Study illuminates origin of flowers

A study on Amborella, a plant of remarkable heritage, reveals new information about the origins of flowers on Earth.

Amborella hails from an ancient evolutionary lineage and scientists who sequenced its genome say its DNA provides conclusive evidence that the ancestor of all flowering plants evolved following a polyploidy event, during which an organisms entire genome is duplicated. It happened about 200 million years ago.

Because redundant copies of genes can evolve to develop new functions, this doubling may be behind Darwins abominable mystery the apparently abrupt proliferation of new varieties of flowering plants in fossil records dating to the Cretaceous period, about 145 million years ago.

Some duplicated genes were lost over time, but others took on new functions, including contributions to the development of floral organs.

The research was led by scientists at Penn State University, UB, the University of Florida, the University of Georgia and the University of California, Riverside.

A paper by the Amborella Genome Sequencing Project that includes a full description of the analyses performed, as well as implications for flowering plant research, was published in the journal Science on Dec. 20. The article is among three on different research areas related to the Amborella genome that will be published in the same issue of the journal.

Of more than 300,000 flowering plant species alive today, Amborella (Amborella trichopoda) is unique as the sole survivor of an ancient evolutionary lineage that traces back to the last common ancestor of all flowering plants, according to the research team. The plant is a small understory tree found only on the main island of New Caledonia in the South Pacific.

This heritage gives Amborella a special role in the study of flowers, says Victor Albert, UB professor of biological sciences, who played a key role in leading the research effort.

In the same way that the genome sequence of the platypus a survivor of an ancient lineage can help us study the evolution of all mammals, the genome sequence of Amborella can help us learn about the evolution of all flowers, Albert says.

Generations of scientists have worked to solve the puzzle of why flowering plants suddenly proliferated in fossil records, says Claude dePamphilis of Penn State, another lead investigator.

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Study illuminates origin of flowers