Navigation Links
UT Knoxville professor finds unexpected key to flowering plants' diversity
Date:7/28/2008

KNOXVILLE -- What began with an off-the-cuff curiosity eventually led Joe Williams to hang from the limbs of a tree 80 feet above the soil of northeastern Australia.

The things Williams, a University of Tennessee, Knoxville, researcher found there may help explain the amazing diversity in the world's flowering plants, a question that has puzzled scientists from the time of Charles Darwin to today.

Williams' findings, published online this week by the Proceedings of the National Academy of Sciences, show that the ability of flowering plants -- known as angiosperms -- to quickly and efficiently move sperm from pollen to egg through a part of the plant was the key to their evolutionary diversity.

His curiosity was based in the time it takes from when pollen lands on a plant to the time that its' seed is fertilized. Williams noticed a recurring theme in the research papers he read:

"They would usually describe how fertilization was occurring, but they never tell you much about timing," said Williams, an assistant professor of ecology and evolutionary biology at UT Knoxville.

For a seeded plant to fertilize, pollen that lands on the flower must grow a tube to carry sperm to the egg. In non-flowering plants, the pathway is usually short, because the pollen tube must destroy cells in its path, which is a time-consuming process. In flowering plants, though, pollen tubes are able to cover longer distances to the egg by essentially "squeezing" between cells. It is a trait that Williams says is vital to their diversification.

"The longer a plant takes to fertilize, for the pollen to reach the egg," said Williams, "the more chance there is for it to die."

When he studied the data he had collected through the years, Williams found that older lineages of flowering plants -- those on lower branches of the angiosperms' evolutionary family tree -- grew shorter tubes of pollen than those that went on to evolve into the diverse array of flowering plants that exist today.

That's what brought Williams to a harness in the rainforest of Australia. To confirm what he found in the data analysis, he pollinated -- by hand -- an ancient vine known as Austrobaileya that grows high in the canopy. He chose that plant, along with another plant found only on the Pacific island of New Caledonia and a water lily that grows high in the Colorado mountains, to test because they developed as species early in flowering plants' evolution.

He found that, when compared to more recently evolved species of angiosperms, the older plants grew shorter pollen tubes and took longer to do so than more diverse modern species. According to Williams, this indicates that these pollen tubes likely played a previously unknown role in spurring the evolution of the roughly 250,000 species of flowering plants we see today.

"As these plants gained the ability to grow pollen tubes faster and over longer distances," said Williams, "It gave them the ability to develop the much larger and more complex flowers as well as deeper ovaries with more seeds -- that is to say, larger fruits -- that we see around us today."


'/>"/>

Contact: Jay Mayfield
jay.mayfield@tennessee.edu
865-974-9409
University of Tennessee at Knoxville
Source:Eurekalert  

Related biology news :

1. National Institutes of Health award Williams professor $217,710 research grant
2. NJIT architect professor advocates best-building practices for high wind regions
3. Professor Brian Greenwood awarded first Hideyo Noguchi Africa Award
4. McMaster University engineering professor receives Humboldt Research Award
5. USF professor gives historical look at physiology and WWII air war
6. NYU dental professor discovers biological clock linking tooth growth to other metabolic processes
7. MIT professor to discuss future of biofuels
8. ASU professor helps solve mystery of glassy water
9. Professors video series explains all facets of Earth
10. JDRF awards University of Copenhagen professor with grant to conduct innovative diabetes research
11. TAU professor finds global warming is melting soft coral
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
UT Knoxville professor finds unexpected key to flowering plants' diversity
(Date:1/25/2016)... , Jan. 25, 2016  Glencoe Software, the world-leading ... and publication industries, will provide the data management solution ... (NPSC). ... Phenotypic analysis measures the ... organisms, allowing comparisons between states such as health and ...
(Date:1/20/2016)... Jan. 20, 2016 A market that just ... benefit from the explosion in genomics knowledge. Learn all ... Research. A range of dynamic trends are pushing market ... personalized medicine - pharmacogenomics - pathogen evolution - next ... markets - greater understanding of the role of genetic ...
(Date:1/15/2016)... Puerto Rico , Jan. 15, 2016 ... big and small to find new ways to ensure ... culture. iOS and Android ... based on biometrics, transforming it into a hardware authorization ... that users swipe their fingerprint on their KodeKey enabled ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... 2016  The Maryland House of Delegates and House ... University of Maryland School of Medicine Dean E. ... Maryland Medical System President and CEO Robert Chrencik ... highest honor given to the public by the leader ... Reece and Mr. Chrencik for their contributions to ...
(Date:2/10/2016)... 2016 ASAE is introducing a hybrid membership ... (AMC) the option of joining or renewing through an ... by staff size, every employee in any size association ... reap all available member benefits.   John ... membership options will allow organizations of any size and ...
(Date:2/10/2016)... -- IsoRay, Inc. (NYSE MKT: ISR), a medical technology company ... for the treatment of prostate, brain, lung, head and ... for the second quarter and six months of fiscal ... --> --> Revenue was $1.19 ... ended December 31, 2015, a 12% increase compared to ...
(Date:2/10/2016)... , Feb. 10, 2016  Matchbook, Inc., ... for fast growing biotech companies, announced today the ... Procurement Strategic Advisor. Jim brings nearly 25 years ... and procurement, having spent nearly two decades in ... Chain/Logistics and Procurement at Genzyme and, most recently ...
Breaking Biology Technology: