maddalena
authors.initials: MM
authors.lastname: Altamura
authors.forename: Lars
authors.initials: L
authors.lastname: Hennig
authors.forename: Eberhard
authors.initials: E
authors.lastname: Schäfer
authors.forename: Paolo
authors.initials: P
authors.lastname: Costantino
authors.forename: Paola
authors.initials: P
authors.lastname: Vittorioso
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029681:Arabidopsis Proteins; D001692:Biological Transport / Q000528:radiation effects; D004268:DNA-Binding Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D018525:Germination / Q000235:genetics / Q000528:radiation effects; D017403:In Situ Hybridization; D008027:Light; D009154:Mutation; D010834:Phytochrome / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; C102164:DAG protein, Antirrhinum majus; C407526:DAG1 protein, Arabidopsis; D004268:DNA-Binding Proteins; C095941:Dof3 protein, Arabidopsis; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; D010834:Phytochrome