Scientists have found a common ancestor of land-based plants

A is a wheel algae, B is a birgae algae, C is a twin algae, and D is moss. The genome is , however, what group did the common ancestor of the existing land plants originate from? How did the first truly green plant evolve and adapt successfully from aquatic to land- and land-based? Scientists have not stopped asking this long-disputed question.
cells answered these questions with a new study published on November 14th.
Team Cheng, a researcher at the Institute of Genomics of the Chinese Academy of Agricultural Sciences, and scientists from Germany, Canada and Russia have jointly demonstrated that a newly discovered twin-star algal single-celled green algae, Spirogloea muscicola, is the common ancestor of all land plants. Previously thought to be a number of transcription factors found in land plants, the "roots" of their ancestral origins can be found in the green algae genome. The paper reports that the common ancestors of land plants broke through the molecular mechanisms of drought adaptation to successful landings 500 million years ago, and for the first time reveals that land plant ancestors "borrowed" genetic material innovations from soil bacterial genes to drive the long land-based process.photoreal life originated in the ocean about 1.5 billion years ago and flourished in places with light and water. After living in the water for a billion years, life overcame the difficulties to land.Cheng
, the first author of the paper, told the China Science Journal that another work the team was involved in, an evolutionary analysis of transcriptional groups of 1,000 green plants, was recently published in the journal Nature. Scientists have found that throughout the evolution of plants, there were many "great leaps" in the transformation period, such as the origin of flowers, the origin of seeds, the origin of the tube bundle, and so on; The origin of the ancestors of land plants, i.e. land-based, involves a great deal of genetic innovation and gene family expansion, which is a key step in plant evolution. Plant land-based is a long and complex evolution process, in the tide ups and downs, Bohai Santian ups and downs, some geographical habitats appear periodic drying phenomenon, such as the formation of small puddles, riverbeds, offshore mud and so on. Plant ancestors began mixing with soil bacteria and developed new ways of obtaining nutrients, gradually empowering the first land plant and its descendants to adapt to harsh environments, eventually forming the rich and diverse land plant community we see today.The
" plant land-based event profoundly changed the entire ecosystem and was the starting point for the 'greening' and diversity of the Earth's surface, providing the basis for the survival and development of higher life, including oxygen, food, nutrition and natural medicines. "The paper's author, Professor Gane Ka-Shu Wong of the University of Alberta in Canada, said.
fact, in the course of life evolution over the past few billion years, there have been several groups of photochemical endurons that have successfully landed through drought adaptation.
But almost all fossil and molecular evidence suggests that the origins of existing land plants originated from a single landing event, and that their common ancestor belonged to a branch called a chain-type algae. Plant taxonomists and evolutionists have done different studies to analyze the simplest and most primitive base land plants, such as moss, moss/ horn moss.
Wong explains that in the past, most of the research has focused on streptomy algae living in fresh water or parts of the land, such as complex rotating algae or algae that are closer to land plants, and the much simpler branch of Zygnematophyceae.
"When we can't position the right species on the right system, a lot of biological and evolutionary questions don't answer well," Cheng said. " single-celled green algae Spirogloea muscicola has never been in the scientist's field of vision before.
because previous studies have tended to mistake complex moss, cyanobacteria, or macarptos more like higher tetanus plants for possible ancestors of their tetanus plants. And this newly discovered species, like most species of cyanobacteria, exists in single-celled or simple silky forms.
Melkonia, a professor at the University of Cologne in Germany and author of the paper, said the two species, Spirogloea muscicola and Mesotaenium endlicherianum, provided by the university's Center for Algae Species, had completed genome-wide sequencing in China."
Through systematic classification and comparative evolutionary genomics studies, it has been confirmed that Spirogloea muscicola is the first reported new species from a newly identified genus Spirogloeophycidae and the first to differentiate the base species of a cyanobacteria that is closest to the common ancestor of land plants.
Surprised scientists, the core gene families previously thought to be unique to only land plants, such as plant hormones, anti-reverse, drought-resistant, anti-UV, symbient with bacteria/fungi, are present in large numbers in this newly discovered species, and their cell walls are closer to those of land plants.
" Before landing, the genome and genetic metabolism of the cyanobacteria have been quite a genome innovation, obtained a large number of new genes or family amplification, in order to adapt to the land life has been ready for genetic material. Melkonian said.
, the team detected a significant recent genome-wide triple event in its genome. According to a transcriptional map of 1,000 green plants, genome-wide multiply events are extremely rare in algae, but some species in the cyanobacteria branch have richer multiply signals that can be detected.
" gene or whole genome replication is one of the important drivers of life's evolution from simple to complex. The relationship between the frequent occurrence of genome-wide replication events and their adaptation to the land environment is a topic that needs further study. Cheng said. graS and PYL are among the large number of genes shared by ancestral green algae and land plants.
GRAS is one of the star genes in plant research, which is functionally "multi-talented" and is related to many important metabolic pathways such as plant growth, development and resistance, while PYL gene is an important subject factor in the genetic pathway of ABA, the shedding acid.
scientists found that the two key genes in the ancestral green algae were "borrowed" from soil bacteria. "This is actually a 'genetic engineering event' that occurs naturally in the common ancestors of plants, which is often called a 'GMO' event, and is a key molecular driver of the adaptation of land plant ancestors to land habitats." Cheng said evolutionary analysis of molecular systems revealed that the horizontal gene transfer event, which originated 600 million years ago from soil bacteria, coincides with the fossil time of the plant land-based event.
scientists believe that this level of gene transfer is a key step in the "historic leap" in the function and adaptability of land plant ancestors, playing an extremely important role in the gradual occupation of the Earth by green plants over the next 500 million years.
era of genomics, systematic comparative evolutionary genomics is a powerful strategy to study the molecular basis of ancestral plant land-based studies at the genetic level. Cheng believes that it is an important part that agricultural breeders need to face today to get inspiration from the species resources of nature's diversity and to screen and excavate the target functional genes.
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