title: PEG-mediated plastid transformation: a new system for transient gene expression assays in chloroplasts.
abstract: Evidence is presented for the introduction of functional copies of the GUS-reporter gene with plastid regulatory signals into chloroplasts after treatment of Nicotiana plumbaginifolia leaf protoplasts with PEG. GUS-activity is found in cells derived from protoplasts treated with PEG in the presence of plasmids harbouring the GUS-gene under the control of plastid promoter and terminator signals (plastid-specific reporter gene constructions). The activity is maintained after chloroplast isolation and incubation with the protease thermolysin under conditions sufficient to completely remove the much higher transient nuclear/cytoplasmic expression of a GUS-gene carrying the CaMV 35S-promoter. Likewise, GUS-activity derived from a plasmid coding for the nuclear/cytoplasmic expression of the reporter gene with a plastid transit presequence is also maintained after these procedures. These results indicate that PEG-treatment is a suitable protocol by which to introduce DNA into chloroplasts for the study of transient gene expression.
authors.affiliation: Laboratory for Cell Biology and Cell Culture, University of Munich, Institute of Botany, Menzinger Str. 67, W-8000, Munich 19, Federal Republic of Germany.
authors.forename: B
authors.initials: B
authors.lastname: Spörlein
authors.forename: M
authors.initials: M
authors.lastname: Streubel
authors.forename: G
authors.initials: G
authors.lastname: Dahlfeld
authors.forename: P
authors.initials: P
authors.lastname: Westhoff
authors.forename: H U
authors.initials: HU
authors.lastname: Koop