Seaweed lineage may be source of all green plants

Tuesday, November 23, 2010

Research by Buchheim, others to appear in Journal of Phycology

A team of researchers from across the United States and Belgium, including three members from The University of Tulsa, say they have found “living fossils” in the form of seaweed more than 650 feet deep in the ocean.

The seaweed is a form of alga that had been identified by other scientists as Palmophyllum from New Zealand waters and Verdigellas from the western Atlantic Ocean. However, little research had been done regarding the algae’s origin.

The algae are multicellular, but, unlike other green seaweeds and all land plants, their cells do not form complex tissues. The team discovered that both types of algae form an ancient group of green plants and should be assigned their own order.

The algae require little light to survive, and in deep waters, the plants face fewer challenges from scouring by waves or currents, temperature changes and grazing animals. The research team suggested that these factors may have contributed to the longevity of this algal lineage that is estimated to have been around for more than a billion years.

Researchers from TU include Dr. Mark A. Buchheim, professor of biological science, as well as former TU research associate Julie A. Buchheim and former graduate student Bindhu Verghese (PhD ’07). The team’s findings were to be published in the December issue of the Journal of Phycology.

The TU research group is part of an alliance of researchers, informally called “deepestgreen” whose goals include an assessment of plant origins. Professor Buchheim noted that the results from this investigation “challenge the current origins hypothesis for the progenitor of all green plants. The prevailing hypothesis favors a motile cell as the ancestral form for green plants, but the new data indicate that Palmophyllum and Verdigellas, which are non-motile, may predate any motile cell lineage.”

Buchheim also said, “The broad relevance of this basic research is in our improved understanding of the origin of land plant traits, ultimately influencing our knowledge of organisms like rice, wheat, corn and soybean.”


Mona Chamberlin