First Moss Genome Decoded

A group of international scientists from more than 40 institutions have successfully completed the first genome sequence for a nonvascular land plant, the moss Physcomitrella patens. Moss belongs to a group of plants called bryophytes. Bryophytes lack specialized tissues for circulating fluids. They neither flower nor produce seeds, but propagate via spores. Because of these features, scientists believe that bryophytes are the ancestors of angiosperms (flowering plants).

By comparing the moss genome from that of angiosperms and unicellular algae, the scientists gained valuable insights about plant evolution. The sequence revealed genomic changes related to the evolutionary movement of plants to land. These include: loss of genes associated with living in an aquatic environment, attainment of genes for tolerance to terrestrial stresses like temperature fluctuation and water availability and development of hormone signaling pathways, especially the phytohormones auxin and abscisic acid which coordinates multicellular development and response to drought stress.

Since the moss genome is much simpler compared to genomes of angiosperms, scientists can study the molecular mechanisms involved in important plant physiological processes like cell wall synthesis and assembly. In addition, scientists can also target and delete specific moss genes and study their functions in important crop processes.

The abstract of the paper published by Science is available at http://www.sciencemag.org/cgi/content/abstract/1150646 The news article is available at http://www.jgi.doe.gov/News/news_12_13_07.html