Three-dimensional reconstruction of anomalous chloroplasts in transgenic ipt tobacco.
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.
Synková
Helena
H
Academy of Sciences of the CR, Na Karlovce 1a, Institute of Experimental Botany, Praha, Czech Republic. synkova@ueb.cas.cz
Schnablová
Renáta
R
Polanská
Lenka
L
Husák
Michal
M
Siffel
Pavel
P
Vácha
Frantisek
F
Malbeck
Jirí
J
Machácková
Ivana
I
Nebesárová
Jana
J
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
D003583:Cytokinins; D019883:Alkyl and Aryl Transferases; C024274:adenylate isopentenyltransferase