Exotic Amborella Flower Yields Secrets About Origins Of Blossoms On Earth, And Answers Questions That Vexed Darwin
"People from a planet without flowers would think we must be mad with joy the whole time to have such things about us," the British writer and philosopher Iris Murdoch wrote in her novel, A Fairly Honourable Defeat. A theory of how planet Earth became lucky enough to be graced with flowering plants was confirmed Friday in three articles in the journal Science addressing the sequencing of the genome of the plant, Amborella, a small green-stemmed, white-flowered understory tree found only on the main island of New Caledonia in the South Pacific. It is the sole survivor of the last common ancestor of all flowering plants.
Like Us on Facebook
The Amborella trichopoda is yielding genetic clues as to how flowers suddenly proliferated on the earth in the Cretaceous period millions of years ago — a mystery that in 1879 Charles Darwin termed in apparent frustrated fascination an "abominable mystery." The Amborella's unique evolutionary status has been known since Dr. Pamela Soltis, a botanist at the University of Florida and one of the study's co-authors, first reported on it at a national botanical meeting in 1998 and published a paper on it the following year.
The sequencing of the Amborella genome has provided conclusive evidence that the ancestor of our 300,000 flowering plants evolved following a "genome doubling event" that occurred about 200 million years ago. Ancient genome duplications are found in the early ancestor of vertebrates —which includes our own — and is associated with the origin of bony fishes. Where duplication causes redundancy, genes are rendered either inactive or shed from the duplicated genomes altogether. In the case of flowers, some duplicated genes took on new functions, including contributions to the development of floral organs.
"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," said Victor Albert of the University at Buffalo and co-author of one of the three articles, in a statement.
The newly sequenced genome of the Amborella plant also sheds light on the genetic origins of important traits in all flowering plants — including all major food crop species. "It's too early to predict the precise implications for crop plants," Soltis told the International Science Times, "but the availability of such a strong reference genome means that any traits of importance for crop improvement can be evaluated in light of plant evolution." According to Soltis, if we could better understand how a set of genes for disease resistance evolved early on, we could develop effective experiments to figure out how those same genes function in current crop plants.
"We can envision the genetic data from the Amborella genome to be immensely important for understanding the processes involved in the origins of traits that are relevant to crop improvement," Soltis said.
© 2012 iScience Times All rights reserved. Do not reproduce without permission.