Gene expression in plant mitochondria: transcriptional and post–transcriptional control

The informational content of the mitochondrial genome in plants is, although small, essential for each cell. Gene expression in these organelles involves a number of distinct transcriptional and post–transcriptional steps. The complex post–transcriptional processes of plant mitochondria such as 5′ and 3′ RNA processing, intron splicing, RNA editing and controlled RNA stability extensively modify individual steady–state RNA levels and influence the mRNA quantities available for translation. In this overview of the processes in mitochondrial gene expression, we focus on confirmed and potential sites of regulatory interference and discuss the evolutionary origins of the transcriptional and post–transcriptional processes.