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Establishment of a Clonal Culture of Unicellular Conjugating Algae
Published on: July 14, 2018
Streptophyte algae and the origin of embryophytes
Burkhard Becker1, Birger Marin
1Botanisches Institut, Universität zu Köln, Gyrhofstrasse 16, Köln, Germany.
Annals of Botany
|March 11, 2009
Summary
The evolution of land plants began with freshwater streptophyte green algae, which developed key traits before colonizing land. Understanding their genome is crucial for tracing plant terrestrial adaptation.
Area of Science:
- Evolutionary biology
- Phycology
- Botany
Background:
- Land plants (embryophytes) evolved from streptophyte green algae.
- Streptophyte algae exhibit increasing cellular complexity, with Charales often considered sister to land plants.
- Key cellular and physiological traits originated within streptophyte algae before the evolution of land plants.
Purpose of the Study:
- To investigate the evolutionary history of streptophyte green algae and their relationship to land plants.
- To understand the origin of traits essential for terrestrial life.
- To reconstruct early evolutionary events leading to land plant colonization.
Main Methods:
- Phylogenetic studies using molecular data.
- Analysis of genome evolution, including protein families and polyadenylation signals.
- Reconstruction of evolutionary events using molecular phylogenies and the fossil record.
Main Results:
- Mesostigma and Chlorokybus represent the earliest divergence within streptophytes.
- The sister group relationship of Charales, Coleochaetales, or Zygnematales to embryophytes remains debated.
- Many molecular traits previously thought unique to land plants predate the Chlorophyta/Streptophyta split or originated in streptophyte algae.
Conclusions:
- The Streptophyta/Chlorophyta divergence is linked to a preference for freshwater/marine habitats.
- Early freshwater adaptation of streptophyte algae provided an advantage for early land plants.
- Complete genomes of key streptophyte algae are needed to understand terrestrial colonization.
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