Is transcription of higher plant chloroplast ribosomal operons regulated by premature termination?

Abstract
Three stem‐loop structures (H1, H2, H3) can be formed in the leader transcript of the chloroplast rDNA of spinach, tobacco and maize. H2 and H3 partially overlap and cannot exist simultaneously. These potential hairpins lead us to postulate that higher plant chloroplast rDNA is regulated by premature termination. This mechanism could be controlled by the presence or absence of a ribosome translating an hypothetical leader peptide encoded in the rDNA leader sequence of these 3 higher plants.