Plants turn energy from sunlight into bioenergy through a chemical process called photosynthesis, which also produces oxygen in its breathable form. However, photosynthesis can also generate an alternate form of singlet oxygen, which is a highly reactive and toxic substance that destroys biological molecules.
"We've discovered a pathway that cells use to turn on certain genes and respond to singlet oxygen," says Timothy Donohue, a professor of bacteriology in the university's College of Agricultural and Life Sciences and lead researcher on the paper.
"This finding should make it possible to modify plants and other photosynthetic cells to avoid the toxic effects of singlet oxygen, which could impact agriculture and the treatment of human and plant disease, and aid the effort to create alternative bioenergy sources," Donohue says.
Donohue and his group studied a photosynthetic microbe and identified the cellular pathways it used to sense the presence of singlet oxygen and defend itself from this toxic substance. He notes that the response mechanism is likely highly conserved across species from microbes to plants and humans - and therefore very applicable to other fields of study.
For example, too much sunlight can actually be harmful to plants, because the heightened photosynthetic activity also means an increase in singlet oxygen. By modifying plants to enhance the protective pathway, "we could be able to get larger crop yield per photon of light," he says.
And by making cells more resistant to singlet oxygen, scientists may be better able to design bioenergy systems that us
Contact: Tim Donohue
University of Wisconsin-Madison