New twist on life's power source

“This discovery represents a paradigm shift in our view of photosynthesis by organisms in the vast, nutrient-starved areas of the open ocean”, says Joe Berry of the Carnegie Institution’s Department of Global Ecology. “We had assumed that like higher plants, the goal was to make carbohydrates from carbon dioxide and store them for later use as a source of energy for any number of cellular functions or growth. We now know that some organisms short-circuit this complicated process, using light in a minimalist way to power cellular processes directly with a far simpler and cheaper (in terms of scarce nutrients such as iron) photosynthetic apparatus. We don't know the full significance of this finding yet, but it is certain to change the way we interpret optical measurements of photosynthetic pigments in the ocean and the way we model ocean productivity.”

Wolf Frommer, director of the Carnegie Institution’s Department of Plant Biology, agrees about the discovery’s ground-breaking importance. “If we thought we have understood photosynthesis, this study proves that there is much to be learned about these basic physiological processes. The findings of Grossman’s laboratory together with previous evidence reported by Greg Vanlerberghe from the University of Toronto showing that the gene encoding PTOX appears to be widespread in marine cyanobacteria will add depth and a mechanistic foundation for the modeling of primary productivity in the ocean.”

*Authors: Shaun Bailey, Anastasios Melis, Katherine RM Mackey, Pierre Cardol, Giovanni Finazzi, Gert van Dijken, Gry M Berg, Kevin R Arrigo, Jeff Shrager, Arthur R Grossman.

+Authors: Katherine RM Mackey, Adina Paytan, Arthur R Grossman and Shaun Bailey

The Carnegie Institution (www.CIW.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.