Kudzu, flowering plant

Agricultural Research Service\Peggy Grebb

Researchers have found a section of plant DNA that could be used as the universal 'barcode' to identify flowering plants, aiding biodiversity research.

They also hope it can be used to track endangered plant species and check whether they are being transported illegally.

The research team, led by Vincent Savolainen of the UK's Imperial College London and Royal Botanic Gardens, Kew, published their findings this week (4 February) in the Proceedings of the National Academy of Sciences.

While DNA barcoding — the use of a particular region of DNA to distinguish between species — is already established in animals, no single, universal section of DNA has yet been found for flowering plants.

Various DNA segments have been mooted. Savolainen and colleagues tested eight of these segments on over 1,600 plant specimens, mainly orchids from Costa Rica and other plants from the Kruger National Park in South Africa — sites chosen for their exceptional biodiversity.

They found that a specific section of a gene, matK, was easy to use and had a suitable 'barcoding gap' — it is different enough between species and similar enough within species to make identifications.

"In the future we'd like to see this idea of reading plants' genetic barcodes translated into a portable device that can be taken into any environment, which can quickly and easily analyse any plant sample's matK DNA and compare it to a vast database of information, allowing almost instantaneous identification," said Savolainen in a press statement.

Eldredge Bermingham, senior scientist at the Smithsonian Tropical Research Institute in Panama, is keen to see the scientific community adopt a barcode for plants.

"Plants are lagging far behind animals in DNA barcoding, simply because there's been no consensus reached. If [the community] decide on matK, it will enhance the botanical field and help it catch up."

This will particularly benefit developing countries with an interest in identifying their natural heritage with DNA sequences, Bermingham told SciDev.Net.

Bermingham says that since DNA sequencing techniques have become so widespread, a new one can easily be applied, even if matK turns out to be the wrong barcode. Scientists are already building up collections of plants and their DNA.

But he points out that, in this study, matK was only used to identify "relatively undiverse" plants.

"We need to know whether matK does a good job when you start applying it to the vast tropical diversity — I think that's an open question at the moment."