Summary: Transients in chloroplast gene transcription
Sujith Puthiyaveetil, John F. Allen *
School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
Received 21 January 2008
Available online 12 February 2008
Transcriptional regulation of chloroplast genes is demonstrated by Quantitative Polymerase Chain Reaction (qPCR). These genes
encode apoproteins of the reaction centres of photosystem I and photosystem II. Their transcription is regulated by changes in wave-
length of light selectively absorbed by photosystem I and photosystem II, and therefore by the redox state of an electron carrier located
between the two photosystems. Chloroplast transcriptional redox regulation is shown to have greater amplitude, and the kinetics of tran-
scriptional changes are more complex, than suggested by previous experiments using only DNA probes in Northern blot experiments.
Redox effects on chloroplast transcription appear to be superimposed on an endogenous rhythm of mRNA abundance. The functional
significance of these transients in chloroplast gene transcription is discussed.
Ó 2008 Elsevier Inc. All rights reserved.
Keywords: Photosynthesis; Redox control; Plastoquinone; Plastid genome; Gene expression; Electron transport
Regulation at the level of transcription of DNA to RNA
has long been recognized as a principal mechanism for
modulating gene expression in biological systems .
Eukaryotic plants and algae contain chloroplasts, which
perform photosynthesis  and also contain a functional