The plastid and mitochondrial genomes of Eucalyptus grandis
Desre Pinard, Alexander A. Myburg and Eshchar Mizrachi
plant organellar genomes have significant impact on metabolism and
adaptation, and as such, accurate assembly and annotation of plant
organellar genomes is an important tool in understanding the
evolutionary history and interactions between these genomes.
Intracellular DNA transfer is ongoing between the nuclear and organellar
genomes, and can lead to significant genomic variation between, and
within, species that impacts downstream analysis of genomes and
In order to facilitate further studies of cytonuclear interactions in Eucalyptus, we report an updated annotation of the E. grandis plastid genome, and the second sequenced and annotated mitochondrial genome of the Myrtales, that of E. grandis.
The 478,813 bp mitochondrial genome shows the conserved protein coding
regions and gene order rearrangements typical of land plants. There have
been widespread insertions of organellar DNA into the E. grandis nuclear
genome, which span 141 annotated nuclear genes. Further, we identify
predicted editing sites to allow for the discrimination of
RNA-sequencing reads between nuclear and organellar gene copies, finding
that nuclear copies of organellar genes are not expressed in E. grandis.
implications of organellar DNA transfer to the nucleus are often
ignored, despite the insight they can give into the ongoing evolution of
plant genomes, and the problems they can cause in many applications of
genomics. Future comparisons of the transcription and regulation of
organellar genes between Eucalyptus genotypes may provide insight
to the cytonuclear interactions that impact economically important
traits in this widely grown lignocellulosic crop species.
Source: BMC Genomics