Researchers Show How Plants Protect Photosynthesis from Oxygen

A research team from Carnegie Institution for Science, Pennsylvania State University, and the University of Wyoming has identified a key protein that provides insight on photosynthesis back in the early days of life on Earth.

Photosynthesis takes place in two stages. During the first stage, light is absorbed and used to produce energy molecules, with oxygen as a byproduct. These energy molecules power the ‘second stage' of photosynthesis, in which carbon dioxide from the air is fixed into carbon-based sugars, such as glucose and sucrose.

Working with the green alga Chlamydomonas, the research team focused on the protein CGL71, known to be involved in assembling proteins required in the first stage of photosynthesis. But little about CGL71's role in this process was understood until now. The team found that CGL71 protects the photosynthetic apparatus from oxygen during its assembly. The process needs to be protected from its own byproduct because oxygen is a highly reactive molecule that can disrupt the iron-and-sulfur-containing clusters of proteins that are crucial to photosynthesis. Like CGL71, these clusters are critical for the first stage of photosynthesis, where electrons move to create energy molecules.

For more details, read the news release at the Carnegie Institution for Science website.