Amborella DNA sequences shed light on the origin of flowering plants

(scienceinfo.net) - DNA of legendary plants provides insight into the evolution of flowering plants.

A new gene sequence of plants called Amborella indicates Darwwin's 'unpleasant secret' theory - the question is why the flowering plants suddenly flourish on Earth millions of years. before. The gene sequence of this species sheds light on a major event in the history of life on Earth: The origin of flowering plants, including all major food crops.

On December 20, 2013, an article made by the Amborella Genome Sequencing Project (Amborella Genome Sequencing Project) included a complete description of the analysis carried out by this project, as well as applications. For flowering plant research, was published in Science magazine. This article is one of three different areas of research related to Amborella's genome, which will be published in the same issue of this journal.

Amborella (Amborella trichopoda) is the only surviving species of an ancient evolutionary strain and the last trace of the ancestors of all flowering plants. Amborella is a small canopy tree found only in the main island of New Caledonia in the South Pacific. An attempt to decipher the sequence of genes of this plant made by scientists at Penn State University, University of Buffalo, University of Florida, University of Georgia and University of California - Riverside has discovered Evidence of evolution, this evolution has paved the way for the amazing variety of more than 300,000 species of flowering plants we see today.

This unique heritage gives Amborella a special role in the study of flowering plants. ' Same way as studying platypus gene sequences - an ancient animal that still lives today - can help us study the evolution of all mammals, Amborella's gene sequences can Help us better understand the evolution of flowering plants , 'said Victor Albert of the University of Buffalo.

Scientists who sequenced Amborella's gene sequence said the gene sequence of this plant provides convincing evidence that the ancestors of all flowering plants, including Amborella, develop after one . Genome duplication ' happened about 200 million years ago. Some duplicated genes are lost over time, but others have taken on new functions, including contributions to the development of flower parts.

'Duplicating genes may be an explanation for Darwin's' unpleasant secret '- a sharp increase in the flowering plants in fossils dating from the Cretaceous', Claude Penn State's Pamphilis said: 'Many generations of scientists have worked to decipher this mystery' , he added.

"Amborella's sequencing comparative analyzes are providing scientists with a new perspective on the genetic origin of important traits in all flowering plants - including all species. Because of the important location of Amborella, its genetic sequence is a reference gene sequence that allows us to better understand the genetic changes in flowering plants. Later development, including the genetic evolution of our multitude of crops - is therefore very important for improving productivity , 'said Doug Soltis of the University of California.

'Like another example of the value of the Amborella genome' , Joshua Der at Penn State University emphasized. 'We estimate that at least 14,000 protein-coding genes existed in the last common ancestor of all flowering plants. Many of these genes are unique to flowering plants, and many are important for flower production as well as other structures and the specific process for flowering plants. "

'This study provides insight into the genetic differences of flowering plants compared to all plants on Earth , ' said Brad Barbazuk of the University of Florida, 'and it provides evidence. New to the way that plants with seeds are genetically different from those without seeds'.

Jim Leebens-Mack from UGA notes that: 'Amborella's gene sequence facilitates the reconstruction of the gene passed down by the ancestors into' core eudicot ', a group of plants. accounting for 75% of all types of angiosperms. This group includes tomatoes, apples and beans, as well as timber trees such as oak and poplar trees. As an outsider of evolution to this diverse plant group, Amborella's gene has allowed scientists to estimate the linear arrangement of genes in an ancestral two-gene plant gene and to deduce specific changes in seed flow properties that have occurred over 120 million years in the evolution of double-leaf plants.

At the same time, Amborella seems to have acquired some unusual genetic properties since it separated from the rest of the flowering plants. For example, DNA sequences that can alter positions or superimpose in the genome (transposition factors) seem to have stabilized in Amborella's genes. Most plants show evidence of the current outbreaks of highly variable DNA activity, 'But Amborella is unique in this because it does not seem to reach many volatile sequences within a few million last year , "said Sue Wessler of the California-Riverside school. The inclusion of some transposition factors may affect the expression and function of protein-coding genes, so the cessation of mutable DNA may slow the rate of evolution to the whole structure. gene structure and gene function.

In addition, in addition to its benefits in retrospective studies of the evolution of flowering plants, Amborella's gebe sequence allows for a deeper look at the history and conservation of Amborella populations. There are only about 18 populations of these very special angiosperm species in high mountain areas in New Caledonia.

'DNA sequences of individual Amborella plants show geographical structure with conservation applications plus evidence of a major genetic bottleneck recently ,' noted LPam Soltis of the University of Florida. Similar narrow genetic variants occurred when humans migrated from Africa to obtain modern Asian-European populations.