Klebsormidium

Differential interference microscope image of Klebsormidium flaccidum strain NIES-2285. K. flaccidum consists of non-branching long filamentous cells. Each cell contains a large chloroplast, which is positioned against the cell wall (parietal chloroplast) and contains a pyrenoid. Arrowhead indi-cates a pyrenoid surrounded by a few starch grains. Scale bar = 10 mm. Source: Phys.Org/Yu Yonehara

In Phys.Org, Yu Yonehara notes the breakthrough research from the Tokyo Institute of Technology on the connection between early marine algae and the development of terrestrial life: “The colonisation of land by plants was a key event in the evolution of life,” point out researchers in Japan in a recent report. The transition provided the nutrients and oxygen that allow terrestrial creatures to survive, yet so far there has been little evidence of the stages in the evolution of plants that allowed them to adapt from aquatic life to conditions on land.

Lead researcher Hiroyuki Ohta from Center For Biological Resources and In-formatics/Earth-Life Science Institute, Tokyo Institute of Technology.

Lead researcher Hiroyuki Ohta from Center For Biological Resources and In-formatics/Earth-Life Science Institute, Tokyo Institute of Technology.

A collaboration of researchers, led by Hiroyuki Ohta from Center For Biological Resources and Informatics/Earth-Life Science Institute, Tokyo Institute of Technology in Japan, has now identified features in the genome of a simple terrestrial alga that represent key evolutionary milestones for surviving in the more severe environments found on land.

The ancestors of present land plants are widely believed to be charophytes, a division of green algae that are distributed throughout the world. The charophyte Klebsormidium is a very simple multicellular organism and most species that have adapted to live on land can also live in water.

Despite the potential significance in the evolution of life, so far genome sequence data for charophytes has been fragmentary. Ohta and his team of researchers, which included scientists from several institutions in Japan, analyzed the genome of the terrestrial Klebsormidium flaccidum and compared it with other algae and land plants.

The comparison suggests that many of the genes required to survive on land were already present in the ancestor of K flaccidum. The researchers also identified genes coding for mechanisms to respond to environmental stimuli and to protect against high intensity sunlight.

The researchers conclude their report: “Our analysis provides evidence that K. flaccidum has the fundamental machinery required for adaptation to survival in terrestrial environments.”