Plant evolution: landmarks on the path to terrestrial life.

Area of Science:

• Evolutionary Biology
• Plant Science
• Algal Biology

Background:

• Photosynthetic eukaryotes are diverse, but only land plants (embryophytes) transitioned to terrestrial life.
• Land plants evolved from streptophyte algae, likely related to Zygnematophyceae.
• The specific algal traits enabling this transition remain unclear due to mosaic and reductive evolution in ancestors.

Purpose of the Study:

• To investigate the key features of streptophyte algae that facilitated the transition to land.
• To address challenges in inferring the biology of the algal progenitor of land plants.

Main Methods:

• Analysis of molecular phylogenetic data to identify land plant ancestors.
• Review of recent progress in understanding algal trait evolution.
• Discussion of challenges posed by mosaic and reductive evolution in ancestral lineages.

Main Results:

• Identified streptophyte algae, particularly those related to Zygnematophyceae, as the closest algal relatives of land plants.
• Highlighted the complexity in reconstructing ancestral algal traits due to evolutionary patterns.
• Emphasized the ongoing effort to understand the algal toolkit for terrestrialization.

Conclusions:

• Reconstructing the biology of the algal progenitor of land plants is crucial for understanding plant terrestrialization.
• Further research is needed to overcome the limitations imposed by mosaic and reductive evolution in inferring ancestral traits.
• The study provides a perspective on the evolutionary steps from algae to the first land plants.