Date of this Version
Spring 2016 Research Fair poster, University of Nebraska-Lincoln.
In addition to containing a large and complex mitochondrial genome, the mitochondria of several species of plants have been shown to contain an independent, self-replicating DNA molecule in the form of a plasmid. Plants in the Brassica genus contain a linear plasmid that is approximately 11.6 kilobases in length. The plasmid is characterized by the presence of terminal inverted repeats and covalently bonded proteins at its termini (Handa 2008). The plasmid also contains six ORFs that encode DNA and RNA polymerases and a number of unknown proteins (Figure 1). Currently, both the function of this plasmid and the mechanisms by which it is transported into and replicated within the mitochondria are largely unknown. Our current hypothesis is that these mitochondrial plasmids were originally acquired as a virus by a subspecies of Brassica and have since become an integrated component of the plant’s mitochondrial machinery. During the course of our research, we hope to discern the genetic basis and overall nature of the Brassica mitochondrial plasmid, as well as develop practical methods for targeting specific gene sequences and protein products into the mitochondria through the use of this plasmid.