Chloroplast Genome (Plastome)
Definition
A circular, 120-160 kb genome inside plant chloroplasts, present in hundreds of copies per cell. Its high copy number makes it recoverable from degraded material where nuclear DNA has been lost.
- Size
- 120 to 160 kb
- Shape
- Circular
- Copy number
- Hundreds per cell
- Forensic advantage
- Recoverable from degraded plant material
Common questions
Why is the plastome useful when nuclear plant DNA has degraded?+
Its high copy number per cell means far more template molecules survive degradation than for single-copy or low-copy nuclear genes, so PCR amplification succeeds on samples too degraded for nuclear DNA barcoding, such as aged trace plant material at a scene.
What forensic identification does the plastome support beyond species identification?+
Regions of the plastome, along with nuclear barcodes, help identify plant species and family, which is used in cases involving trace botanical evidence, illegal timber, or plant-based drug material, though it is generally less variable than nuclear markers for individual or population-level distinction.
Related terms
- BOLD
- Barcode of Life Data System, an international curated database linking COI sequences to verified voucher specimens with collection locality and taxonomic annotation....
- DNA Barcoding
- Species identification using a short, standardised region of the mitochondrial genome. For animals, the primary barcode marker is a 648-base-pair segment of...
- matK
- Maturase K gene, located in the chloroplast trnK intron. The second CBOL-approved plant barcode marker, with an approximately 870 bp diagnostic amplicon....
- rbcL
- A chloroplast gene encoding the large subunit of RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase). One of the two CBOL-standardized plant barcode loci. Widely amplifiable but...
- Species Resolution Rate
- The proportion of species-level queries for which the barcoding approach returns an unambiguous species identification rather than only a genus or family...