Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Georgia scientists plot key events in plants’ evolution

08.04.2003


Since Charles Darwin heralded evolution more than 150 years ago, scientists have sought to better understand when and how the vast variety of plants today diverged from common ancestors.



A new University of Georgia study, just published in Nature, demonstrates key events in plant evolution. It allows scientists to infer what the gene order may have looked like in a common ancestor of higher plants. And it shows one way plants may have differentiated from their ancestors and each other.

"By studying the completed sequence of the smallest flowering plant, Arabidopsis, we showed that most of its genes were duplicated about 200 million years ago and duplicated again about 80 million years ago," said Andrew Paterson, a UGA plant geneticist and director of the study. "The ensuing loss of ’extra genes’ caused many of the differences among modern plants."


Two years ago, scientists finished the genetic sequencing of Arabidopsis, a small, weedy plant. It was a major event, the first plant to be completely sequenced. Arabidopsis had been chosen with the assumption that it would be fairly easy, since it was small. Sometimes small packages aren’t so simple.

Seeded throughout its five chromosomes were thousands of genes that seemed to be "junk." When UGA scientists compared all of the genes, they found evidence of duplicated "blocks" of similar sets of genes in two, four or eight different places along the chromosomes.

It’s well known that many plants contain two or more copies of most genes. But why these copies exist and when they occurred has been unknown. Their surprising abundance in the tiny, well-studied Arabidopsis indicates that genome duplications may have played a bigger evolutionary role than was previously thought.

Why were these blocks of genes duplicated? When did this happen? Answering these questions involved a lot of computerized comparing and contrasting.

The scientists repeatedly compared related pairs of Arabidopsis genes with genes from other plants to figure out which genes had been "hanging out with each other," said UGA graduate student Brad Chapman, who coauthored the study, along with John Bowers, Junkang Rong and Paterson. "Genomes with similar blocks of duplication, ’spelled’ in similar ways, had been hanging out together for longer periods of time," Chapman said.

"We tested many, many combinations," Paterson said. "We tested Arabidopsis with cotton, cauliflower, alfalfa, soybeans, tomatoes, rice, pine trees and moss."

After more than 22,000 such comparisons, the results were pooled, and the scientists looked for breakpoints. The breakpoints indicate duplication events, Paterson said. And the study shows that Arabidopsis has duplicated at least twice, and perhaps a third time.

Each time a duplication event occurred, the entire genetic sequence of Arabidopsis doubled. The plant lived on with spare copies of all of its genetic material. And over time, the "extra genes" were shuffled around or lost. It is suspected that this may be one explanation for how different species emerged.

"The duplication event that occurred 200 million years ago occurred in virtually all plants," Paterson said. "The duplication event 80 million years ago affected a lot of plants, but not as many."

The study is attracting attention in the scientific community, because it combines an evolutionary approach with genomic data to learn more about the natural world.

This information will have a significant economic impact because it permits scientists to make better use of the Arabidopsis sequence. It will allow them to study and improve other plants whose DNA hasn’t yet been completely sequenced, such as peanuts, cotton or wheat, saving both time and money.

"For example, we can take the 2,000 genes known on the cotton map, compare them with the Arabidopsis sequence and, with this analysis, make good, educated guesses about where the other 48,000 cotton genes are," Paterson said.

Kim Carlyle | EurekAlert!
Further information:
http://www.uga.edu/

More articles from Life Sciences:

nachricht Turning carbon dioxide into liquid fuel
06.08.2020 | DOE/Argonne National Laboratory

nachricht Tellurium makes the difference
06.08.2020 | Friedrich-Schiller-Universität Jena

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: ScanCut project completed: laser cutting enables more intricate plug connector designs

Scientists at the Fraunhofer Institute for Laser Technology ILT have come up with a striking new addition to contact stamping technologies in the ERDF research project ScanCut. In collaboration with industry partners from North Rhine-Westphalia, the Aachen-based team of researchers developed a hybrid manufacturing process for the laser cutting of thin-walled metal strips. This new process makes it possible to fabricate even the tiniest details of contact parts in an eco-friendly, high-precision and efficient manner.

Plug connectors are tiny and, at first glance, unremarkable – yet modern vehicles would be unable to function without them. Several thousand plug connectors...

Im Focus: New Strategy Against Osteoporosis

An international research team has found a new approach that may be able to reduce bone loss in osteoporosis and maintain bone health.

Osteoporosis is the most common age-related bone disease which affects hundreds of millions of individuals worldwide. It is estimated that one in three women...

Im Focus: AI & single-cell genomics

New software predicts cell fate

Traditional single-cell sequencing methods help to reveal insights about cellular differences and functions - but they do this with static snapshots only...

Im Focus: TU Graz Researchers synthesize nanoparticles tailored for special applications

“Core-shell” clusters pave the way for new efficient nanomaterials that make catalysts, magnetic and laser sensors or measuring devices for detecting electromagnetic radiation more efficient.

Whether in innovative high-tech materials, more powerful computer chips, pharmaceuticals or in the field of renewable energies, nanoparticles – smallest...

Im Focus: Tailored light inspired by nature

An international research team with Prof. Cornelia Denz from the Institute of Applied Physics at the University of Münster develop for the first time light fields using caustics that do not change during propagation. With the new method, the physicists cleverly exploit light structures that can be seen in rainbows or when light is transmitted through drinking glasses.

Modern applications as high resolution microsopy or micro- or nanoscale material processing require customized laser beams that do not change during...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“Conference on Laser Polishing – LaP 2020”: The final touches for surfaces

23.07.2020 | Event News

Conference radar for cybersecurity

21.07.2020 | Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

 
Latest News

Rare Earth Elements in Norwegian Fjords?

06.08.2020 | Earth Sciences

Anode material for safe batteries with a long cycle life

06.08.2020 | Power and Electrical Engineering

Turning carbon dioxide into liquid fuel

06.08.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>