Botany, Plant News
That green muck you see on a pond’s surface is one step closer to becoming a solar-powered source of some of the stuff you use everyday. Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Stanford University have developed a way to send molecules and proteins across the cell wall of algae, a feat that opens the door for a new way to study and manipulate these tiny organisms.
In recent years, algae have become a hot prospect as a way to synthesize biofuels, chemical building blocks, vaccines, pharmaceuticals, and other useful compounds. The idea is to engineer algae to secrete fuel for your car or other compounds using sunlight as an energy source and carbon dioxide as a carbon source.
The discovery that an ancient light harvesting protein plays a pivotal role in the photosynthesis of green algae should help the effort to develop algae as a biofuels feedstock. Researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) have identified the protein LHCSR as the molecular “dimmer switch” that acts to prevent green algae from absorbing too much sunlight during photosynthesis and suffering oxidation damage as a consequence.
“We’ve shown that for green algae, and probably most other eukaryotic algae, the LHCSR protein is used to dissipate excess light energy and protect the photosynthetic apparatus from damage,” says Krishna Niyogi, a biologist who holds joint appointments with Berkeley Lab’s Physical Biosciences Division and the University of California (UC) Berkeley’s Department of Plant and Microbial Biology. “We describe LHCSR as an ancient member of the family of light harvesting proteins because it seems to have been one of the first to branch off from a common ancestor shared long ago by both algae and plants.”
The kelp forests off southern California are considered to be some of the most diverse and productive ecosystems on the planet, yet a new study indicates that today's kelp beds are less extensive and lush than those in the recent past.
The kelp forest tripled in size from the peak of glaciation 20,000 years ago to about 7,500 years ago, then shrank by up to 70 percent to present day levels, according to the study by Rick Grosberg, professor in the Department of Evolution and Ecology and the Center for Population Biology at UC Davis, with Michael Graham of the Moss Landing Marine Laboratory and Brian Kinlan at UC Santa Barbara.
New technique allows gene-expression analysis
The shoot apical meristem continues to make leaves, flowers and branches throughout a plant's life, so it must contain stem cells. These reside in a complex three-dimensional structure consisting of perhaps three dozen stem cells surrounded by niche cells and millions of differentiating cells. This makes the stem cells within the meristem hard to isolate. In fact, most researchers pursuing genomic studies of plant stem cells have turned instead to roots. Now, using an Arabidopsis thaliana mutant that produces an unusually high number of accessible shoot apical meristems, G. Venugopala Reddy of the University of California, Riverside and his colleagues have found a way to study shoots and have produced a gene-expression map of the meristem that reveals the molecular signatures of these elusive stem cells.