title: Three-dimensional reconstruction of anomalous chloroplasts in transgenic ipt tobacco.
abstract: Anomalies in the ultrastructure of chloroplasts, from transgenic ipt tobacco, overproducing endogenous cytokinins (CKs) were studied. Detailed analyses of CKs and their metabolites showed that Pssu-ipt tobacco contained enhanced contents of CKs both in leaves and in isolated chloroplasts. The role of CKs in the formation of anomalous structures is suggested. Pssu-ipt chloroplasts frequently formed the distinct peripheral reticulum with a system of caverns that often involved mitochondria and/or peroxisomes. Large crystalloids, which were found in chloroplasts of Pssu-ipt, occupied up to 16% of chloroplast volume. We suggested that the crystalloids were formed by LHC II aggregates. This was supported by analysis of the fluorescence emission spectra at 77 degrees K, chlorophyll a/b ratio, immunogold staining of the structures, and crystallographic unit size analysis.
authors.affiliation: Academy of Sciences of the CR, Na Karlovce 1a, Institute of Experimental Botany, Praha, Czech Republic. synkova@ueb.cas.cz
authors.forename: Helena
authors.initials: H
authors.lastname: Synková
authors.forename: Renáta
authors.initials: R
authors.lastname: Schnablová
authors.forename: Lenka
authors.initials: L
authors.lastname: Polanská
authors.forename: Michal
authors.initials: M
authors.lastname: Husák
authors.forename: Pavel
authors.initials: P
authors.lastname: Siffel
authors.forename: Frantisek
authors.initials: F
authors.lastname: Vácha
authors.forename: Jirí
authors.initials: J
authors.lastname: Malbeck
authors.forename: Ivana
authors.initials: I
authors.lastname: Machácková
authors.forename: Jana
authors.initials: J
authors.lastname: Nebesárová
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D003583:Cytokinins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D030821:Plants, Genetically Modified; D014026:Nicotiana / Q000166:cytology* / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D019076:Transgenes / Q000235:genetics
chemical_list: D003583:Cytokinins; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase