Abstract
Since mitochondrial DNA contains many genes encoding the components of an oxidative phosphorylation system, transcription of mitochondrial genes and its regulation are very important when maintaining the metabolism of plant cells.
Many mitochondrial genes in higher plants are transcribed monocistronically but some genes are co-transcribed. These transcripts become mature and functional RNAs through the post-transcriptional processing reactions such as intron splicing, RNA editing and 5' and 3' processing. CRTAAGAGA (CNM) motif and CGTATATAA (TA) element were reported as a core promoter of a dicotyledonous plant. We found CNM motif in 5' upstream of some genes of tobacco mitochondria but the experimental proof has not been done. Then, analysis of the transcription is advanced by 5'-RACE and the circularized RT-PCR methods, and transcription start sites of some kinds of structural genes and rRNA genes were determined and CNM, CNM-like motif, and TA and TA-like element were found.
