The report, “The Penium margaritaceum Genome: Hallmarks of the Origins of Land Plants,” was published May 21 in the journal Cell.
Penium margaritaceum belongs to a group of freshwater algae called charophytes, and specifically to a subgroup called the Zygnematophyceae, which had a common ancestor with the first land plants some 600 million years ago. In order to shift from water to land — a transition that still puzzles scientists — plants had to protect themselves from drying out and from ultraviolet (UV) radiation, and they had to develop structures to support themselves without the buoyancy provided by water.